How to make yellowed ABS better?

[dantan]

I have an old set of Cherry doubleshots. I notice that the white legends are a bit less than white and am sure they didn't look like that when new.

They are not badly yellowed yet so I don't want to take any risks with this keycap set.

Is there some way I can safely and cheaply make the legends whiter? Can I use bleach?

[davkol]

Retr0bright?

[dantan]

never mind. I can't get the same stuff in my country. and I don't know enough chemistry to know what is the equivalent of the same stuff as bblonde. Wouldn't want to mix several things that I thought are the equivalents, only to blow up my house. I'm not sacrificing so much time and trouble for one set of keycaps that I wish were whiter but aren't that yellowed.

[keykaiser]

Not going to get far with THAT attitude!

[feediko]

I recently used the strongest brand-name hair bleaching kit (blonde), available from any drug store for less than 5 Euro.
Read the instructions, mixed it, smeared it over the Cherry doubleshot caps, wrapped 'em in clingfilm and put them under a 20W UV-Lamp for 5 hours.
Came out pretty good, a little bit too bright even, guess 4 hours would have been enough.

It's really not that much of work, just a little bit messy... just make sure you get something with hydrogen peroxide in it.

This was done with a normal grey/beige set though, if yours is black (?) with white legends, the black plastic might react different and come out dull?

[captsis]

this helped me out with an old NES.

[rm-rf]

all you need is hydrogen peroxide. don't add anything else.
just submerge them and have them sit in the sun for UV exposure. and rotate them every once in a while.
it works great. i've done it a few times now. takes about 3-5 hours for things to get un-yellowed.
i would be more worried about adding other substances, because that could melt your caps.
tbh, retr0bright is a gimmick, you don't need the other stuff that is in it for it to work.
hydrogen peroxide on its own does the job very well.

i just put them in a large clear ziplock bag, and squeeze out the remaining air.

[dantan]

all you need is hydrogen peroxide. don't add anything else.
just submerge them and have them sit in the sun for UV exposure. and rotate them every once in a while.
it works great. i've done it a few times now. takes about 3-5 hours for things to get un-yellowed.
i would be more worried about adding other substances, because that could melt your caps.
tbh, retr0bright is a gimmick, you don't need the other stuff that is in it for it to work.
hydrogen peroxide on its own does the job very well.

i just put them in a large clear ziplock bag, and squeeze out the remaining air.

Hi, thank you for your constructive answer. It is clear and easily put into practice.

I am wondering, apart from ABS keycaps, can hydrogen peroxide de yellow other kinds of plastics? Like polycarbonate for example? I have some old relegendables that might look very nice when de yellowed.