Picture of Concrete Lightbulb Wall Hook
This is how to make an excellent excuse for driving a lag bolt into your wall, the Concrete Lightbulb Wall Hook. Functional yet sylish, it gives a nice industrial design feel wherever you mount it.

Last winter after breaking out the serious cold weather gear, I found myself fighting the coat rack next to the front door. It was, to put it bluntly, failing miserably. Tipping over, breaking off, it was a mess. I swore before the next winter I would drive some serious hooks into the wall that would handle all my heavy overcoat needs. I just haven't seen any kickass hooks yet that I liked enough to justify making serious holes in my walls.

Cut to the last few months. As mentioned in my blog ( here, here, and here) I've been playing around, trying to make a concrete lightbulb. Why? Because I find the contrast of blending a new material like concrete in an everyday shape like a lightbulb to be a great design element. So while messing around with these guys, I realized this would be a great excuse to drive lag bolts into my wall for hooks. By embedding a lag bolt into the concrete lightbulb, I could make a wall hook that was useful enough to handle anything I wanted to hang off it. Thus this project was born.

This is an entry in the Etsy/Instructables SewUseful Contest, so if you love this idea but don't want to make it yourself, not to worry! I have them for sale in my Etsy Shop. Click here to order yours today! Yes, it's an entry into a sewing contest without any sewing. Sometimes you just gotta.

Check out my other entry into the SewUseful Contest (also without sewing!) - "Big Brass Ones"
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bbranchick1 month ago
You can clean the lightbulb with salt. Pour some salt into the lightbulb and shake it around. The salt removes the white powder
benny80253 years ago
I made a door handle of gypsum instead of concrete. I wanted the glass to be on the handle, but the gypsum got realy hot under the hardening, and the glass cracked. So I took the glass of and the result was better than i hoped for
Benny8025,what is gypsum? Plaster of paris? I know it's found in drywall.
Where did you buy it for your project?Thanks Elljayq
Hobby shops
serious winter gear? for me that means wearing socks with my sandals...loved the intructable...nice work
Here in sa
Winter entails :
Sleeveless t shirts
short pants
and crocs
here in des moines Iowa we have gotten about a foot of snow in one night... everything closed down except for the des moines public school district (dmps). they never close for anything..... also I do not like the cold at all!!!!! I lived I tucson Arizona before Iowa and I am used to highs of 110 degrees F.........
Sadly, that's what my winter hase been like this year--and I live in Colorado. It's a sorry state of affairs when I can wear a short sleeve shirt in Febuary. >_<
sorry to hear that...I am looking at 75 degree days but 40 degree nights..could use some the tourists away and make beach parking easier..Perhaps you will get the snow you need
Irock1483 years ago
closet door handles
yes..... you just added more brilliance to already existing brilliance... ☺☺☺☺☺☺
SIRJAMES098 months ago


I need to make 1...or 3....dozen. :0)

these would make great stocking stuffers for Christmas!! Birthday presents! I can think of a million & one reasons for giving as gifts!

TY for sharing. :0)

When separating the glass from the concrete hanger, I was thinking, about why you can not use a rag to wrap the hanger/bub in?

It will stop the glass from flying, contain the glass in 1 area/spot/whatever, and when finished, just toss the rag into the trash.

Granted, you still have minute particles of glass to deal with, but as you said, a shop brush should take care of that.

caperuzita8 months ago

Nice Idea!!!

In one side I've been thinking on how to recycle soiled light bulbs but I didn't find it any easy myself.

In the other I love to hang my stuff on doors to get them more availableand keep a roomier wardrobe, but this kind of hungers aren't so easy to find, most of them fall down to the floor within the first week.

Good luck selling them!!

oldaugie9 months ago
This looked like fun so I gave it a try. unfortunately I could only find hydraulic cement which sets in about 5 minutes. to add to my woes, I got the piece all put together (bolt not straight but, all else looked good for a first try) but then dropped it the following day. the bulb came off easily but it is !missing the shininess of the one in the 'ible. Someone suggested using polishing compound which helped some but I think I'll end painting this one to cover the flaws.

After painting, I intent to drill through a porcelain fixture and insert the cast into it as if it were a real light. I wonder how many folks it'll fool! perhaps I should use space under the porcelain fixture as a safe. talk about mixing content.

For a first try not too bad though. I've now got some mortar mix and am anxious to give my next one a try.

Does anyone know how to safely dismantle a cfl? I think one of those would be fun to try as a cast.

happy casting
kculver19 months ago
Instead of a toothbrush & soapy water table salt will take that white residue right out just put a spoon full of salt in the light bulb hold ur thumb over the end & shake it it will clear it right up!
SIRJAMES0910 months ago


the way we go through lightbulbs around here, I won't have to buy any...

Very nicely written, very educational,....can't wait to make a few(dozen) myself. :P

gungajin10 months ago

Absolutely great! This is one of the finest exponents of creative thinking. Reminds me on Picasso abstract paintings: so simple, everybody can do it. But only good old Pablo actually could.

thundercookie10 months ago

one question, how do i make it?

pbminecrafter10 months ago


pbminecrafter10 months ago

one question, how do i make it?

crhay10 months ago

This is a fantastic idea actually! My husband and I are trying to go with a very contemporary, modern style in our home. Having concrete lightbulbs for coat hangers would go perfectly with our theme. I will have to check first, but I think that my husband will love them too!
Cambria Rhay |

aloew11 months ago

I wonder if a different, less messy (no broken glass each time) way to do this would be to perhaps make a 2-part urethane mold of a lightbulb. You get the same accuracy, and can pull many parts from the mold over time. Also, there are good concrete mixes that will cure in under an hour with very nice results.

karcsika92211 months ago

This was my first instructables that I watched here,back in the days. Now I found it!

blending of concrete in an everyday shape like a light-bulb is genius. congrats..

challes11 year ago
I hope you don't mind...I placed a link to your site on my site... needed good instructions for hollowing out the light bulb and urs are very clear...thanks

That is a pretty awesome idea. I love to learn about little things like this that really improve on a lot of the things you would just buy in the store without thinking about it. I'll have to try that.


Xavier Smith |

x burn1 year ago
angry king1 year ago
i use your idea to make this
Adorei a ideia. Parabéns!
bluumax1 year ago
I was reading another instructable on concrete balls and remembered this one. Anyway I saw a post about using expansive cement and thought if it doesn't expand so much it trashes the metal, doubtful, it might make this a lot easier as it breaks the glass away for you. It has a nice looking finish too.

noahspurrier says: "I make cement spheres the same way! I use pure expansive cement (AKA expansion cement) with no aggregate, which creates a different look. It has no aggregate and no voids. The expansive cement has one advantage in that it actually cracks itself out of the glass mold."
qewt2 years ago
Love that sheen on the concrete!
arth2 years ago
could you use plaster of paris instead of concrete?
Honda Enoch2 years ago
I might try this with an energy bulb for that twisted look. :)
catmanduud2 years ago
its cool but whats it for
See the last photo?
blazygut2 years ago
lets just be concrete here,for a second
Chad Baxter2 years ago
I mean, what's better than breaking glass right?!
bbondy2 years ago
Hi Sir! it's a very provocative tutorial and very nice product as a result. I tried once with colored grout as an exercise and I want to show you the result.
as you see the area around the metal circle is not connected well because i didnt clean the internal glass completely (little bit hard).
Now I have the other lamp with bolt and the wet grout in it. i cant wait to see the result by tomorrow. thank you and keep posting other tutorial. :)
bbondy bbondy2 years ago
ah i see we can post image in this comment. here it is
This is beyond awsome! May I ask what your inspiration was? i might try to do an installation using a ridiculous amount of these...maybe 200-250?
whamodyne (author)  SleepyWindows2 years ago
My inspiration was a desire to play with form and iconic shapes in ways that made people stop and think about it for a moment. That and a need for a serious hook to hang stuff on.

If you need 200+ of the wall hooks, I would be happy to supply them if you want. I still make and sell these and by now have made hundreds of them, one at a time. I could do a serious batch run if you wanted that. Please send me a note if you are interested. - Ray
Skymeat2 years ago
I just made a couple of these. Great idea! I changed the recipe a bit, which might make it safer and a bit easier.

1) I used a pair of dikes to snip off the metal button on the end of the bulb. This exposes the bare blue glass and has a dimple for a small tool.

2) A very small drill bit was used to tap against the exposed hole, creating cracks in the glass (Hold the bulb and bit in one hand and tap the bit on a concrete floor, most any other surface won't work. Just do it 20-30 times and let gravity do most the work)

3) Once the blue glass cracks use needle nose pliers to pick at the fragments, the first one is the hardest. Just get the blue glass at this point.

4) You should have the blue glass out and be looking into the sealed bulb. Insert the needle nose pliers as deep as they'll go and give a little tension on the handle till the inside breaks.

5) Use the needle nose closed to ream out the glass, you'll end up with an almost perfect hole. Just go a little at a time. Don't try and do it all at once.

6) Clean it out. Fill the bulb with a couple tsps of Morton salt. Cap the end with a thumb and shake it. Dump out the salt and repeat a few times. It will be perfectly clean and shiny.

7) Rinse and prepare concrete. The inside can still be wet, it's getting filled with concrete anyway.

8) I used off the shelf concrete mix (5000psi), but screened it to 1/8" (took out rocks larger than 1/8", so mortar mix is about the same thing) But I mixed it a bit wetter than the photos here. The consistency was about like wet oatmeal, and was pourable (Not easy to do, make it a bit too wet and add spoonfulls of powder to get there). I used a funnel to pour the mix into the bulb.

9) Wait 7 days. 3 day cure is a bit too soon to be really hard. Best if you wait 28 if you want a very hard concrete but no one will do that.

10) Break the glass off. I used a 5 gallon bucket filled with water and submerged the bulbs and tapped gently with a steel bar. I mostly brushed off the remaining glass with the leather gloves I was wearing.

11) Dry thoroughly. The concrete sucks up a lot of water. This is where I am now. I plan to let them dry for a couple weeks in a warm dry location then seal. I was left with very smooth and perfect bulbs without any bubbles and certainly concrete in the 7000psi+ range :)

I would love to see some photos of this. May I suggest you make your own instructable?
cincymikeb3 years ago
walked into the bathroom this morning and was GLAD to see a burnt out bulb !
Yaaay another wall hook !
yea, recycle
mganpate2 years ago
its very nice consept kindly share the pdf on
stealthop2 years ago
im fairly shocked you broke the glass off to be honest
stealthop2 years ago
you can dump some rice into the bulb and give it a shake. it will clear the white powder in no time without water .
shazni2 years ago
hi...i've collected some bulbs and then i tried to hollow it...i tried..i tried and TRIED!!! the black thing doesn't come out! i even tried to drill a hole...nothing is happening!!! please tell me what i am doing wrong? the silver led just came out when i used a dremel to cut off ...but the black thing is not i use fire?? i'm scared if the bulb will burst in my face
azharz2 years ago
Nice Instructable, and I have an idea for you why not mix it with poster colour so the concrete bulb have shiny colour.
asteidl3 years ago
Haven't got solid plans for my afore-mentioned home-made tool idea, but I do have some ideas, revolving around and a big nail, a battery pack, and a few zip-ties.
asteidl3 years ago
A miniature concrete vibrator would be perfect for this project, I've seen enough concrete work in construction, I may try to make one, for this and similar projects. Concrete seems to be a great medium for functional art, being that it's cheap, strong, and durable, and can take a decent finish.
 You could also just use clear unfinished bulbs. Great ible. TY.
I second that. Using clear bulbs will save much drying time cleaner and effort.
vknutt3 years ago
Another little trick to removing the white powder coat is, once you have removed the filament, 1/2 fill the bulb with Methylated Spirits and about 2 tbsp of uncooked rice. Then cover the end and shake it up.

