How to make a hole in a light bulb without shattering it

In order to use a light bulb to illuminate the inside of a vacuum chamber, I needed to release the gas contained within the bulb else it would likely have exploded the bulb when the external pressure was reduced. However, I wanted to keep the glass intact in order to protect the fragile filament from my clumsy hands and to provide that soft white glow.

I first tried scoring and breaking only a small piece of the bulb, but that always resulted in an uncontrolled cracking/shattering of the entire bulb. The best suggestion I found on the internet involved using a CO2 laser to make the hole. That would probably work, but I’ll save building a CO2 laser from scratch for another day. Other suggestions typically involved drilling under running water at very low speeds with a very sharp drill bit. Since both patience and drills were in short supply, I tried another method.

I found that by using a metal file at a tangent to the glass, one can very slowly thin the glass in a relatively small area. In my experience, eventually the thinned glass breaks away leaving a small hole. The hole isn’t round and doesn’t form in an absolutely controllable way. Perhaps it may be possible to “punch” a smaller hole after thinning the glass but before it breaks.

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This entry was posted on Sunday, July 7th, 2013 at 1:09 pm and is filed under DIY, Register, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

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