Restoring yellowed pc plastics.

[ponder]

I usually just used a brush & soap in the past followed by a good clean with Clean Green.

I was browsing the www.amibay.com site today and came across something very interesting there. If you want to restore old plastics to their original colour look into Retr0bright.

http://retr0bright.wikispaces.com/

http://en.wikipedia.org/wiki/Retr0bright

Retr0bright is a public domain[1] chemical mixture used to remove yellowing from ABS plastic computer cases that were popular in the 1980s and 1990s, such as Commodore, Apple and Amiga computers.[2]. Yellowing is caused by both bromine and exposure to UV light. Bromine is added to ABS plastic, acting as a fire retardant.
Retr0bright is hydrogen peroxide, a small amount of an ‘active oxygen' laundry booster TAED as a catalyst and a UV lamp. Sunlight can be used instead of UV lamp.[3]
The optimum mixture and conditions for reversing yellowing of plastics:
Hydrogen peroxide solution, the stronger the better. 12% works fine. 6% works also, just slower.
UV light, either as sunlight or a UV lamp;
Approx 1/4 teaspoonful per gallon of "Oxy" laundry booster.
Xanthan Gum or Arrow Root can be added to mixture, creating an easier to apply gel.[4]
When making and applying the mixture, one should take proper safety precautions and wear protective gloves and goggles. Hydrogen peroxide can cause serious chemical burns and blindness if splashed in the eyes.