This will remove the coating without any scratches (not that that really matters in this case) and also removes the chance of getting a too over eager when cleaning with a toothbrush/bottlebrush and pushing through the glass (as I have done more times than I'd like to admit).
cincymikeb3 years ago
Think I'll paint one white and write 60 watt on the bottom.
cincymikeb3 years ago
Not having a scribe handy I used a deck screw .after using the tip to break the purple glass, I ran the screw up and down using it like a file .it worked great to clean up the inside edges.
teja80455 years ago
hey i have a doubt that cement won't gets harder if there is no air how can we get it ?????can u reply me plz....................
concrete cures best when it is not exposed to air. a 3000 psi rated mix will easily test to 5000 psi when kept in a sealed environment for a sufficient time.

concrete does not air dry like clay. it is a chemical reaction that causes it to harden, similar to an epoxy.

in fact during the construction and repair of bridges, oil wells, hydrolic cement is used and it will cure underwater. remember the well repair in the gulf of mexico?

the curing in a light bulb would be near perfect and if left long enough it would have the same tensil strength as granite or even greater.
The cement doesn't need air to dry!
Aquilla3 years ago
I see you sell these on your Etsy store.

If you experimented with making these partially hollow (perhaps using a liquid filled balloon), you could probably reduce the amount of cement used, and their weight without making them so thin as to be too fragile.

If the weight is reduced bellow their current shipping category, you could perhaps both increase your profit margin AND pass on some of the savings to your Etsy customers too.

Just a thought. Love these alot, as soon as I'm not renting I plan on giving them a go.. Best wishes.
higherlife6 years ago
Don't try this with those energy efficient bulbs. If they break, it leaks mercury and you have to leave your house or at least fifteen minutes.
I agree. It's better to not mess with mercury than to have to deal with potential of contamination. There is a proverb dedicated to the mockers and scoffers. Mercury tends to make people stupid, and well, the results are that stupid people take unnecessary chances both with their own health as well as the health of others. I wish we could all be smart, but then we wouldn't have the entertainment of the The Darwin Awards. You know what they say... an ounce of prevention is worth a pound of cure.
please people, dont listen to higher life about mercury leaving for 15 minutes
i dont know if the energy 1s contain it but either way, mercury is a heavy metal, just carefully remove it(brush it on to a piece of paper) and remove it from your house(dont ask me how to dispose of it as the epa doesnt like what i'd say)
but i've been playing with mercury on and off my whole life and it hasnt hurt me although mercury poisoning is a real danger
but leaving the house for 15 minutes will NOT do anything as to removing it, it will still be there when you get back
Doncha just love the over reaction people have have to things that mostly only have potential to do harm? A school near me got evacuated because a mercury thermometer got broken in the science lab. They called in a very expensive clean up crew, to clean up only enough mercury to harm one if they collected it all and enjested it. Maybe it had potential to harm more if it got vaporised, maybe. Concidering it was spread around the room the process it would have taken to vaporize it would have posed more danger. :)

BTW, Good instructable, because of it I'll be using mortar mix and covering my forms with glass for my plant containers, it will take less work to polish them.
The so-called "long life energy efficient" lightbulbs (we've had 3 or 4 die already) contain mercury and should be disposed of at a hazardous waste facility.  You can find one in your area by calling the local recycling company.   !
 I know there are warnings on the package I bought. I am concerned that people take extra care while tinkering. Sometime our enthusiasm overtakes our common sense. PLEASE, Don't be so non-chalant with your health or the health of others. I know on this website, that's like blasphemy or something. But, my motherly instincts often jump the gun for preventive measures.

All that aside, I think it is a fantastic project, though.
are you talking about CFLs?
ie, the SPIRAL light bulbs?
they are a special class of floresent that has the ballast and everything built in
hm... cement wouldnt work for this as the thin diameter of the tube would be too fragile as a coat hook
but maybe epoxy, anyone wanna try it?

cfls DO contain mercury but i've yet to encounter a incandecent with mercury in it
"if" they break? When you do this aren't you supposed to break it? I mean of course it's gonna leak mercury and you should leave your house but its gonna break anyway, right? Even with one of those bulbs I wouldn't use it because it would either look really cool or really bad in the end. Plus it would probably break much easier. No offence to you or anything.
no offense taken. It just that I had mercury poisoning from those freakin bulbs. My neurological system went wacko for a while. We need to be careful.
you dident have mercury poisoning. you had a variation of heavy metal poisoning due to your protein intake 
gez higherlife5 years ago
this kind of bulbs doesn't contain mercury. it think, your accident was because of fluorescent lamps. all of them contain freaky gases. -and, even if you know what you're doing, while modifying this bulbs by breaking, you shouldn't handle them with bare hands. you should wear painting gloves at least. broken glass is too sharp, it can easily pierce through your hand.
ilike2make4 years ago
Don't brush your teeth with that toothbrush.
I heard glass dust was good for your tongue.
jason kb3 years ago
think i could substitute the lag bolt for a wood screw?...or would that be too...weak?
i was thinking of screwing it into my door cuz i need a door hanger, but my doors a bit hollow and flimsy :P
MrSmoofy4 years ago
Why is the concrete so shinny after the glass is removed?
Cement is a fine powder and the cement mix will pick up the texture of whatever it is cast in. For example cement cast in a wooden box will pick up the wood grain.

When cast in glass like it is here, the cement takes the smooth texture of the glass, so it's nice and shiny
so, in theory, the cement in a wooden box would look like a wooden cube?
yes and no. hes saying that it would look like wood but not have the color of wood. if you made a face mold out of concrete (not saying you should, ouch) it would look and feel like your face, but it wouldnt have the colors. it might even have some hair, though :)
ah, so it takes the texture of whatever its cast in?
Apart from colour, yes.
It picks up the texture surprisingly well. If you ever see any buildings cast with wooden forms you could easily mistake the walls for painted timber.
Dude that's fawesome I wan't my house to look like that
Spydamonky3 years ago
I see, I thought it was just a concrete filled bulb. Cool idea! might just make one this weekend!
mschmidt13 years ago
Eine gute Idee, die ich mal machen muss!

A good idea that I must make time!
jumper173 years ago
That caption on the last picture of this step threw me off. I have a tendancy of not finishing what I start, so I went to my oven and set the pre-heat to 375. Then, after setting the timer as well, I came back and finished reading the caption. I did my first ever, REAL facepalm today.
flyingpuppy3 years ago
No wonder it wasn't working for me. I've been mixing the concrete way too thin so I could pour it in. I should read instructions before attempting things. :)
BrianJewett3 years ago
Instead of shaking it by hand, if you had enough sand in your plastic tub to cover the bulb half way or more, then holding it on an inverted jitterbug sander would probably make short work of removing the air bubbles.
I like this idea. Or I could put it on Mom's lap when she's sitting in her recliner and turn on the massage function.
warehouse323 years ago
Great idea! I made one for my fiance as just a random gift and it came out better than i expected!
gneal3 years ago
That's so sweet! I wish I could come up with something sweet like that. Next project: making glass doors into concrete doors, right? ;)
bajablue3 years ago
Visions of red and blue concrete light bulbs are dancing through my head... this unique idea is one that modern/industrial Designers would die for!!!

This fabulous instructable also deserves it's own featured article on
dngbat3 years ago
Really cool project. I wonder if bleach or something inside the bulb and a small piece of rag shaken inside would be easier to clean inside. When i did Xmas balls years ago a small piece of rag and bleach inside the ball removed the paint to make them clear balls. Not sure about lightbulbs. Or get the clear glass type ones maybe? I will have to add this to the to try list!
joeashcraft3 years ago
Not to disencourage the DIY spirit, but if you're looking for a hook that actually holds up your coat, you might try the Linden Sweden Clever Hook. $10 on Amazon.

It uses two levers to clamp down on the item your hanging.
I've attempted this 3 times now and every time I try it, the cement is never hardened. I crack open the bulb and the cement is not cured. What is the problem. Is there no air getting to it?
check your mixture and be sure to leave it for at LEAST 2 to 4 days before breaking the glass.

I've made quite a few of these, using about 6 different types/styles of light bulbs and they all have come out looking beautiful. This has been one of the most Fun istructibles I've found and played with. Top Notch!

concrete takes 1-2 days to set. industry standard for aplying a working load is 7 days for quick set and 28 day for normal concrete.
"Is there no air getting to it?" Really? It's sealed in glass, lol.
Cubie2 Valche5 years ago
cement doesn't need air to dry... thats because it doesn't dry, it SETS. It will even set underwater... that's the beuty of it. I think you just need to wait longer- wait like a week and THEN crack it open.
I believe the amount of water you use, type of cement, and humidity of where you are all determine how fast it sets. I know there is a quick-set cement that my pool guy used to install a rail in Phoenix that set super quick in the dry air. They said it takes a lot longer to set up in Cali because it is more humid. Maybe try a quick set, don't use too much water, and wait longer if it is humid.
makijim4 years ago
Here's one my 5 year old daughter and I made. Thanks for the great Instructable!
cement bulb.jpg
What's that white thing under the bucket, but above the pliers in the picture on the front page? Looks like a very interesting object
bfk4 years ago
For years, I've been carefully working the threaded metal tips off burnt out bulbs to turn them into magic tricks (where you hold a bulb in your hand and it lights up). Your method is brilliant. I probably won't be making cement hangers anytime soon, but thanks for the labor-saving tip.
Spy_644 years ago
This would make a really cool door knob. (c;
Great idea - I will be making some of these.
In the UK the incentives to make everyone use energy efficient bulbs mean that ordinary bulbs like these are really cheap.

Buggerlugz4 years ago
if you hold the bulb filled with concrete in one hand and a electric sander (not a belt sander ) in the other and then place the bulb on the sander it will get all the air bubbles out
Wasagi4 years ago
I made one and installed it last night! It looks beautiful, and screwing it in just felt really natural. Haha

dacker4 years ago
Unless you are intentionally repurposing dead light bulbs, you could start with a clear bulb rather than a frosted bulb and skip the powdered clay removal step.

Instead of using masonry mortar, thin-set mortar used for wall and floor tile applications may be easier to get into the bulb and to remove more air bubbles.
whamodyne (author)  dacker4 years ago
When I started doing this, clear bulbs where 4 times the cost of the generic frosted bulb. Like that makes sense. I've come to the decision that it's worth the money to buy clear bulbs in bulk (still twice the cost) and save the time. However, not everyone out there is buying 100 bulbs at a time to fill them with concrete.

I've experimented with thin set mortar - the problem was that it's very, very sticky. It likes to stick to everything and makes quite the mess. I was spending a lot of time cleaning the thin set off the metal threads of the bulb. You want to do that when the mortar is still wet and the thin set was a true pain to do that with.

