Whitening a yellowish spacebar on an IBM Model M keyboard: HOW?

[devhdb]

I have a 'rebel' space bar which, after the years has become quite yellowish and doesn't come out white enough as the rest of the keys after some thorough cleaning with this method:

https://geekhack.org/index.php?topic=32 ... #msg623677

I wonder if it's made of a different kind of plastic...

So what do you do to whiten/bleach key caps such as the spacebar? Shall I use bleach or would I risk damaging the plastic by doing that?

[Ratfink]

It's a Greenock model M, isn't it? A lot of those have ABS spacebars, which are prone to yellowing. A treatment with Retr0bright should make it shiny and new again (for a few years, at least).

[devhdb]

Oh, thanks Ratfink, I'll try that!

[Techno Trousers]

Worst case, you could buy a replacement PBT space bar. Unicomp sells them, but they might not quite match the vintage color.