Instructables

Step 2: Hollow out the light bulb

In the beginning I found the directions at TeamDroid to be a great help on how to do this. Now that I've done it over a dozen times it's routine. With practice this becomes quick and simple. There is another instructable describing how to hollow out a lightbulb here to get another perspective on it. Teamdroid linked to a GE tech spec on your standard bulb here.

A lot of the time you are poking around inside the lightbulb trying to break off the internal glass bits. Do this over a trashcan and often shake the lightbulb out over the trashcan to get rid of the glass shards. Wear safety glasses at all times. More than once some glass flew up towards my face when I was doing this.

First, grip the metal circle with a blob of solder in the middle at the bottom of the lightbulb with your pliers and gently pry it up from the dark purple glass insulator. This is pulling a wire in the middle that you want to break, so just pull it off.

Once that is done, take your carbide scribe and over a trash can, pry into the hole you just made in the purple glass insulator and break up that purple glass. You want to remove all the purple glass insulator from the lightbulb body. I use the scribe to start some cracks and lift off a section of it, then I follow up with the screwdriver to get the rest. Turn the lightbulb upside down and shake out all the glass bits that have fallen inside.

Inside there is a small glass tube that pokes up into the glass insulator. You might or might not have already broken that off by now. If not, just lever the screwdriver against it until it snaps loose. Empty into the trashcan.

Now you have a hole in the bottom of the lightbulb. At this point I take my pliers and gently bend over the metal tabs on the inside of the hole so there is no "lip" on the inside. Later when you have broken up the rest of the inside pieces, there isn't anywhere for the bits to catch and stay in the lightbulb when you shake it out.

There should be a wire visible inside that's soldered to the side of the metal screw piece. Take your wire cutters and cut the wire as close to the side of the bulb as possible.

Now, the inside has a glass cylinder you need to break off and clean up the edges to finish the job. Take your scribe or screwdriver and put it down into the lightbulb until it meets resistance. Tap it gently until something breaks. Then using the screwdriver, lever against the side of the lightbulb to clean out whatever remaining glass bits are left. You want the neck of the lightbulb to be clear from the hole all the way down the body. Turn the bulb over and shake it out one more time to get rid of the last of the internal glass pieces floating loose.

Take a toothbrush and while dry, push it into the lightbulb and start loosening up the dry white powder. Especially in the neck of the bulb. Don't worry if you can't get the stuff the toothbrush can't reach at this point. I found the bulb cleans out easier if you do loosen up the white powder in the neck before it gets wet.

Now take it over to the sink and add a little soap and water. Scrub around with the toothbrush and shake the bulb to get the water everywhere. Pull out the toothbrush and then wash out the soapy water from the bulb. At this point it's all nice and clean inside without any soapy residue. Set it aside to dry out. Now it's time to mix up the concrete.
 
Remove these adsRemove these ads by Signing Up
kculver13 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!
challes16 months ago
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
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 .
 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.
vknutt2 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).
cincymikeb2 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.
higherlife5 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.
"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.
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.
djfunkshun3 years ago
No need for soap and water just use some salt to get the white out. That's what meth smokers do!
amandamany4 years ago
I think that lightbulbs are diferent here in Brazil, because i could'nt open any of them like you did.
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 Ocere4 years ago
Have you done this personally? I've been looking for a way to get the metal assembly off intact.
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?
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".
BFeely5 years ago
weezer13us5 years ago
a spray bottle works too. a couple sprays in the right place the white film is gone
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.