Has anyone here got any experience of whitening yellowed plastic on old toys? I've just bought some old Power Rangers stuff, but the plastic is pretty yellow in some places. I've heard of people using Bleach, Hydrogen Peroxide etc, but I'm worried of doing some kind of permanent damage. Is Retr0Bright any good?
You can buy liquid hydrogen peroxide but I've come to prefer the cream type. Basically most hair bleaching creams at 40 vol should work. With cream you can apply it around stickers and colored parts more easily.
Never apply it on metal. The stuff causes rust like crazy.
Get some anti UV hobby spray and coat the parts when you're done. It'll retard the yellowing a bit longer.
I did it mid-last year.
Here is the easiest, cheapest way.
Buy this stuff from a Sally's Beauty store, Salon Care 40 Hydrogen Peroxide Cream. No higher than 40, or it'll scar the plastic.
Take the snes apart, take the shell parts you want to lighten and coat them in a thick layer of the stuff. Put some plastic saran wrap over it (to slow the evaporation) and put it out in the sun. Check back every 5 minutes or so, because it does dry out quick (if it's hot outside it does it even faster), and if it dries out it will ruin the shell. If it starts to look like it is drying out, take it in and apply more.
It took mine about 30 minutes to lighten.
When you're done, rinse it off thoroughly and dry it off.
Here is a video with some info: