Best way to restore yellowed CPC 6128 keys?

[llopis]

In the past I've used regular oxygen peroxide in the sun with CPC 6128 keys. The results were a bit of a mixed bag: Yes, the color was mostly restored, but some of the larger keys had some noticeable streaking (like some parts got whiter than others). After that, I decided it wasn't worth the trouble to do that again.


Until now.


I have in my possession what might be the yellowest CPC keyboard ever. I have never seen anything this bad. So I'm willing to try something again. Does someone have a better method than oxygen peroxide in the sun for our CPC keys?

[Bryce]

The streaking comes from the peroxide not being evenly spread over the surface. Maybe you just need to try again.

Bryce.

[rpalmer]

The best method i know of to retrobright yellowed plastic is to use a container of water + peroxide and leave covered with "cling"-wrap in the sun for a large period of time. I have seen recent videos where people use "blue" light in a foil covered box to get the same effect of the sun (the heat would be from the device providing the UV light).

rpalmer

[llopis]

The streaking comes from the peroxide not being evenly spread over the surface. Maybe you just need to try again.

That's the thing, I don't think it was because of uneven spread. I had the keys submerged in regular peroxyde solution, so it wasn't a cream. They were in a ziploc bag out in the sun and I moved them every so often. When I took them out, some areas were noticeably brighter, so I thought that maybe some hadn't gotten enough sun, and I put them out another day. All it did was made the bright areas brighter.


It almost felt like the keys were made out of two slightly different plastics that behaved differently to the peroxyde solution.


For the 464 keys I also tried doing peroxyde but on the stove at 50C instead of out on the sun. It was effective in removing the yellowing, but also turned the keys somewhat greyish, so that's not something I'll be doing again.


Anyway, I'll give these keys a try over the weekend and report. They can't get MUCH worse than they already are :-)

[Dagger]

I used to use the hydrogen peroxide with oxi wash which was ok but not for grey keys, used to to go patchy. I now use Bblonde 12% cream which has produced some great results even on the grey keys. Just brush every hour or 2 depending on the temperature and gradually weaken the cream as the day goes on. Some days it can be completed in less than 3 hours depending on the heat and strength of the sun.