I've had more luck with sanded grout. You can thin it out more and have it be soupier and easier to pour into the bulb, still a bit harder to clean up than the straight mortar mix but no where near as bad as thin set. You just give up some of the gloss finish - the grout doesn't come out as glossy as the mortar mix. My colored bulbs are with a white sanded grout and then powdered concrete pigment is added.
You could try injecting the thinset using a large catheter tipped irrigation syringe. There like $5 on, and i use them for alot of things, like injecting expanding foam mix into holes, to reuse one after using the thinset in it, pull the pluger out and glean it, then use a pipe cleaner to clear the tip out, any thin bits of the mortar could be broken out by rapping the tip on the corner of the bench
Ah, that makes sense. The sticky nature of thin-set would be a PITA. I wonder if it could be squirted-in from a Zip-Loc bag as other suggested. (Probably not.)

I thought of grout too, but the high gloss finish is a strong attribute. I'm glad you did the experimentation so we don't have to.

On frosted vs. clear and the cost differential: It's always bugged me when products without something added cost more than the standard product. The classic for me is when bottled water cost more than soda from the same manufacturer. I never buy bottled water, but it's a common observation. No-salt products is another.

Regardless of the mixture, wrapping a bit of masking tape around the threads is probably easier than cleaning the threads.

I've got to do this project...!
Couldn't you leave the glass on the bulb? I thought that's what you were going to do when you started! The left-on glass might not be as fragile if there weren't bubbles in it that you could vibrate out like several people above said.

Awesome project, I might try it and try one with leaving the glass on if it's strong enough to resist breaking. (It should be if it's reinforced with concrete right? lol)
Wasagi4 years ago
Sweet! I just finished this, and in 72 hours, I will have a beautiful hook!
terribug5 years ago
I wonder if you could use burned-out bulbs?  Have you tried that?
Frogz terribug5 years ago
naw, you NEED to use a new light bulb or else it wont have an intact filiment
the use of the filiment?
to keep the thetons from disturbing the e-meters!
 LOL, Scientology is no more insane than all of the other religions out there :P.

I believe (!?)  - that so called religion, is almost unparalleled regarding insanity - LOL.
All religion is merely each cultures way of explaining our existence, and a way for man to never feel alone......Cool Light Bulbs though!!
I believe it is only surpassed by those celebrating their religious holiday today:  atheists.  Psalm 14:1  "Only the fool says in his heart, 'There is no God.'"  Happy Holidays, non-believers.
ARJOON terribug4 years ago
i totally agree with u. it is just a business and to gain leadership
 I guess that makes me a fool :P
Join the club. Muahahaha
 Don't even get me started on Christianity... 
Monitors will shatter.
Everyone is entitled to their opinions. 
Lol, yeah...
 I meant that in a totally serious way.
yes that would be the best after all you destroy it.
greggspen4 years ago
Have you tried using a comercial plasticizer additive to keep the mortar fluid and easier to deaerate while your filling the bulb?
You can get the same effect with a little washing up liquid, which is often used as a poor mans plasticiser.
deaerated concrete lightbulbs have no character.
everyone knows that
lol....funny !!
chamunks4 years ago
Apparently using Granulated Sugar to remove the white coating from the inside of the lightbulb should be sufficient.

Just hollow out an entrance to the bulb, add sugar, shake vigorously, empty.

I cant remember where I read it but I'm certain its on google somewhere.

Great ible *Favorited.
Very Cool! I'm going to make a few of these in different colors, and use the ones I like most as Walking stick knobs.
rodrique4 years ago
i'll try it, i'll use some old bathroom light fixtures to....just mount them at the front entry and screw in five bulbs...good for coat-rack

on the setting of concrete.....if bulb is clean,,,including no soap, should be no problem, colord concrete could be used,
mixing yr concrete with fine sand thet is rough cracked rather than round aggregate gives better bond, a small amount of Elmers carpentry glue, acts as a bonding agent......all concrete bonding agents are take-offs on this stuff.
the dryer the mix, the harder the set...thet is, the water cement ratio.
i'd make it pourable, with some Elmers for elasticity. and use a squeeze cake decorators do.
now if yr placing a lag screw, it will not stay in place with too wet a concrete..
i would gently tapp the sides , and bottem of the bulb....vibration lets the air out, also brings water to top....because fines settle.
then i would take a blastic bottle cap.punch a starter hole in the centre, screw in the lag bolt, and work it down, tapping the should fit right flush, wipe off excess and let set.........portland cement takes 28 days to set....but it will always draw moisture....because it is a fired calcium based never quits setting...the original portlands found in ancient diggings still is working.
i recommend using a sealer too''''i do this often, or a clear epoxy.
because it is one of the most mis-understod health hazards around.
sitting on cement, even walking on untreated floors....and living in cement base-ments thet have not been sealed, will draw the moisture and life force from the body....breathing in cement dust too is not right....but use gloves, the advice on glass breaking using heat sounds ok....but why not try hot water, boiling--then cold....i have not yet....i wish you well
it's too cold 4 me right now....gotta let this one wait
Lumpybat4 years ago
That could be used to make a cool door knob too
martzsam4 years ago
Next Step- Concrete compact florescent bulb.
I really want to try that now. I bet you could thread an armature around the twisty shape, to strengthen it.

It's a shame that those bulbs are mostly unsightly white plastic though.
You could always just take some acrylic paint to the plastic. Its amazing the effects you can do with that stuff. With the right job, you could make it look like metal or even wood... But be careful, like dombeef said below, there is mercury in those bulbs, which is only damaging when ingested, so wear gloves and a mask.
But there would be mercury in it
joselezcano4 years ago
After removing all the glass, the bulb was coated with varnish or something?
whamodyne (author)  joselezcano4 years ago
No - it comes out of the glass that glossy with no added coating. I will say not every bulb will be perfectly shiny every time. Each one is different, even when you do the exact same thing everytime. If your bulbs are not shiny enough for you, you can add some glossy concrete sealer or even a furniture wax if you want.
djfunkshun4 years ago
No need for soap and water just use some salt to get the white out. That's what meth smokers do!
Nice doorknob too.
brianaemma4 years ago
I've done a few concrete mold projects and I usually use vaseline to ease removal, but I will definately try the PAM teqnique now! Great Idea, Can't wait to try this project!
This is the project that first led me to instructables!
Ogredude4 years ago
Great instructable!  These are so awesome, and I can't wait for mine to cure so I can bust off the glass!

 I came up with a few refinements on technique for this, to make them easier to fill...

First off, I didn't worry so much about careful water measurements.  I just mixed up some concrete to the point where it didn't slump quickly, but would ooze if you left it for a minute or so, about the same consistency as the pictures show here.

I got tired of trying to direct teeny little blobs of concrete into the bulb with the spoon, and I sacrificed a kitchen funnel to the task.  I clipped all but about a quarter inch off the small end of the funnel, it perfectly fits into the base of the bulb and I can shove concrete into the bulb with a popsicle stick or the coffee stirrer.

I'm using a finish sander to vibrate all the bubbles out of the concrete.  I fill a bit, then hold the bulb on the finish sander for a few seconds, then fill some more.  My finish sander came with a soft pad intended for putting a buffing pad over, but I imagine any finish sander would work if you just put a washcloth on it instead of sandpaper.  I'll post back once my bulbs cure and let you know what the status of bubbles and gaps are.

Rather than fight to get the concrete around the lag bolt, I'm filling my bulbs to the top with concrete, then shoving the lag bolt in, wiggling it around, and vibrating the bulb on the finish sander to set it in place.  Then I clean up the metal screw part of the bulb with a wet rag.

Thanks for the inspiration, whamodyne!
 Not sure what I did wrong here...  instead of coming out glossy shiny like yours, mine are dull.  They still look pretty cool!

I'm wondering if it's the brand of mortar mix I used.  I couldn't find Qwikcrete anywhere, so I grabbed what Home Depot had, an 80-lb sack.

I also made one without a bolt in it, just for the sheer heck of having a concrete light bulb on my desk at work :)
Any fine concrete or mortar will produce the glossy results(haven't tried it with plaster, but it theoretically could work too,though wouldn't be as strong as concrete, even if oven dried after glass removal. But pbbly strong enough to hang a jacket on). The finer grain the better. also a light coat of cooking spray or wd-40 on the inside of the bulb helps, and also makes the glass easier to remove. on another note, using a large freezer type bag to mix it works great, and instead of multiple cups and funnels for clean-up, all you have to do is snip off 1 corner n squirt it in, pastry bag style. then there isn't much clean-up, just toss out the bag when done, and wipe down your work area.
illuminatis4 years ago
Great idea, although for i haven't tried this yet, I would think that a large heavy-duty freezer type bag, with one corner snipped off (like a makeshift pastry bag) would be a cleaner way to fill the bulb( and might reduce the amount of air bubbles)
Tinworm4 years ago
very cool indeed!
EvlPwnda4 years ago
Genius! I love this idea.. functional art win!
vxir5 years ago
Why crack the glass off?  Would it be fine for a doorknob or coat rack to just leave it there?  I would imagine that the crete inside would make it pretty tough... but I haven't tried this.

Also if you want to get the bulb glass without the screw on it, you can cut the glass neck of the bulb with a hacksaw -- the trick to stop the bulb from fracturing is to fill up a sink of water and cut it underwater.
wetnap vxir4 years ago
The glass would inevitably crack under use, its not worth the risk.
daggahead4 years ago
You could do this with spray foam insulation (Great Stuff), too.
rlindstrom4 years ago
two part epoxy resin should work pretty well for this project great project though a new use for an old product
I recently did a project with concrete that required me to mix small batches at a time (about 3 pounds per batch) and found that a heavy duty ziploc freezer bag was perfect for mixing. I mixed about 8 batches with out tearing the bag. I was using quickcrete with large aggregate in it and it worked great -several cups of mix, a splash of water and squish away! after the first batch the zip was covered in crud and would not seal but if I had taken the time to rinse it off before mixing the next batch it would have been fine.
drakesword4 years ago
If you made the mix a bit thinner (add more water) you could shake the bulb for a bit and get most of the air out easily
garyc4 years ago
I have made several of these to hang things on in my garage.Pretty cool! I coat the inside of the bulb with WD-40 before filling with mortar.Makes the glass a whole lot easier to remove.Thanks for the instructable!
zwebbo5 years ago
Hey cool stuff, I like the idear Check this out. I mixed the mortar mix with some acryl color for a present.
mamaof7 zwebbo4 years ago
I really like it with colour! You could do it to match any colour theme! :D
rbbiggs zwebbo4 years ago
Very cool
how did you do this? is this tile grout? how did you 'swirl' the color, as opposed to a solid color.
 I took a little bit of acrylic colors in the in the mortar mix. Mixed but only a little bit. So that you only get some colorfull strips. 
OR you can also but some color in the buble before you but the mortar mix inside.
IMPORTANT: the color need more time to geht dry. waiting 24h oder more.

ANTQNUT zwebbo5 years ago
EPIC! it kinda reminds me of a jaw breaker, but in a good way!
great job!

Cheers, Antqnut
Woah! This looks cool
that looks badass!
ANTQNUT zwebbo5 years ago
Cervantes4 years ago
Cool, great idea and imaginative. But I have to say it makes for an easy way to cast concrete projectiles for my sling. Much better than tennis balls, just need to gather up many old light bulbs, mix, por, set, crack, dry and sling.
rbbiggs4 years ago
You can buy the crystal clear Sylvania bulbs for a buck a piece.  Then you can skip the tooth brush cleaning part. 

