Removing UV oxidation off tiles

[Neo]

If you leave Lego in the sunlight for too long it may start to yellow.
The yellowing of grey and white lego tiles is very noticable and because it is due to the oxidation of the plastic surface - normal cleaning agents like oxyclean, bleach, rubbing alcohol, ammonia, or soap will not work. Using abrasives and an ultrasonic cleaner do not work either.

The only solution I found that work is Acetone. It is very powerful solvent and only a drop or two on a rag is needed to clean a 2 by 2 Lego tile. Just rubbing the tile with the rag for less than 5 seconds is enough to restore the tile's color. Use too much Acetone and it will melt/craze/scar the plastic surface making the Lego part unusable. Does anyone know of a milder solvant?

[Brickbuilder0937]

Put the yellowed pieces in a container of hydrogen peroxide (the stronger the better) with a little oxy-clean mixed in, shine a UV lamp on the pieces for a few hours while they are still in the solution and they should come out looking like new.

[dr_spock]

Acetone will also work as a ABS plastic glue if you want to glue Lego together.

[Neo]

I did try 3% hydrogen Peroxide (Drugstore variety) - it didn't look like it was working - but then again I only gave it a minute or two to work. Oxyclean has Hydrogen Peroxide in it so additing it to 3% hydrogen Peroxide solution raises its concentration level. From what I understand, Food Grade +35% Hydrogen Peroxide is considered HAZMAT - and a 70% solution of Hydrogen Peroxide is consider to be rocket fuel. ...

Hydrogen Peroxide sounds more powerful than the Acetone solvent I am currently using.

[Brickbuilder0937]

I didn't know you could get it that strong, I think about 12% is strong enough.

[JaumeBCN]

You guys can use hair decolorator (it's two creams, on with Hydrogen Peroxide and another one that is an 'activator' with ammonia) its what girls use to hide body hair.