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Anyone know or sujest a way to clean out the paint inside a cfl bulb? Answered

I want to clean out the inside glass of a CFL bulb to make a bubblier. Using a small tube to pump air & water threw the glass bulb.

I've tried waiting a day, soaking in soapy water, I tried using a pipe cleaner, (broke the glass), I tried pulling a string with tissue paper, (broke again). Is there a chemical I can use to brake up the paint in the bulb, so I can clean it out with running water later. At the moment I'm trying soaking in peroxide or rubbing alcohol. If that doson't work I'm going for acetone next. After that I'm out of ideas.


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2 years ago

Although I haven't done this with CFL bulbs, I have removed the powdery substance inside incandescent bulbs with water and rice, or water and salt. Could you use water and sand? or some other sort of abrasive? This may not even work as I don't know how resilient the coating is.


2 years ago

That powder can be quite hazardous, so please don't let the suff get airborner or end in your drain.
With the wet method you just put the contamited water in an open container and let if evaporate.
(I do that in my garage)
After that discard the entire container in your houshold rubbish bin.
Please wear gloves and avoid skin contact!

It is easier than what you might think.
A straight tube can be done quickly with a pipe cleaner brush and some soapy water.
The key is to use the detergent directly in the tube, meaning you let a few drops run in and then use the brush with water.
Only good working option I found for these twisted tubes is to use an ultrasonic cleaner.
Fill cleaner with luke warm soapy water, preferably bubble free.
Add a few drops of dishwashing liquid to the tube and fill it completely with water!
Submerge the tube in the cleaner and turn it on.
You might need several rounds but don't have to flush the tube out until you really see the white stuff letting go.
Usually mine are done after 6 to 7 rounds all up with little to no residue left.

There are other methods that still wrk on these tubes but I can recommend any as the health or enviromental hazards would be to great.

Jack A Lopez
Jack A Lopez

2 years ago

Threw the glass bulb? Through the glass bulb?

That powdery white stuff will wipe off, like with a cloth, (where have I heard that one before?) but, as you point out, it is hard to get in there, since it is a narrow, twisty spiral path.

My first though was to pump some kind of slurry through it, so little solid particles would actually bump, and rub, against the inside of the glass. You said you have a pump, right? I mean, since the end goal of this project involves pumping water and air through the glass bulb.

I think the phosphors are some mixture of metal oxides, so another possibility exists an acid capable of dissolving them. I just don't know which acid it would be, or if happens to be a cheap, easily available acid, like vinegar (~5% acetic acid), or lemon juice (~5% citric acid).

There are metal cleaning powders, like brand name "Barkeeper's Friend", which contain oxalic acid. Supposedly that one is good for cleaning rust, because it can dissolve iron oxides.

By the way, if you find something that works, please write back and let me know, because for a while now I have had this fantasy for re-using old CRT (cathode ray tube) picture tubes, and I wanted an acid that could dissolve the phospohors, and the big internal metal screen thing, on the end near where the picture appears.

Jack A Lopez
Jack A Lopez

Reply 2 years ago

As a suggestion for what to use for a slurry with water, my intuition is telling me that some of that cheap, suberabsorbent (water absorbing) polymer powder, like the kind found in disposable diapers, and "artificial snow", as seen in this 'ible,


I think that stuff would work well, because the chunks are small enough to fit inside the glass spiral, and it has a density about the same as the water surrounding it, and it is soft and squishy, so I can almost picture it rubbing against the glass, in much the same way as a tiny, scaled down, window wiping squeegee.

Soaked chia seeds, might also work for the water slurry. I don't know if you have seen soaked chia seeds before, but I think they might also have the right combination of small size, and squishy texture, needed to rub stuff off the inside of glass.


2 years ago

What's True

CFLs contain mercury, a potentially dangerous substance
that escapes from broken CFLs into the immediate surroundings, and
therefore the breakage of a CFL bulb should be handled by carefully
removing the broken bulb and its contents from a home.

What's False

The amount of mercury contained in one CFL bulb poses a
grave danger to a home’s inhabitants, and the mercury dispersed by one
broken CFL bulb needs to be dealt with only by an environmental clean-up