I've been making a lot of these, been having a great time with it. Got 5 (3 different styles of bulb) on a oak 1x5 that I use for a coat hanger and they've been holding up Great (sorry for the pun). GREAT project! I'll post pics later if asked.
gcai_fwb5 years ago
What about using a funnel or the equivalent of a piping bag (used in decorating cakes - I suggest you DON'T use your wife's (-: ) - a heavy duty plastic bag with a corner cut should do it. Where I live milk comes in bags which would do the trick. Fill the bag and squish it in.     
rmccue5 years ago
This is awesome.  I was using some quickcrete for another project and remembered coming across this.  I am in the process of trying it now.  I have larger aggregate in my mix, but well see how it turns out. 

For the removal of the glass I was thinking of putting the bulb in the freezer, then putting it in a pot of boiling water.  Glass does not like this temperature change does it?  Any thoughts

rmccue rmccue5 years ago
I also added some red food coloring to the mix, we will see how that works out.
good one
Instead of mixing the concrete/mortar outside the bulb, it may be possible to partially fill the cleaned out bulb with water first, and then add powdered mix into it. I mix plaster this way (add powdered plaster to standing water), and there is no need for the physical act of mixing, the junk just has to get wet to work.

Glass Christmas ornaments would be neat!

Love the idea Whamodyne!
XWXAXDXEX5 years ago
OH YEAH!!! Great value ftw!
dinkin5 years ago
Strangely enough, I was able to pry up the metal piece at the bottom with just my thumbnail. Then I was able to get a hold of it with a set of vice grips. Popped right off. I'm only about halfway through and I think I'm actually just going to mount it to a board in a purchased fixture. Keep it around for function more than form. Renting an apartment doesn't really allow me to put the holes in my wall.
hi i made one of these and i it worked pretty well but i thought i needed a finishing touch so i painted it.

I'm not english, but this looks hella tight.

did u get that hella thing from south park?
Nope. I'm from Northern California, we say it all the time.
 thats mad cool. i have one friend who just started saying it because he watched a ton of california movies.
 "CARTMEN! Stop saying hella"
"But it's hella cool."
LOL, Southpark, gotta love it.
hahaha for sure. MANBEARPIG!
and imagination (spelling) land. when i twist my nipples they hurt! suck my balls kyle!
 haha true true :)

Oh awesome lightbulb by the way! i'll be making one ASAP! :D
lol he must be from Sacramento CA.... I been saying hella since 1983... long before south park.... yet if I say it anywhere else poeple trip lol
Go England!
Very good,it looks like the Union Jack.
Woah Love it!

did you ever consider the same concept with a different product?
Just that concrete can be such a pain, like you said its a science, where as you could replace it with grout, or durrabond, they are easier to mix just as strong, grout has a greater shrinking ratio, but durabond comes in a variety of drying times you can get durabond 90 that dries in 90minutes and doesn't shrink, and its dries like concrete, and the cool thing more so with grout because its white durabond is grey, but both can be couloured, with grout just add any colour of paint and mix it into the grout! So you could have a variety of colours, we use a u in colour in Canada.

dariokastro5 years ago
Otra manera de tener un artilujio bien lindo es rellenar las bombillas con concreto como vi unos de colores pero sin el tornillo.  cojer una tabla de madera cepillada bien terminadita  de unos 50 cms y pegar en ella  4 plafones de sobreponer atornillados , decorados y roscar los bombillos en ellas  quedan geniales en la entrada a la sala de casa para colgar los bolsos de la visita los abrigos sombreros etc.
DoubleM5 years ago
 so the glass isn't anymore on the lightbulb?
amandamany5 years ago
I think that lightbulbs are diferent here in Brazil, because i could'nt open any of them like you did.
omnivaal5 years ago
It'd make a nice gear knob in an old ute/pickup
 Finished mine :) its not very shinny but I still like it, vintage-ish :) 
 I just made one and can't wait for it to dryyyy!  : )
Great idea! I'm going to use mine as curtain holders!

I was skeptic at first, but this really is a cool idea.
Sirius Lock5 years ago
 I want to make a shift knob out of this.
minibah6 years ago
I think that would make for a cool door knob
Berkin minibah6 years ago
Yeah! How would you connect it in the door mechanism, though?

You would have to take a door knob, cut it by the wood of the door then cement that in instead of the bolt.

Hm, I'm not so sure that would work...
cement in the square rod instead of the screw.
Oh, ok.
Ocere5 years ago
You can also boil a pot of water, and then leave the base of the bulb in it until the glue softens, then you can just pull the entire screw assembly out of it!
phyzome Ocere5 years ago
Have you done this personally? I've been looking for a way to get the metal assembly off intact.
forlack5 years ago
Depending on your mix you could crack the bulb after 24 hours and then if you wanted extra strength keep it wet for 3-7days.  This will ensure that there is enough water for the cement to continue to hydrate.  Unless you are hanging some really heavy things though 24 hours is most likely sufficient.  3 day curing is about 50% 28 day curing strength.  7 days is 70% of 28 day curing.  These are just some rules of thumb.
ANTQNUT5 years ago
I've always liked this instructable. Very inventive.

Cheers, Antqnut
3n16m45 years ago
Have you tried rapidly heating and cooling the glass, to remove it? dropping a super-heated bulb into a bucket of ice water might eliminate a lot of the pain and time from the glass removal process.
Simple, smART and artistic for home stay... keep our earth green and smile...
Shane11636 years ago
wow cool.. almost looks like a planet.. or a moon!
That's no moon!
...It`s a space station!
it's a trap!!
nice ,i like it
Soupraok6 years ago
You should try to do this on a compact fluorescent
This link will show you how to take it apart, but be careful they contain mercury
im just wondering, but why is it so "dangerous" to play with mercury, yes I know the fumes are poisonous and everything, but my dad tells me stories of when he was in school, they, dare I use the term, stole mercury from the science lab and everyone on the bus was rolling it around in the bare hands WITHOUT masks or anything, so for just a drop of mercury I would just play with it!!! (yes, im 14)
well, mercury in better terms is a carcinogen (something that can cause cancer.) i don't know much about it (don't really care too much) but its better to play it safe, and just not touch it.
doesnt everything cause cancer now
Well duh, people are scared of cancer so they make up stuff to make you do stuff ie. They say that "blah blah" causes cancer so buy our "blah blah" to kill "blah blah"and you wont get cancer.
hot dogs is one
Everything causes cancer now because our life expectancy is so much longer than it used to be creating older more fragile bodies. Also our methods to detect have become more advanced.
Remember kids, 73% of statistics are made up...Probably including this one but hell.. who careS?
this is awesome i ran through the instructions and just finished off a perfect one. just has to set tho... oh, and the mercury? yea hold a droplet of it in ur hand for 2 hours and watch it all soak right through into you blood! yep ur skin is useless at protecting u from it. and it stuffs around with a lot of things! including mental, physical and defects in ur children... oh, and going even more off topic... most solder today contains very little to no lead or mercury. however the fumes are still poisonous.
Most solder these days, under the WEEE regulations, is silver based. That's why it is so expensive. Lead solder is banned, and they have never, as far as I know, used Mercury based ones. Mercury is dangerous when inhaled or in skin contact, or ingested. Even small amounts of some mercury compounds, particularly organic mercury, can be fatal in very small amounts. Methyl Mercury will go through latex, neoprene and silicone gloves, and your skin, in moments, and enter your bloodstream. Mercury is linked to death, as well as nerve and brain function problems, retardation, genetic defects and more. The metallic mercury you see when playing with it is relatively safe, however. Just play with it outside, well away from anyone's house or shed or anything, so if you spill it (and given the way it is ultraheavy and liquid, it is likely you will if it is in a tray or like) it won't do you any harm. Plus the fumes will blow away in the wind. DO NOT TOUCH IT! Yes, all our dad's did it as kids, but back then smoking was also thought to be good for you.
Solder isn't expensive?
I'm in Australia. Lead solder is still available and the most common is tin and copper. Silver solder is usually only used in electronics (because of the price).
sweet my lightbulbs came out perfect!! one broke but I found a type with a thicker neck!! i wonder could one add colour to it? i don't want to paint it cause i prefer the bare look??

