H2O2 Whitening of yellowed plastic (Pics! ?)

DiskDoctr wrote:
I read about using hydrogen peroxide to whiten yellowed plastic and thought we'd give it a try on our new to us TT.

We experimented on the stove fan vent. It is inexpensive and we had planned to replace it and the outside door trim. They are the most yellowed and make the camper look a bit dated. We replaced them on our previous camper and were well pleased with the improvement.

Both parts started nearly identical in color.



We used the 40% paste/gel from Sally's Beauty Supply, applied it with an old toothbrush (wear neoprene gloves!) covered it with Saran Wrap, and left it sit in the sun for 2 days. Rinsed it off and tried again, being more careful to avoid shadows for an even effect.

I've read that UV light is much more effective on the H2O2 than sunlight (here in the shadowy countryside). Having proven to ourselves that this treatment does work, we are going to invest in one to speed things up.

Our plans are to do the door window trim, then a Fantastic Fan I pulled from one of our older campers (new but then didn't use it and it yellowed terribly), then some (interior) ceiling vent trim, then the big one: The tub and shower surround.

Anyone who has tried this, please post up your tips and pics!

We'll take more as we progress.

Edit: Maybe someone else can get better pics? The vent is almost new looking, but the color balance on my cell doesn't show it well :(

Another pic:

We do notice a little irregularity in the very smooth surface. Maybe from the Saran Wrap, maybe it was there? In any case, we are going to be more careful to seal the part but not have the plastic laying against the surface.

It looks like it will just polish off?

MEH..

Do it right the FIRST TIME and give it a shot of Krylon for plastics..

Once you have coated with Krylon for plastics you can then use ANY paint color of your choice on top of the Krylon.. The Krylon plastic paint acts like a primer and other paints will stick real well to it..

That is what I did with my replacement plastic door window trim, INSIDE AND OUT.

ONE AND DONE.

Otherwise you will be doing this over and over and each time the plastic will get more and more brittle.

Coating the plastic with paint does several things..

It stops the yellowing and it stops the UV from getting to the plastic in the first place which breaks down the plastic and makes it brittle.