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Step 6Crack the lightbulb
Let the mortar mix cure for at least 72 hours. A few days more is a good thing.
This is the part where you are breaking up the lightbulb glass into little bits and pieces on purpose.
Glass will be flying in all directions, wear safety glasses and at least one glove (like in the pictures) at all times!
Over a trash can, hold the bulb in one hand that has a glove on it. I've tried to use gloves on both hands at this stage and didn't have the fine control I wanted. You might be able to do it.
Taking a hard metal object, start striking the side of the lightbulb. I'm using my carbride scribe. The glass with start to crack and form spider web fractures. Keep hitting. Eventually small pieces will fall and/or fly off of the bulb. When you have formed a good number of cracks around the bulb, take a toothbrush and scrub it vigorously over the entire bulb. . This will brush into the trashcan any glass grit or loose pieces.
Then take your carbide scribe (or awl or sharp nail) and start to pry up the edges of the glass left on the bulb. Some of it will come off in large chunks, some of it will come off a little piece at a time. Try to aim for the trashcan but know that it won't all go in there, some of it will pop up and go in any direction. If a large piece of glass doesn't want to come up and doesn't have any cracks in it, beat it with the metal object some more to create the spider web. Every so often take the toothbrush and rub down the lightbulb to get rid of any ground in glass or loose bits.
When all the glass has been removed from the lightbulb, take your scribe and carefully go around the neck of the bulb where the metal met the glass. Make sure there are no loose glass shards under the lip of the metal. Shake and tap the bulb to see what floats loose. When you are done, take a shop brush and run it over the entire bulb one more time to get any glass grit or loose pieces out of the holes in the concrete.
It's done! The mortar mix often leaves pits and holes even with all that shaking and tapping you did, but I think it adds a bit of character to the whole thing and makes each one you do unique. Feel the glossy smooth glass finish on the bulb and how it reflects the light. Now it's time to mount it!
This is the part where you are breaking up the lightbulb glass into little bits and pieces on purpose.
Glass will be flying in all directions, wear safety glasses and at least one glove (like in the pictures) at all times!
Over a trash can, hold the bulb in one hand that has a glove on it. I've tried to use gloves on both hands at this stage and didn't have the fine control I wanted. You might be able to do it.
Taking a hard metal object, start striking the side of the lightbulb. I'm using my carbride scribe. The glass with start to crack and form spider web fractures. Keep hitting. Eventually small pieces will fall and/or fly off of the bulb. When you have formed a good number of cracks around the bulb, take a toothbrush and scrub it vigorously over the entire bulb. . This will brush into the trashcan any glass grit or loose pieces.
Then take your carbide scribe (or awl or sharp nail) and start to pry up the edges of the glass left on the bulb. Some of it will come off in large chunks, some of it will come off a little piece at a time. Try to aim for the trashcan but know that it won't all go in there, some of it will pop up and go in any direction. If a large piece of glass doesn't want to come up and doesn't have any cracks in it, beat it with the metal object some more to create the spider web. Every so often take the toothbrush and rub down the lightbulb to get rid of any ground in glass or loose bits.
When all the glass has been removed from the lightbulb, take your scribe and carefully go around the neck of the bulb where the metal met the glass. Make sure there are no loose glass shards under the lip of the metal. Shake and tap the bulb to see what floats loose. When you are done, take a shop brush and run it over the entire bulb one more time to get any glass grit or loose pieces out of the holes in the concrete.
It's done! The mortar mix often leaves pits and holes even with all that shaking and tapping you did, but I think it adds a bit of character to the whole thing and makes each one you do unique. Feel the glossy smooth glass finish on the bulb and how it reflects the light. Now it's time to mount it!
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When cast in glass like it is here, the cement takes the smooth texture of the glass, so it's nice and shiny
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.
http://transienttravels.com/wp-content/uploads/2008/09/p1000768.jpg
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)
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.
You would have to take a door knob, cut it by the wood of the door then cement that in instead of the bolt.