Step 3: Mix up the Concrete

This is the part that's more art than science. I've found that in the small batches this project calls for, it's very easy to add too much or too little water to the mix. When you are mixing an entire sixty pound bag of concrete, being off a teaspoon on the water doesn't matter that much. When you are mixing up just a cup of concrete, that teaspoon starts to matter.

Mortar mix when cured in a glass mold like we are using gives a very nice gloss surface. The lower the amount of water you use, the smoother and like glass the surface is, and the stronger the resulting cured concrete is. However, the lower the amount of water you use, the harder it is to have it fill in the gaps on the sides and it leaves lots of holes and divots. It's getting the mix liquid enough to spread out but not too liquid that it looses it's strength is one of the issues on the water to dry mix ratio. Finding the correct compromise between these two issues is really a matter of practice and personal taste, I would suggest you play around with it in multiple bulbs if you are interested in getting the best result you can.

The ratio I've found works well is about 1.25 cups of the mortar mix and a hair under four tablespoons of water. So measure out a little under four tablespoons of water and put that into your plastic tub. This is more mortar mix than you need to fill a lightbulb, but there is always some spillage and trying to reduce the amount means even more accuracy on the water measurement. This is a good place to start.

Slowly mix in the mortar mix a little at a time. Let a little bit get wet, then a little more, then a little more while stiring the hole thing. It's a bit like making biscuit dough at this level, but your pouring the dry into the wet instead of the other way around. The consistency should be good enough that the mortar mix wants to stick together in one large clump, but it isn't sopping wet. If you feel you need to add more water or mortar mix to get it correct, then go for it. Just do it a little bit at a time. A small amount of either material make a large impact at this point.

Once it's at a consistency you like, keep stirring nice and slow for a few minutes. You want everything to be throughly wetted as much as possible.

Important! At this moment the clock starts and you have 30 to 45 minutes to finish the lightbulb before the mortar mix starts to harden up.

Once you have throughly mixed up the mortar mix, bring out the lightbulb and start filling it up.
Could you use blown bulbs instead of using a new bulb
<p>Just a little late to the game......</p><p>Haven't put the bolt in yet, but you get the idea.</p><p>How much would you pay for one like this??</p><p>Let me know what you think...yes, no, maybe so?</p>
<p>Is that resin? Because I love the colour of it - almost honey-esque!</p>
<p>Yes, it is resin. To get this golden color I had to experiment with the resin:hardener ratios. I had done a clear one in the proper ratios as per manufacturers instructions, but it doesn't have nearly the same visual appeal to it.</p>
<p>How did you fill it while keeping the stem intact? Did you make a small hole within the stem only? And one last question, is this with the glass still on? it's an absolutely gorgeous piece.</p>
<p>Thank you.</p><p>No glass on there at all, solid resin. Extremely difficult to make, but will provide an Instructable shortly....</p>
Have you done an instructable for these resin bulbs yet? I wou love to do them
<p>Yes I did.</p><p>Type:</p><p> &quot;The Ultimate Light Bulb Wall Hook&quot; into the search area.</p>
Fill the bulb about halfway with salt, put your finger over the opening and shake. All of the powder coating the inside will be removed in about 5 seconds, no toothbrush needed.
<p>That looks so totally awesome. Sadly, we can't buy edison light bulbs anymore. :(</p>
<p>This is so cool! I love this idea, and I've been really into concrete projects lately. It's a cheap hobby, and it results in modern but useful stuff like this. I do love the resin/honeycomb colored bulb shown below, too. There are too many things I want to do, haha. www.mastercutconcrete.com.au</p>
<p>Looking amazing :D Very fun idea !</p>
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.
<p>Made my day :D</p>
You can clean the lightbulb with salt. Pour some salt into the lightbulb and shake it around. The salt removes the white powder
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
nice <br>
Benny8025,what is gypsum? Plaster of paris? I know it's found in drywall.<br>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 <br>Winter entails :<br>Sleeveless t shirts<br>short pants <br>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. &gt;_&lt;
sorry to hear that...I am looking at 75 degree days but 40 degree nights..could use some rain...drive the tourists away and make beach parking easier..Perhaps you will get the snow you need
closet door handles<br>
yes..... you just added more brilliance to already existing brilliance... ☺☺☺☺☺☺
<p>AWESOME! :0)</p><p>I need to make 1...or 3....dozen. :0)</p><p>these would make great stocking stuffers for Christmas!! Birthday presents! I can think of a million &amp; one reasons for giving as gifts!</p><p>TY for sharing. :0)</p><p>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?</p><p>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.</p><p>Granted, you still have minute particles of glass to deal with, but as you said, a shop brush should take care of that.</p>
<p>Nice Idea!!!</p><p>In one side I've been thinking on how to recycle soiled light bulbs but I didn't find it any easy myself.</p><p>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.</p><p>Good luck selling them!!</p>
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. <br><br>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. <br><br>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. <br><br>Does anyone know how to safely dismantle a cfl? I think one of those would be fun to try as a cast.<br><br>happy casting<br>
Instead of a toothbrush &amp; 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 &amp; shake it it will clear it right up!
<p>Cool!</p><p>the way we go through lightbulbs around here, I won't have to buy any...</p><p>Very nicely written, very educational,....can't wait to make a few(dozen) myself. :P</p>
<p>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.</p>
<p>one question, how do i make it?</p>
<p>one question, how do i make it?</p>
<p>My mind was blown by it for a couple of seconds, but the longer I looked, the more it seemed like a concrete doorknob. Still, it's a really cool idea. I'd definitely like to try it this summer. Thiago | &lt;a href='http://www.sceniconcepts.com/' &gt;http://www.sceniconcepts.com/&lt;/a&gt;</p>
<p>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! <br>Cambria Rhay | http://www.heritageblds.com </p>
<p>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.</p>
<p>This was my first instructables that I watched here,back in the days. Now I found it! </p>
<p>blending of concrete in an everyday shape like a light-bulb is genius. congrats..</p>
I hope you don't mind...I placed a link to your site on my site... http://cehalles.wordpress.com/2014/03/13/my-simple-creations/...I needed good instructions for hollowing out the light bulb and urs are very clear...thanks
<p>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.<br><br>Thanks!<br><br>Xavier Smith | http://www.jbsroof.com </p>
<p>That is very cool and very creative to do something like that. That is very unique and I have never seen something like that before in my life. I do not know if I would ever have one in my house or get it for someone, but it is definitely cool. I am just wondering who owns one of these or even purchased it for someone else.</p><p>Jak Manson | <a href="http://www.bdexteriors.com" rel="nofollow">http://www.bdexteriors.com</a></p>
<p>That is really cool! I remember learning how to make clay vases by wrapping the clay around the bulb, then baking it and breaking the light bulb. It was very cool</p><p>George Puzo | http://www.anviliron.net </p>
<p>This is really cool. I can't wait to try this out. I hope my wife likes this. http://wen-designs.com/index.php/services/</p>
<p>I really like that. It is very unique and would give a little personality to things. </p><p>Jean | http://www.burbachexteriors.com/projects/type/renovation</p>
<p>I really like that. It is very unique and would give a little personality to things. <br>Jean | &lt;a href='http://www.burbachexteriors.com/projects/type/renovation' &gt;Renovation By Burbach&lt;/a&gt;</p>
That looks awesome! I should do something like that around my house, I think that it would be kind of funny, but effective. <br> <br>Jason. <br>http://www.4cornersfencingco.com/

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Bio: Named "Emblematic of the Instructables Universe" by the New York Times, I'm a maker and designer who enjoys looking at things sideways and playing ... More »
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