Removing "Yellowing" From Beige Case Plastics

[zaphar]

Re: Removing "Yellowing" From Beige Case Plastics

This isn't retr0brite....but I imagine that is possible regardless, as retr0brite works on the same principle as sodium carbonate cleaners. Some of these were done over a month ago, it hasn't degraded any yet....but yellowing occurring again in a few years, I would say its very possible. I've read that a clearcoat stops it from happening again....but I'm not going through all that.

Hello, it has been many years later. If you would not mind me asking, have these experienced any yellowing since you brightened them?

[Topcat]

Re: Removing "Yellowing" From Beige Case Plastics

Hello, it has been many years later. If you would not mind me asking, have these experienced any yellowing since you brightened them?

The test subject in THIS POST has not yellowed up again, I still have it.

[370forlife]

Just wanted to share a retrobright technique I have been messing around with and having success with. Sunlight is not always a guarantee where I live, and even on sunny days you get about 8 hours of good sun to work with. Forget about it in the winter. I have heard not many success stories with UV LEDs or CFLs as a substitute.

I had noticed that days when we didn't get much sun but I used hot water had much more progress than days where I did not use hot water. So that got me thinking that heat might be able to be used as a substitute for UV light.

I cut a small piece of 1/8" aluminum and attached a 150w oil pan heater to the bottom, printed some feet for it to stand on. Disposable aluminum/baking trays are used, filled with standard 3% hydrogen peroxide from walmart. The oil pan heater is controlled by a terrarium temperature controller that keeps the peroxide between 150F and 165F, which should be well under the glass transition temperature of most plastics. The subjects are put in and the whole thing is covered. Experimenting with time/temp right now, it seems the higher the temp, the better it works. After about 8 hours progress seemed to slow, I left it for another 4 hours (12 total) and there seemed to be no more improvement, still slightly yellowed. I removed the pieces and dried them one by one, and once they were dried you could hold them in your hand and watch them brighten up in 10-15 seconds or so. See if you can spot the keys that were brightened in this picture:

[pdblues2231]

Excellent.... I must give it a try...

thank you.