ahh.. () mercury is mercury. no matter what form its in it does not belong in direct contact with your; air or skin. there is no way the mercury is going to "fume" its boiling tempt is up in the 300 c !! and the mercury is only vaporised and suspended under minus pressure in a halogen like argon or something. (in a fluro tube) which makes it bad cause if one breaks open you end up breathing it in and mercury does absorb through your skin!!
yes, they make special concrete stains, you can get them in powders, which really won't work here, or in sprays, which work after the concrete is cured. mostly they seem to come in sort of a reddish brown earth tone. it is often used on concrete floors, to make them more attractive. I recently saw it used along with a concrete stamp to make an entire driveway look like it was made with stones
Actually, mercury has a vapour pressure high enough that it will lead to the air inside a building having dangerous levels fairly quickly. However, if undisturbed it forms a skin and the evaporation slows down enough that it is safe with no more than a low level extractor system to change the air. Look into the mercury spinning mirrors that some places are using for star gazing. Once they have settled, they don't need breathing protection in the building.
ok this has gone on toooo long, Dont mess with mercury, its bad, if you do you will die. enough said.
yes thanks its enough. and what the hell is vapour pressure? ahah lol. i decided to paint my light bulbs but iv decided now that the bare mortar is way betta!
yeah... unless you u silver solder.
The phrase "mad as a hatter" comes from the liquid mercury and mercury fumes that hatmakers would breathe or absorb through their skin. The mercury exposure slowly drove them mad. Of course, if I remember correctly, mercury was a "cure" for VD, and those people didn't die immediately. The mercury exposure got 'em in the end, and right before was probably unpleasant, but breaking one lightbulb doesn't worry me when compared with the levels of exposure in the above applications. Getting exposed to mercury at all is a crapshoot, but the odds are in favor of you surviving a one-time exposure.
That was mercury compounds that were used in the hats that were toxic. And directly ingested mercury is very dangerous but skin contact, not really.
True, it depends on the precise compound and method of contact. But I think my thesis still stands, that the amunt and compound of mercury found in a CFL is not going to kill you (it might change the statistical likelihood of various illnesses, but not by much).
Mercury will also absorb into gold jewelry.
Jewellers keep their gold and other such expensive metals dissolved in mercury because most of the times the thief either doesn't know what it is or how to use it. So he gets caught.
Actually, Mercury used to be used by gold prospectors to dissolve the last little bit of gold out of their pans. Many of the streams in California are undrinkable because of that.
Um, I'm a jeweler, and no we don't... I have no idea where you heard that, but we're not stupid enough to keep mercury in our shops.
I've never heard of jewelers doing it as normal practice, but during WWII this was done with a Nobel Prize to keep it out of Nazi hands. I read about it in a TechRepublic Geek Trivia article one time.
Lol, I remember my Chemistry teacher telling us that Jewellers kept it this way to keep away from thieves.
Oh, cool. I didn't know that.
Now that's interesting...
Yeah skin contact is technically harmless but its just if mercury residue is on your hands and your finger gets cut or you eat a sandwich then it will go into your body.
Touching mercury isn't the issue (though that's not good). The biggest problem actually comes from dropping mercury into a carpet, then vacuuming the carpet and sending microscopic droplets of mercury into the air so everyone gets to inhale them. For years. The only way to get rid of then it is to remove the (toxic) carpet. And I would definitely wash my hands right after playing with it.
yea that reminds me when my dad used to suck on solder, he's still around and yet i don't suck on solder myself.
gharo5 years ago
my favorite things to do (i use plaster)but what i found it helpfull to vaccum the air out of the bulb i use my fridge compressor that i extracted ot of a used fridge found it on the street,also if u made the mix inside the bulb by fillng it with water then add concrete to saturation(without mixing) u get a marble surface with no bubles.
hi i madeone of these but it thought it needed a finishing touch,so i painted it.
jonnhye5 years ago
pffffffffff!!!!!!!!!!!!!estaria mejor hecho si le pones un led dentro!!!!!!!!
how about adding dye to the mortar to give it color?
sanidpv5 years ago
time consuming project , but it is nice
What effect would substituting the mortar mix with tile grout, as we have some left over from re-doing the floor. would this crack up easily, have a negative effect on sitting in large amounts, or wont work altogether. -thanks
whamodyne (author)  binglebeebop6 years ago
Tile Grout does well in the lightbulb. Be aware, it's more "sticky" than mortar so it likes to stick to the rim of the bulb and your fingers more than regular mortar would. It's not as sticky as the thin set mortar you use for tile (which was an ungodly mess the couple times I tried it) but still more sticky than mortar. I'm using a pure white grout as a base for most of my colored bulbs these days, it's cheaper and easier to find than a white mortar mix. Using a white base and adding pigment was the best way I found to get a consistent, bright color. Grout can also be mixed up wetter than mortar and not have the massive cavities and fall apart like the mortar would. However, the look is usually a bit more uniform than the mortar which has these wonderful color variations on the bulb, almost like granite. Mortar is also still the king of all the mixes I've tried for the shine you get straight out of the bulb. Grout will reflect well and give you a smooth surface, but doesn't have the glassy, polished look that mortar does.
if you do the tile grout bulb, and it doesnt turn out glossy like mortar would, could you spray several coats of varnish on it to get it glossy?
Of course, But do it lightly because Stalactites will form if you spray heavily. Also, don't set it down (Suspending could be a problem).
amg12935 years ago
WoW i´m definitly going to make one
ferdemci5 years ago
wow this is amazing!!!
charlynorte5 years ago
Muy bueno
Jouda Mann7 years ago
About the bubbles: Since you're working with a small piece, I would suggest getting a palm sander. Five bucks at any pawn shop, and it doesn't matter what condition it's in, as long as the motor runs. It works by rotating the head in very small circles, and vibrates nicely. Set it in a jig upside down, and turn it on when you need it. It has a dense foam pad on it, so it will cushion your work as well.
In my operative dental classes, when we are casting an arch of teeth from an impression, we place the plaster loaded impression on a vibrator table to shake the bubbles out of the plaster before it sets. I think the idea of using an orbital sander is good except that they go extremely fast when they are "unloaded". It might be better to find an old vibratory massager at a garage sale and use that (no, not the ones that are shaped like dongs!). You could probably make a vibrating table by bolting a motor to a piece of wood standing on springs. Attach an off-center weight to the motor shaft and include a speed controller. When the motor runs the weight will make the whole thing vibrate like the dickens.
The first thought was actually a 'real' vibrator when I was reading the 'get rid of the bubbles' part :). Any motor with something odd shaped stuck to the shaft vibrates, and should do the job?
And I would suggest not buying the dong shaped one at a garage sale!
hahahaha classic
hehe, touché!
OceanLady5 years ago
If you put it in a strong, clear plastic bag - like a freezer bag or something - the glass won't fly around so much. I used to have to break glass all the time for some of the crafts I did, and that always made it make less of a mess.
csavu5 years ago
I did it, but now i can't find no use to that since I don't want to put it on a wall.. lol
give me some ideas!!
karpoff5 years ago
OMG amazing!!!
big boy 7605 years ago
gee wiliceres!!!!!!! it works!!
airborne3256 years ago
I wonder if coating the inside of the bulb with something like oil before the pour would help the glass come off easier? I don't really know how hard it was to get the glass off in the first place though...
good idea. anyone know if an oil or jell put onto the glass would affect the concrete at all...
No, it won't affect the concrete at all, but it's a well-known cheap remedy for getting the mold of more easily.
You need to break the glass the concrete out. The glass should not stick to the concrete because there is not deformations or pores for the concrete to adhere to.
minerug5 years ago
What a *bright* idea (horrible joke)
to get all of the glass to come off from the metal base (or at least have it smooth), you could score the glass right at the base with a glass scorer/cutter. It will leave a nice smoth cut.
couldnt you also just desolder the end of the bulb? this would eliminate the need to "rip it off", pausibly causing the bulb to shatter.
dbp4285 years ago
Could you use moldable urethane to make a mold of ONE light bulb. Then just beak off the metal base and insert into the mold and fill that with concrete?
Just a thought, quicker way to remove glass. blow torch, gently heat but not too long. Bucket of cold water... Shouldn't crack the cement as long as you don't heat it too long. glass should shatter quite nicely though.
SLJ775 years ago
Maybe a piping bag would work to get the mortar into the bulb. Also wrapping the set bulb with a piece of cloth and tapping it on a concrete floor (like cracking a boiled egg) would reduce the danger of glass flying. The cloth and glass can then be wrapped for safe disposal.
matroska6 years ago
Stoping at step 2 and mixing with the "HIGH VOLTAGE POWER SUPPLY IN 5 MINS" Instructables to realize an evil scientist decoration to display in your secret underground lab filled of evil creations.
createchaos6 years ago
maybe an even better idea is to use bulbs that have already burned out. no sense in using a brand new bulb if you have some that are going to be trashed.... chandelier bulbs have interesting shapes (i'm looking up at mine)... grammar police can have a ball cutting up my post...
msdrpepper6 years ago
At the rate things are going, soon this will be a collectible - because there will be no incandescent bulbs.... if they get outlawed in favor of those fluorescent bulbs (CFL something for Compact fluorescent light bulbs), only outlaws will have incandescent bulbs. What I can't figure out is where do we get the 40 watt bulbs for the oven light in a fluorescent bulb?? etc. What about in our Lava Lamps that require a specific wattage bulb to generate a specific amount of heat, so that the wax goopy will "melt" at that temperature and do it's little flowing groove thang... whatever shall we do?
hmm. I wonder if this would work with CFL bulbs?
I wouldn't try myself because of the danger of inhaling any of the chemicals inside the bulb. Technically, you could though. If you do pull it off, I would love to see pictures.
Wow, that would be interesting but I'd suggest heavy duty face mask - if I understand this right, many of the CFL bulbs use mercury in them. Don't know how much but you don't want to inhale it or get it in eyes, etc. Beats me why the government is all in a twit to use CFL bulbs for low power consumption when they have mercury in them, yet they want you to get rid of mercury thermometers and so methinks they recycle the thermometer mercury to make the cfl bulbs? but that's just a thought that really isn't relevant to this most excellent project. I wonder how it would be if you could put in little flecks of like quarts or whatever inside the glass bulb so that the concrete comes around behind and beside it, just for extra "effect"?? or else use some of that paint kit to make it look like marble or granite etc once the concrete is set and the bulb has been broken carefully off of it?? it's an amazing project though!!
A mask will be of little benefit in protecting against gasses or vapours.
I mean "quartz" like the semi-precious stone, not quarts, like a quart of milk...haha sorrrry!! typing without my glasses and my hands are getting cold!
"I wouldn't try myself because of the danger of inhaling any of the chemicals inside the bulb." *gulps in regret* that reminds me of a story that my science teacher told me. during her freshman year in chemistry, her science teacher was going over lab safety and in particular the bit about not sniffing chemicals. the teacher claimed that his scent receptors had been damaged and that he was used to chemicals so if he sniffed something, that it would be okay. at that moment he takes a big whiff... and then goes into a coughing fit and eventually passes out. perhaps i should reconsider this notion...... :-)
no you should never try this their is mercury vapor witch can hurt your lungs
To be totally pedantic: - A capital N to begin the sentence, - There instead of their, - As between this and there (...try this as there is...) or - A comma in the same spot (...try this, there...) Incidentally, another thing you "should not try" with CFLs is break them while they are on. The vapour glows as it escapes, because although it is no longer contained inside the bulb, it is still under the influence of the electric field. It looks especially cool in a dark room. M'
Yes a witch can hurt your lungs (I end up spelling it like that too)
toolman8836 years ago
have you tried it with different types of bulbs ill post pictures later
u can use salt to empty the bulb quicker... instead of a toothbrush... U poor the salt in the bulb the swirl it around the bulb until the white stuff is completely gone then just poor it out!
I can verify this, it works quite well. It is rather difficult to get to the neck though, so the toothbrush would probably be helpful as well. Oh, and pour is spelled with a "u".
brokennye6 years ago
Sweet! I had an idea. My mom use to use this vibrating jewelry cleaner that would vibrate the grime off her rings. I am not sure if they still make them....but if you were to set the cup with the light bulb in it with it on a couple of days it would probably get a lot of those air bubbles out. Just a thought.
I used a Hitachi Magic Wand'," set on low. It works amazingly well. For many things.
acboothby6 years ago
That is so cool. A very nice piece of art!! I love it. How much does it way?
The regular-sized bulb ones I made weigh 11.6 ounces. I also made some slightly larger ones that weigh exactly 1 pound. Here they are with the glass still on.
neuromonkey6 years ago
I just made a batch of these, and I learned a cool trick in the process. I was finding it very slow & difficult to pack the mortar in around the lag bolt. By using a vibrator, I was able to fill the bulbs completely and drop the bolt in at the end. When the vibrator is applied, the mortar liquifies and the bolt sinks right in with little pressure applied. This is also great for centering and aligning the bolt--when the vibrator is in contact with the bulb, gentle pressure will cause the bolt to move slowly through mix. As soon as you pull the bulb away from the vibrator, the bolt remains stationary.
If you spray it with pam before you fill it with cement mix it will not stick to the bulb as much therefore you could leave it an extra day
DurkaDurka6 years ago
Hey, i have been admiring your project for quiet a while with hopes that i would get over to home depot sometime soon and grab a bag of concrete. well i finally did the other day and i combined your project with mine It look really cool and ill try and put some pictures up of it sometime soon
BFeely6 years ago
1thadeaus16 years ago
sry i comment so BUT i just thought of this. what if you used vegetable oil instead of water??? im just wondering if this would work...cuz mine wasn't much of a shine...idk if it would work...if someone tried it out and replied, that would be nice...thx.!>!>
1thadeaus16 years ago
how did urs stay so shiny? did u use extra water or something? less mortar mix?
dude u could market this
1thadeaus16 years ago
here a few pics of on how to make it better i think: crack the light bulb, but not taking the glass off...
with the bulb cracked, and not off of the bulb, leave it for another day and i think that it wont have as many "craters" in it.
Wicked Idea. Unfortunately, I had to use mortar mix because our town is too cheap to have small bags of cement. Worked fine. Although it heated up until it was quite hot then it decided to expand and crack the glass. I gave it a coat of varnish since it didn't have that same luster as cement does. Still worked fine.
DAND6 years ago
KineH6 years ago
Thanks for this interesting and comprehensive instructable! I followed the instructions - using 2 lightbulbs for the first assay. Unfortunately, I am disappointed to find that, after releasing the bulbs from their glass form, the finish is completely matt! The surface of the first bulb (when the mortar mix was fresh and at its wettest) is smooth (with some pits, as you anticipated), but the the glossy surface just isn't there. The second bulb (as expected) was filled with the 'leftover' mix (i.e., drier than preferable) during the last 5 minutes of optimal time, plus 5 minutes over. That one is grainy and matt. I used a refractory mortar mix (all that was available).
1thadeaus16 years ago
i just did it!!! it was so cool! it took only like 30 minutes to do it it is drying in my closet! thx! nice instructable!!!
rat36 years ago
Very Cool Project and I like the idea of using them as door knobs.. possibly on an outdoor gate, etc. IDEA: How about using a pastry tube to squeeze the concrete into the bulb.... I haven't tried it, but it should work. Anyway, thanks for the post:)
alysssalyn rat36 years ago
awesome doorknob idea O_O
Great instructable. Functional, and unique. One thought: could the mortar be mixed in a zipper bag, then dispensed likewise? Think deviled eggs ala Ziploc, or piping icing. So long as the lack of oxygen in the bag wouldn't have an effect on the mixture's reaction. Just a thought.
it looks like the moon. on the initial cracking you might try holding it inside a bag to prevent flying glass.
i want to start a band just so i can name it Concrete Lightbulb.
john52476 years ago
I have some white cement I used on a glass brick wall - I hope to get a white porcelain effect. I can get clear bulbs here in the UK - cuts out the powder cleaning bit. I'm thinking the white cement or plaster could be coloured or painted. THenks for a great idea and project. Also, I can think of lots of hollow lightbulb things now. Ship in a light bulb? Big white LED, battery in the screwcap. Unscrew the bulb in front of your freind and the light will stay on in your hand!! You might want to leave the white powder in to hide the LED and make sure there a big blob of glue where the solder main power connect used to be!
To those of us in the U.S.: You can get clear light bulbs as well. They are called appliance bulbs and are a little bit more expensive due to their ability to withstand high heat. I think it would be worth it to avoid the white-powder-clean-out step. If the local discount store doesn't have them, try a hardware store.
If the clear bulbs are the same price, go for it. But it's crazy to spend more on them when the powder if so easy to remove with a little salt shaken around inside.
ProjectZro Data6 years ago
or water...
ajmontag Data6 years ago
or maybe Thinset, a ceramic tile mortar (adhesive). that stuff is amazing.
Berkin6 years ago
Dude! You should try doing this to one of those energy-efficient spiral light bulbs!
gosub6 years ago
(removed by author or community request)
spork969 gosub6 years ago
If you paid attention, you would realize that the glass is removed before it hangs on the wall. If you are going to criticize an instructable, give at least one valid reason. Great instructable, cool idea!
artsy_grrl6 years ago
Have you tried adding dry concrete mix to the bulb, then pouring in the correct amount of water?
I would very much like to know about that too! Although you would have to know how much concrete you need exactly...
weezer13us6 years ago
a spray bottle works too. a couple sprays in the right place the white film is gone
Obediah6 years ago
Great idea, using a light bulb as a mold. What about Plaster of Paris? or Great Stuff Foam? I wonder how those would do?
djdavis Obediah6 years ago
Plaster of Paris dries way too fast or starts to set too fast and the Great Stuff expands too much and doesn't get hard enough.
djdavis6 years ago
There are a few ways to make this easier. First, when cleaning the powder out of the bulb you can simply flush it with water. The powder will wash right out. Second, you can use a funnel to get the mortar in the bulb rather than spoon it in. Third, you can put the bulb with the concrete in a plastic ziploc type bag and lightly tap the glass with a hammer or like metal object. This will prevent the glass from splattering into your eyes and keep your hands and fingers safe from being cut. Also clean up is non existent because all of the glass is already in a bag. Also, I tried plaster of paris. Not good. It isn't very easy to work with and sets too fast. Now as far as the bubbles in the bulb. If any of you men are married and your wife has a toy in the panty drawer, try holding it against the bulb for vibration. It's not quite as powerful as an orbital sander but should do the trick. I haven't tried it but it seems logical. Just don't get concrete on it. OW.
Bigev djdavis6 years ago
Why would you want to break the bulb? I see the light bulb as a form aspect, but doesn't the whole glass and metal base give it character and identification as a light bulb?
djdavis Bigev6 years ago
How would you like to hang something on the bulb and have the glass break later into your favorite jacket and little light bulb glass slivers in your carpet? It's a safety thing and you can get the concrete to shine like glass if you work with it and buff it out. Like concrete counter tops.
Bigev djdavis6 years ago
That a very valid point. I did not think of that.
C O O L ! ! ! i'm making a plaster mold to make these things from, and then just breaking the bulb and taking the metal part. i only use burnt out bulbs; reduces waste and means you don't kill perfectly good bulbs. i plan on replacing every bulb in my house with these, to freak out my parents...
dariggs307 years ago
Instead of using a toothbrush to clean the white stuff inside the bulb, try using some salt. Pour the salt into the end of the bulb. Plug end with your thumb and shake until the glass is clear. Pour the salt out when your done. If your careful you could reuse the salt again and again.
or, buy a clear light bulb ...
I was thinking the same thing. You can buy standard incandescent bulbs without that white frosting, which would eliminate a step.
Look at the pictures, he's using a clear one, you still should clean it...
uh what are you talking about? do you know what I mean by "clear" ?
Probably not.... XD Don't blame me! I'm stupid!
No, he's using a frosted white bulb.
bclark896 years ago
The best way to settle all of the air bubbles would be to vibrate the concrete mix itself. I would suggest something like a battery powered vibrating toothbrush stuck into the mix three or four times while filling the bulb. If the mix is over vibrated it will separate the water and sand out but if done for a short time it will do a great job the get the air out.
cbrown2226 years ago
you could skip the step where u have to clean the inside of the bulb out by just getting a clear bulb
daisyrock16 years ago
unique fence post finial? I love it! I'm not a crafty person but I so want to try this! Or maybe I'll just shoot over to Etsy....
this is really cool! I would consider making this to buying commercial hooks. It's a great way to reuse light bulbs.
deberickson6 years ago
This is probably the coolest idea I've seen! Thanks!!! You're the bomb!!!
whamodyne (author) 6 years ago

