Plastic housing whitener suggestions

Tally Ho · Apr 19, 2026

I painted mine with a gloss white paint. If you can spray it, it will be even smoother.

Greg

colemj · Apr 19, 2026

There is no renewing it, only covering it (paint, vinyl, etc). You could wet sand the yellow layer off, but it will just yellow again even faster. I hate white plastic things on boats because they always turn an awful yellow color.

Mark

Rick Webb · Apr 19, 2026

There is some sort of hairdresser stuff that whitens plastic. Developer is what sticks in my head but I'm not sure that's it. I used it on something I was working on and was surprised at the results. I think I still have the bottle on the workbench somewhere, unless it got tidied up without my concurrence.

Dalliance · Apr 19, 2026

I lightly sanded mine and spray painted it with Rust Oleum, semi-gloss. The color was called Refrigerator White. That was in about 2008 and it still looks good because it’s covered.

Rick Webb · Apr 20, 2026

It is developer. Basically, it is hydrogen peroxide in a gel. You can pick it up in beauty supply stores. Lots of instructions for the application on YouTube. Smear it on the plastic, put it in a zip lock bag, then set it in the sun. Amazing how well it works.

Project_Mayhem · Apr 20, 2026

Justin_NSA said:
I just picked up some developer #40 at a beauty supply place. I told her what I'm using it for. She says lots of guys come in for it. Hunters use it to whiten bones, techy guys use it on older computers to restore the original color. I've been enlightened!

I can't wait to see the results! Please take before and after pics!

Rick Webb · Apr 20, 2026

Justin_NSA said:
interesting. I may give it a go. Any side effects? Will it get rid of my grey hair?
I'm guessing it is safe for plastic (?)

Not that I know of

Yes, right down to the scalp

Seems to be

Rick Webb · Apr 21, 2026

We want to see the before and after shots.

It's killing me that I cannot remember what I used it on

Cap'n Deke · Apr 22, 2026

This really depends on the kind of plastic. Not too much you can say about what works and doesn't work until you know that. I'm pretty sure hydrogen peroxide only works for ABS. There aren't a lot of other things you can do that actually work well enough to be worth the effort. You can prevent the yellowing with some coatings but they require too much maintenance for my disposition. If it isn't ABS, the only decent options I know of are to sand and polish up to 3000 grit wet sand, which is labor intensive and probably kills fish or something. Or sand lightly and paint as others have suggested.

One more idea that works for some parts but probably not the part you are dealing with. We had a plastic compass ring and cover that were looking a little worse for wear. Took them to a foundry and they just cast them directly in bronze, using the lost-plastic method. Now we have bronze parts that are perfect replacements for the old plastic ones.

JRacer · Apr 22, 2026

SEM Color Coat paint preceded by Bulldog Adhesion Promoter. Pick it up at an automotive paint store.

Hollypine · Apr 23, 2026

Cap'n Deke said:
This really depends on the kind of plastic. Not too much you can say about what works and doesn't work until you know that. I'm pretty sure hydrogen peroxide only works for ABS. There aren't a lot of other things you can do that actually work well enough to be worth the effort. You can prevent the yellowing with some coatings but they require too much maintenance for my disposition. If it isn't ABS, the only decent options I know of are to sand and polish up to 3000 grit wet sand, which is labor intensive and probably kills fish or something. Or sand lightly and paint as others have suggested.

One more idea that works for some parts but probably not the part you are dealing with. We had a plastic compass ring and cover that were looking a little worse for wear. Took them to a foundry and they just cast them directly in bronze, using the lost-plastic method. Now we have bronze parts that are perfect replacements for the old plastic ones.

Great idea! Not inexpensive, but still starts me wondering what could use bronzing around here...or what perverse prank could be pulled with this (bronze toothbrushes in the cups next April 1).

Cap'n Deke · Apr 23, 2026

Justin_NSA said:
The developer has been on a couple days now. It might be a little whiter, but not nearly as white as the unexposed places. I am trying a reapplication before I give up.

Have you been exposing it to UV? The hydrogen peroxide is only half the technique. It has to be exposed to UV to do its magic, so far as I know.