RetroBright with 3% Hydrogen Peroxide?

[fargo]

I've a badly yellowed Roland CM-500 and I'm thinking of retrobright-ing it!

Using cream hydrogen peroxide may leave marble effect on the plastic, so, I'll try the liquid instead. People on YouTube are using 12% hydrogen peroxide for retrobright, but I only found 3-6% in my local market!

Is 3% or 6% concentration enough for retrobright?

 

[Timo W.]

If it is badly yellowed, probably not. When I was still doing retro-brighting, I once used 5% for some badly yellowed Apple ADB mice. It had very little effect even after a couple of sunny days. I think below 12%, the stuff is just not able to go deep enough into the plastic.

 

[Jove]

My 5 gallons of Hydrogen Peroxide is mixed to about 5% and has worked on everything I throw at at. Apple II, Early 90s PC fronts, Joystick case from the 70s, Joystick from the 80s (I dont even play games, why so many joysticks) etc etc etc.
Head matters as much as sun. A sunny day in the winter won't do anything but a sunny 90 degree F day seems to do the trick just fine.

 

[Timo W.]

Not saying it is not working. But for badly yellowed stuff, the results won't be satisfying.

On the other hand, you don't even need that stuff at all. The sun alone will do. However, you really need more than one perfect hot and sunny day for it to work - not just a few good hours when using hydrogen peroxide.