Thanks so much for all the great feedback. Over the last year I've still been filling light bulbs with concrete in various forms and trying different things. There are a number of things yet to try out, like various plasticizers and other additives to see how it changes the overall result. I've even run into a few people who have tried to make them themselves.

I do sell these in my Etsy store and local craft fairs. What started out as a simple contest entry has turned into a nice hobby that pays for itself, well at least some of the time.

To answer a few questions, I've tried cleaning out the white frosting inside the bulb with things like salt, rice, soapy water only, etc. I've found that scubbing it down with a toothbrush when it's dry, then washing it out with soapy water is the easiest way to get it nice and clear.

I've tried various mold release agents like oil, water based lubricants, etc. I know people who cast concrete in polyurethene molds use that stuff and it works for them, but with the glass, it just seems to gum it up a bit and I wasn't getting the high shine I know you can get without it. For folks making just one or two, having a hit or miss result might be OK but I'm trying for better production quality on a consistent basis. Tapping the bulb a lot with a hammer is still the fastest way to get the glass off the concrete. Even with all that and taking notes and everything, you never do know what you are going to get until you break open the glass.

Here's a photo of some of my recent experiments/inventory. Different colors, different cement based products. One suggestion, you probably don't want to use thin set mortar (for tile), that stuff was just way too sticky and got everywhere. The result was a more even finish without the cavities but man, it was a pain to work. And those cavities from the mortar mix? They add character.

Again, thanks for the great feedback.

- Ray Alderman aka Whamodyne
bulb selection 2 - small.jpg
I just did this with plaster, sans bolt. Looks pretty good, and is white/grey but should cure up to pure white. When it does I'll post a pic.
I hate to be a jerk...but it's s much fun... Has it not cured yet? It has only been eleven days since you poured them. Was it a total and utter failure? I think that you probably just forgot. Please remember. I looked forward to seeing your results...
rmccue6 years ago
Man this is great. I made a wooden shifter for my truck about a year ago but i think it is time for a concrete light bulb shifter. This sounds like a ton of fun
This could be a pretty neat rock for wall climbing for a nice, sturdy grip. Good job.
ewilhelm6 years ago
This project was mentioned in Popular Mechanics's 10 DIY Gifts for Friends and Family.
Big G6 years ago
Wow, thats pretty cool. :D I work in a lighting store, and I have seen many different kinds of bulbs that this could work on. Some of the smaller candelabra base lightbulbs, such as the G16.5 lightbulb would be perfect for a cabinet drawer pull. Or a T10 lightbulb, (better known as a piano lamp bulb) would be good for hanging a towel or something similar.

