!!! IMPORTANT !!! Only do this with double-shot keycapsAlso very important, acetone, like methanol (domestic toxic alcohol) is very volatile and its vapors can cause neuronal diseases (but not only)
use a healing mask or work outside with good ventilation !
(some poor alcoholics ingested methanol, some died, some became blind for life, denatured alcohol is not drinkable alcohol like beer or wine, FYI)
After failing trying to retrObright the keycaps of a 1988 keyboard, although this method worked great with the yellowed shell,
I tried several methods with no results.
I than decided, although I knew the risks, to use acetone.
!!! IMPORTANT !!! Only do this with double-shot keycaps, I never tried this on other types of lettering and would only try on a crap cheap dome keyboard.
Use cotton (the one you find in pharmacies), not cloth, even cotton cloth, IDK why but it works great only with medical cotton.
Put some acetone on a piece of cotton and start cleaning yellowed surface, but clean without pause untill yellow is gone, acetone melts plastic and is very volatile, you must not be afraid to (frotter ?) do like if you wanted to lustrate copper with amoniac.
Result is awesome and takes few seconds, but your keycap will look a bit like if you covered it with glossy clear with a brush, not dramatic but not perfect.
If you want a perfect finition, use polishing paste, I discoverd that polishing paste was much more efficient on recently "acetoned" plastic than on filed (sand-paper) plastic.
This pic is the proof it works, and it took me only 1 minute for a keycap :
This NUMPAD 0 keycap has not even be polished.
Maybe you should try it on spare keycaps first, to train yourself and test your acetone and cotton quality first.Hope this may help