I have whole bin of used lightbulbs at work... I may have to try this. :D
I think that smaller bulbs would make great cabinet/drawer pulls. I wonder if resin or some other thin material would work better on a smaller bulb though. In that, how thin can you get the mortar and still have it cure in a reasonable time?
peepla6 years ago
we used to use lightbulbs as a pattern for paper mache puppets, you wrap it in plastic, coat it with the mush, let it dry, rack against something and shake the glass out into the trash, then paint the mold....crazy thing to do when you realize this was a project for a 3rd grade art class. however, lets go simpler, wrap a lightbulb with plastic ( i use glad twist and tie bags for everything...very convient) then wrap with duct tape to make a mold, carefully cut it up the middle, remove the bulb. use your medium to fill the mold (i have no access to concrete but there is always plaster of paris around here, use an extra piece of duct tape to seal the seam...the piece that seals the seam has a tiny bit folded over to form a 1/2 inch lip. when dry, pull the duct tape off the seam using the lip, then you can re-use the mold to make another one. I have a shoe last of both of my feet using this method. I even made a pair out of the duct tape molds by stuffing them with plastic bags and then the tape i used to seal the lip as I wanted them to be permanent. I figure that might help for those of us out here who are like me, a natural born clutz. mine isnt gonna look as good as yours, but i am gonna give it a try but i am thinking i want it to be pink or purple. cuz i like everything pink or purple. of course this method wouldnt have the base of the bulb on it, just the shape.
rford6 years ago
Vibrating the bulb full of concrete on an inverted random orbit sander should bubble all those air pockets to the surface.
senorpuma6 years ago
Everybody knows Thomas Edison invented the incandescent light bulb, but few realize he was also involved in the perfection of Portland cement at the turn of the century ( This lends your creation an added dimension of true artistic value beyond aesthetics. Evokes Duchamp.
Wario6 years ago
Nice, but cleaning the white powder on the inside could be easier, what I did was I pored salt into the bulb, put my thumb over the hole, and shook it till all the white powder was off the inside of the bulb, then I threw the salt away, and pored in water and soap to clean it clear.
nibbler1256 years ago
you could put this on the end of a stick and use it as a self defence weapon
Your defenitly one of those crazy medieval obsessed guys who make bows out of a stick and piece of string WANNABE-RUNESCAPE-MEDIEVAL-WILDERNESS-LIVINGIN1300S-GUY
im not rly a midevel guy i just like homemade weapons
Lol thats cool then.. Check my airgun instructable. If you make homemade weapons spud guns are for you lol
I love these. They are so fabulous and I am going to make a wall art sculpture using them. Have you tried making them with the low energy curly spiral lighgt bulbs? may be more difficult but still great looking!
BeanGolem6 years ago
If you want an array of bulb-hooks, you could use a standard hex bolt instead of a lag bolt, and mount several to a board, which would then be mounted to the wall studs. It might also be cool to use some cement die to get wacky colors. just a thought.
Fatvod6 years ago
This reminds me of the globe hang challange in NINJA WARRIOR!!!! Can I build my own course with these? HELL YES!
haha, yea, it does thats show is pretty kewl
soad22 Fatvod6 years ago
lol, they do look like them
love it, I'm having a go!
kraM6 years ago
oh and a pair of sissors works prety good for getting the metal contact and the glass insulator off the bottem & for breaking / removing the fillament
kraM6 years ago
hello here's a bit of advice ( if your using lightbulb's with the white powder ) use table salt to get the powder out all you have to do is fill it with about a 1/4 cup and shake / swirl the light bulb so that wat you dont break the lightbulb if you slip with the tooth brush, that and it kindof looks cool i use this method for other applications so in my experience it works pretty well
osgeld6 years ago
what if you used a porcelain socket screwed to your wall, a hole in the middle for the lag bolt, and a washer and whatnot
this stuff works much better than concrete for small pours it also is not pourious
also use a vibratory sander (no sandpaper) to screed the concrete to get the bubbles (voids)out of it
very cool as well as useful ,nice presention
sir_h_c6 years ago
how about using the smaller flame shape bulbs and smaller bolts? maybe flame bulbs with a standard base?
puffyfluff6 years ago
That is a great idea. I just poured one.
ReddySV6 years ago
Impressive. Thanks.
How about going to the craft supply store and getting small glass "jewels" to add to the mix?
Arnseb6 years ago
really nice Instructable!...can't wait to try!
Redgerr6 years ago
that is SWEET!!! i really like them :O i dont think i will ever make one because it doesnt fit, but its super cool and i love the idea :O
codester6 years ago
You should paint it.
They make colorings for concrete, and if you look at his etsy page, he does use them for some.
I've been wanting these for a while...and I finally made them today! I went through the house and found a few lamps that hadn't been switched to CFL yet. It took me 5 bulbs, but I now have 3 hardening out in the garage. I'll post pictures when they're done.
Here they are! I'll be putting them up later today. They're the color they are, because I had just washed them off (to get remaining glass off)
Lftndbt6 years ago
This is about the fourth time I have read through this Ible.

I still find the application of the globe truley... functionally, aesthetically brillant!!

Great work my friend...

Feel free to add it to my group.
I challenge you to make one out of one of them energy saver lightbulbs, the ones with 3 curved prong-like things... now THAT would be cool.

Not that this one isn't cool anyway
HEY! don't tempt me!
Go ooonnnn, it would be really cool, and make an instructable with it!
yea, I should, but I don't really have access to concrete (seeing as I'm only 14) and my parent's wouldn't let me tear apart one of those bulbs anyway, they cost too much, I should have saved the one my neihgbor had that was flickering (which isn't good for a fluorescent I think) but oh well, I'll try!
Don't break open a CFL they have mercury in them which cause problems later in life.
I second that emotion. The last thing we need is to expose humanity and the environment to more carcinogenic materials.
Ah yes, let's save the environment by using less electric, by putting small high temperature glass envelopes full of mercury in our houses. Fab! I'll take 10.
1. If you were planning on throwing them against a wall it might be a problem, but the US does have a recycling program for CFLs. CFL Recycling

2. If you don't like the idea period, you could always shell out a few bones and pick up a LED bulb.
and I was just looking at the "take apart a compact fluorescent bulb" (or something like that) and the spirals wouldn't be strong enough unless you reinforced it somehow and I personally don't have the supplies, sorry!
Really, really cool! Looks....... Futuristic. Well done!
hassi7 years ago
Lovin' it...These'd be fantastic door knobs too...
bustedit hassi6 years ago
Definitely. I'd rather as a knob so I can feel its cool surface more often, ya know?
_soapy_ hassi6 years ago
Awesome idea! I'm going to try making some smaller ones from low voltage, or other smaller bulbs, and do a nice rack. To get a fine surface finish, you can vibrate the bulb a bit, so it settles well. Add a little more water to help.
a paint shaker on very very low works a treat! i found one small air bubble!
LinuxH4x0r6 years ago
I made one, but I left the glass on. I'm going to use it for the shifter on my electric car I'm converting
orbitup6 years ago
I made some of these (using this Instructable) for my mother for Christmas. She is impossible to shop for, but this really impressed her. I should have thanked you earlier but... butter late than never. Thank you.
Duke Steele6 years ago
Would spraying Pam cooking oil into the bulb act as a release? I've seen many concrete forms and they are all coated with oil so the form will come apart easy and the concrete won't stick to them. Either way, this is a great idea
rizkyw6 years ago
what's a stud?
A male horse bred for, well, breeding.
Sorry, I couldn't resist.
yeah i know that but i think he was talking about a different kind of stud in the instructable? the type on walls apparently?
whitish rizkyw6 years ago
JonG6 years ago
Awesome, good job!
inquisitive6 years ago
Wicked! Love it!
pyro136 years ago
This is great, you need to get a patent on these!!!
the4est6 years ago
thats pretty cool! you should try to make a candle in the shape of a lightbulb by doing this!
These are really beautiful... not at all what I imagined the concrete to look like when the glass was removed. These remind me of the polished marble and exotic stone orbs and eggs that you find in rock shops. Really well done instructable -
reniccicobb6 years ago
When I saw these on Etsy I thought they were great but would be easy to replicate. Now that I see all of the steps layed out, I really appreciate your craftsmanship. Great instructable and great product.
srhadaham7 years ago
any reason u couldn't just leave the glass on. I mean unless it falls out of the wall(not very likely) what's it really gonna hurt to leave it on?
Because it is so thin and brittle. It's a millimeter or so thick, not like a window pane. Under normal use, it has a vacuum inside which adds to the strength due to the shape. When full of concrete, this is obviously missing.
wilsonater7 years ago
Well, they didn't work. =(. but, no fear, I bought some more bulbs and filled them with cement instead of concrete, these WILL work.
The issue there is that the cement will flake and shatter over time. Without a bit of sand to give it some elasticity, your results might not be so great. I'd suggest using an acid washed "white" sand, rather than a sharp red sand for this. I'm going to give it a shot at some point. Perhaps a small rack of the lower voltage lightbulbs would be neat, with some smaller lag bolts, or perhaps a longer screw that has had the head flattened and bent.
neopirater7 years ago
How does it stay glossy after the bulb is removed?
whamodyne (author)  neopirater7 years ago
It's the mortar mix itself. I didn't shine it up or anything, that's just how it comes out of the bulb. One of the reasons I'm using the mortar/sand mix is because it does this. Concrete in general can be polished to a high gloss but normally you have to use diamond sanding pads. However if you use a glass mold you don't need to.
Sorry, but I believe that you are saying a lie. That shine is of the glass BEFORE OF BREAKING IT. No concrete shines in that way. Also, if the surface is of concrete, the reflections should show the pits.
Your wrong. Concrete can shine like that, look at this floor for example:
If you like believe, it's YOUR choice. I looked any concrete floor relatively shining. But this is because there is also a plastic coat. For me, the shine of the concrete NEVER is so brigth as the last photo of this instructable.
concrete CAN shine that way, if it has a perfectly smooth surface as a mold. also, it's possible this concrete mix has polymer addetives in it, to enhance workability. this helps too. and last- you cannot see any of the writing of the glass bulb ("100W", "made in China", etc.) from any angle. so the glass isn't there. i think you owe someone an appology...
1) The letters (100 W, etc) they can be erased easily of the glass. 2) I DON'T BELIEVE that the concrete's shine can end up being as that of the glass. 3) I DON'T BELIEVE that I should apologize to anybody for what I believe neither for what I think. I don't know how it is in other countries, but in mine at least, it is not this way.
1) true, but i don't think this guy is going out of his way to cheat everyone here. this thing is starting to sound a bit crazy... 2) i've seen it in high-strength concrete mixtures. it's quite common. concrete can be shiny if it has enough water. most concrete objects you see in everyday life are too dry, because water evaporates before it has a chance to chemically bond with the cement molecules. in this glass bulb - water can not evaporate. so the concrete object does not develop a matte dry layer on the outside. 3) appology has to do with the phrase you used " I believe that you are saying a lie". don't know how it is in YOUR language - in English this is NOT a complement... (in some languages it sounds ok, but not in american english. BTW, try saing something like that in Arabic - you probably won't live long enough to even TRY to appologize...)
Regrettably I don't speak neither I understand the English language as me wanted. But I see that many persons habitually speak it but they write it worse than me. I don't say this for you neither for wamodyne Regarding my hypothetical order of excuses, it doesn't correspond because I took care very well of saying "I BELIEVE that you are SAYING a lie" that which is completely different -in USA like in the China- of "you are a liar", that which yes it is an insult and it is very far from my spirit. One can say a lie without being a liar. Regarding concrete's shine, it is not as that of the glass. I have seen it, I am 62 years old, not a child. If you want to send me a concrete piece that shines as the glass (one or two grams, it is not necessary more) and it is as you say, I will apologize to whamodyne, to you and the whole community of Instructables. I can give you my address in Argentina to your personal mail. Thanks for your interest in my opinion.
trying to be nice, but someone is really sending some big paranoid accusations against a bunch of people. i BELIEVE aliens made the lightbulb coathook. and i believe they lied about where it came from.
neuralstatic, forgive me but my English is not enough to understand subtleties. If you refer to me when you say that "someone is really sending some big paranoid accusations against a bunch of people", I suggest you reread carefully what I have written. I have not offended anybody, I have simply expressed my opinion regarding the shine of the glass that some persons seeks to attribute to the concrete.
OK-where I come from (all over the U.S.), when you say you don't believe what someone says, you are saying they speak an untruth (lie). You are, in effect, calling them a liar. In addition, you straight up stated " I believe you are saying a lie" In my book, this is one of the most dire insults one can make. The lesson here is: be very careful how you state your misgivings/disbeliefs. You probably should have said something like " I find it hard to believe you can get that kind of finish from concrete, could you please explain in more detail?" If you aren't comfortable with American customs, "insults", or the language in general, tread lightly, please. You also might learn more about concrete, cement, and mortar finishes before trying to come across as some kind of expert. BTW, Whamodyne- pretty cool. It would be fun to see an entire wall peppered with common objects done like this and maybe painted as kind of a semi-functional artwork.
i've heard "i don't believe that" as a simple statement of disbelief berfore... a few times, actually. much like "no way"... that doesn't literally mean that there's no way that something's happened... it's just more of a "wow"... i dunno if this's how rimar meant it, but it might be.
You may just not have seen concrete cure under these conditions. If concretes surface is mostly exposed to the air while cureing (drying) it will not be very smooth at all. However four differant things I know of from many years of working with concrete for a living can make it have a very high gloss shine. Generaly you don't want it to be smooth and shiny if it's going to be walked on out side for example. It would be very dangerous when wet or in the winter. But in some aplications it's desirable to have it shine, and thats where altering the process of making the concrete slightly can produce startling results!! 1) as stated before by others if it is allowed to cure slowly in an environment where it stays wet for a long time it tends to have a smoother surface. Not shiny but smooth. 2) if you add to that "pressure" against a smooth surface it causes air bubbles to either be pressed away from the exteriour surfaces and/or back into the mass of the concrete untill it cures. Or if it takes long enough to cure the bubbles will excape to wherever you have left an opening for the evaporative curing process. The combination of these two first steps (slow wet cure and pressure against a smooth surface) will make the concrete look like polished stone. It will be super glossy with no added effort! 3) On a concrete floor you can use power tools of several kinds to grind down the surface slightly and you will end up with very simular results. It won't stay that way unless you seal it as you mentioned before. I did a floor in a resturant once where as the truck poured the concrete and we were dragging and evening it out with hoes we sprinkled several earth tone pigments on it randomly so the would be partialy mixed in. Then before it was stiff we scored it using some scrap wood moldings so it had a tile pattern. Then when it was 'green' (stiff enough to walk on with out hurting it but not dry) we took a floor buffer used for polishing waxed floors and a big sand paper disk and polished it while still green. It looks like beutifull imported marble, a cream color with differant shades of brown, tan and grey streaks. Very beutiful. It kept that high gloss for about three years with no wax, polyurathane etc. However after that time it did become dull and needed to be re-sanded and at that point it was sealed with clear polyurathane. The owner should of had it done to begin with. 4) You can also get a high gloss surface by altering the chemistry of the concrete mix. There are several differant additives that can be added that slow the curing process way down. The longer it takes to cure the smoother it will end up... and the harder and more dense the finished concrete will be. My employer did a footing for a factory that was going to have huge injection molded plastics presses that were 100's of tons in weight, so regular concrete would not work because it could not take that kind of load. We used "fero-create" insted with additives to slow the curing way down. I was new at the job then and when after cureing for two weeks with huge sheets of plastic on it I was suprised to see that not only were there areas of it that were as smooth as glass but it had blue color to it due to a chemical reaction between the iron powder (the fero in fero-create)and the concrete. Very nice floor that stays way smoother then regular concrete perminantly. And it's about the hardest stuff I've ever delt with. It took me more then 8 hours to bust up with a sledge hammer a 3' by 5' by 3" thick slab of it made from some leftover from a job that used to be by the back door so I could put an addition on the house. It was like trying to bust into a bank vault with a ballpeen hammer! LOL :-) Under MOST conditions concrete is dull and has a rough finish but in my experiance there are some realy easy ways to make it turn out this smooth. Those methods may just not be common practice in some places. In fact there not realy that common here either but it can be done and it's not that hard. Regards, Skon
Skon, I thank you a lot your interesting explanations about the cement and their possibilities. I never denied that it shines, what I said was that it doesn't shine as much as the glass. I have received so many critics for my opinion that I will have to make the test. I suppose that one week should be enough time to obtain the shine that wamodyne claims. Analyzing the first picture of the instructive minutely, it gives me the impression that the glass of the lamp is still present. Don't leave any step where the metallic part begins.
I live in the united states and have several planters and "bowls" that I made using glass and plastic as molds and as luck would have it, they came out as shiney and as smooth as glass and perfectly smooth other than where air bubbles surfaced. They look like high end polished stoneware! My friends were amazed, as were I, and I realized I have lived long enough to learn that I haven't seen everything YET and that there are things left to discover. Judging by your avatar I'd wager those are lessons you should have learned 30 years ago or more. Instead of fighting over things you haven't seen personally, maybe you should just keep quiet. No one really cares what you think until you try and call someone a liar.
Woah. Leaving off the last three sentences might have been better.
I repeat you what I have said to others: I HAVE NOT CALLED LIAR TO ANYBODY. Learn how to read, and don't invent about my words, or the liar then you are. I see that there are a lot of people that doesn't tolerate that somebody who they consider inferior (I do'nt live in the united states) makes them notice their errors or lies.
concrete does shine. i built a subwoofer speaker cabinet coffee table out of concrete some years ago (circa 1975). since i was mixing the concrete and making it in my living room on chocolate brown carpet, i used plastic to cover the floor when i was making the molds. the side next to the plastic was a perfectly smooth and shiny on the plastic side side. it was a very unexpected bonus to have the cabinet so shiny and smooth. and NO, i did not get a smidgen of it on the carpet.
I've made concrete molded in glass containers, and it DOES shine like that. This is not a lie.
Sorry rimar, when concrete is molded in a mold with a very smooth surface the portion of the concrete which crystalize do so without the introduction of imperfections allowed in other molding situations. Air, wood, and even plastic allow for some roughness to form during the crystalization process that is what makes concrete hard and solid. When this process happens against glass it encourages a smoothness not attainable by other means except diamond polishing. "Skeptisizm is fine and much needed to avoid being decieved, but not so useful when it blinds one to truth." Nathan Onefox, 1927-2006
Thanks, I agree wiht you about skepticism. Perhaps I was too much hurried in judging.
wtf are you talking about? concrete floors dont have to be covered in plastic to be shiny.
so did you maybe think of doing this to prove everyone wrong even in a smooth plastic bottle there os good shine and having made a pint o' concrete I know it can be done
If there was glass covering the concrete, it would likely have a Milky appearance from the whitish from the type of bulb that the creator used ( you can see the contrast here: ). Concrete can polish up like granite and marble... maybe your local sands/silts interfere with this process. But the mold makes polishing unnecessary.

But I will tell you highly polished or molded concrete is mad-sexy.
The wall of my basement workshop/lair is concrete. You can see wrinkles in it from the plastic sheet that lined the mold. Given how incredibly smooth it is from just plastic, I have no doubt that glass from a glass mold would be that shiny. Concrete takes on the texture of the mold; that's why you can see wood grain in a lot of concrete bridges and buildings. It's from the plywood forms that are used to pour it. Also, if you look at a profile image of step six, there is a slight gap between the metal base and the concrete. If you look at a lightbulb, you can see that the glass has no gap between it and the base. The glass must have been removed. If someone had a picture of a concrete lightbulb with only some of the glass removed, that would be helpful evidence.
whamodyne (author)  rimar20007 years ago
Well then, the only thing I can say is buy it. It is for sale at:

If it's not that shiny in person, I'll refund your money after you ship it back.
Whamodyne, I live in Argentina. For U$S 12.95 I can manufacture some 30 of those.
THen do it, and stop calling people liars.
I request you that rereads what I wrote. I didn't call liar to anybody. Up to now. You are here saying a lie, and that doesn't mean you are a liar. I possibly make the test, when I have free a while, to demonstrate to myself if I am right or not.
So, by your logic I can kill someone and not be a killer? I can steal and not be a thief? Groovy! I'm going to go have sex with hundreds of people, charge them $150 a pop and not be a prostitute. I like where you're coming from. BTW, you'd probably have the time to make those some 30 if you'd just be a man and say you misspoke. In other words: Put up or shut up.
sanity eBrain7 years ago
Sounds fair enough. What can I get for $50? :)
eBrain sanity7 years ago
Well ... for a measly $50 ... you get this reply. But you can read it over and over and over again by the light of Whamodyne's concrete bulb. Do enjoy. ;)
wrong-look at step 6 picture 2 it shows what it looks like with the glass on it and step 6 picture 9 you can see the mark there left by an airbubble which has NO glass on it and its still shiny
Great idea, I own a concrete countertop company and yes concrete can come out of a mold with a really nice shine. I like the bug holes they give the concrete a rustic look. Many of my customers have me leave them on the sides but for the top you always grout the holes with a cement slurry. Also try mixing in some colored glass chips.
eukara6 years ago
love this ible! very cool! only one suggested alteration; instead of using a white light bulb, and cleaning out all the white powder, just try a clear bulb instead
Soupraok6 years ago
Good job. This is a great idea.
DWRead6 years ago
Another way to clean the inside of the bulb is to put a spoonful of raw rice in with the water and detergent,. Move the bulb with a circular motion so the rice swirls around and scrubs the inside surface. Works with flower vases, too.
DWRead6 years ago
I can imagine this in a store--not as an item for sale, but as fixtures used in trendy stores in Soho (New York City).
camb006 years ago
im going to put 1 in my roof lol how ironic
camb006 years ago
i have a cool idea fill the bulb up with water then add some yeast then freeze it then epoxey the top the watch micro organisms grow like sea monkeys
Sandisk1duo6 years ago
wow.... 10lb of concrete for $2 i thought iw would be like $10
bentply6 years ago
Thanks. Very smart. Love the effect of cast mortar in glass.
jason-25907 years ago
On another where they showed you how to make a lightbulb vaporizer they just put salt in the bulb and swirled it around and it cleaned the inside and it went clear. Try this instead of using a toothbrush. Good instructable by the way.
wilsonater7 years ago
Hi, I've just made my own concrete light bulb wall pegs. I went to a local store and bought 2 lightbulbs for £0.44, (about 20 US cents). I hollowed them out and followed the instructions but the concrete I used had A LOT of small stones in it so I don't know if it will fill all around the sides of the bulb and so it might not work. Anyway, wish me luck and I hope to make another post in about 3 days to tell you if it has worked. =)
1up7 years ago
Nice! Great Instructable, neat product! Now all that's left to do is try it with a compact florescent. :P
jbcasino7 years ago
these are great!! i went a couple of steps further...using my dremel to open up the bulbs. masking tape the bottom of bulb and rattle can any color you want. have also made a beautiful vanity using 3 bulbs painted white and hand painted scenes on the bulbs (very cool and unique).
Send me a free bulb if this helps as I think it will. 1. After cleaning the interior of the glass globe, spry with silicone, drain and dry before adding concrete - Also try that rain away stuff they sell for repelling rainwater on auto windshields. 2. Watch a French Pastry Chef embellish a creation with a pastry bag and see if your mixture wouldn't work as well as fudge mix. Also, since you have 25 minutes "working time, might it do to hold off filling the globe with concrete for a few extra minutes in the hopes that the all-important moisture would help filling and "de-bubbling" the mix? 3. Try the larger round globe bulbs usd in bathroom fixtures (fat coat/hat hangers, or stubby table legs? Nice project, well done instructable - thanks for sharing.
dfc8497 years ago
this is awesome! and this caught my eye - you still have a 9.6C skil drill mine died a few years ago and got an 18V B&D
deephidden7 years ago
You can put some salt in it and shake it around instead of having to scrub off the white from the bulb. A little fast and a little easier.
Hey, that's a nice trick! I've noticed that when a filament burns out it will sometimes scratch away the coating. Hadn't quite made the logical leap. :-)
Davenchi1237 years ago
that is bad ass dude
Very pretty! It has a nice almost-industrial look :) Plus, your instructable comes with the added entertainment value of Crazy Argumentative Commenter and Friends!
callmeshane7 years ago
a second comment... I used to work in assorted foundries... and some castings are OK fairly rough... but some castings (hot liquid met