TOPIC:

I want to brighten up some white plasic wheels, so want to buy some Hydrogen Peroxide solution ... I see it's available in 3%, 6%, 9%, 12% and 35% concentrations - so I'm wondering if a concentration higher than the usually recommended 3% would work quicker/better/or make up for the relative lack of sunlight in the UK?

WARNING JONNY The peroxyde is relatively dangerous.
I don't know the reaction with the plastic but it can dry it. Make a test with the 3% before higher concentration...

H.P FREAK's trick is to use aluminium foil on the outside of glass (if I am not mistaken) - and a UV lamp...
I think the 3% solutuion is mostly for "medical" use.
But apart from higher % solutions being quite corrosive, I think it doesn't hurt plastics much :

www.ozonelab.co...es/004.htm

I'm intregued to see exactly what a strong oxidising agent does to plastic, I'll lay money it'll make it brittle, & it wouldn't surprise me if the surface goes powdery too if they're ABS (Maybe not today, maybe not tomorrow, but soon...).
Still, you never know unless you try, & it's better someone else is risking their stuff for me to find out!

Thanks chaps

Chart is interesting ... but what are the wheels made of? I would guess ABS ...

Just been having a read back to see what wheels you plan to "brighten", for a clue as to material type (If they're anything like the ones supplied with my TL, I think they're polyethylene or polypropylene, not ABS or nylon), THEN the mention of UV sunk in - most plastics REALLY don't like UV, normally the addition of colour to the "natural" plastic is to aid UV stabilisation, ie to stop it going powdery & brittle. Most resilient is usually black, least resilient is usually natural/translucent white. Best for showing up damage being done by UV is beige or red

I know you're not a fan of clothes washing detergent, but I've noticed when cleaning bits & bobs in a strong mix of hot water & Tesco value biological washing liquid, white bits often come up quite bright. You could try it as a "safe" option first (Avoid the gag-response by not drinking it)

eddrick wrote:

...

I know you're not a fan of clothes washing detergent, but I've noticed when cleaning bits & bobs in a strong mix of hot water & Tesco value biological washing liquid, white bits often come up quite bright. You could try it as a "safe" option first (Avoid the gag-response by not drinking it)

I would have thought that was down to the optical brighteners in it ("a bluer kind of white", etc) temporarily sticking to the plastic than any bleaching effect TBH



edit - ps it doesn't take a lot of exposure to make me ill, one breath within about 6 feet of it is enough

& yes the chart IS interesting, material of note being aluminium which reacts quickly with oxygen in the air to form an impermeable oxide layer on its surface which prevents further surface oxidation - does aluminium really not react with free oxygen ions, or were they testing with a lump of ally that already had a protective oxide layer?

Another clue to this is when these charts say stuff reacts at low concentrations but not at high concentrations - rather suggests that at high concentrations a protective oxide barrier is formed quickly enough to prevent further oxidation of the "clean" material

Of course, I could be talking rubbish, but it's worth thinking about

Jonny,
Why don't you test to imerge your rims in a solution with 50/50 water and "javel water" (bleach?)?
I use this mixture for my firearms wood parts. Or better, I use Saint Marc wash powder. It is a wash powder with "soude in french". It is efficient and not too agressive.

Yeah I think just try it on something that doesn't matter first, it might be ok.

I wonder what the bluey-whitener stuff in washing detergent is & if there's a way to get it to stick permanently...

If the wheels are polyethylene or polypropylene, they'll be ok soaking in cellulose thinners - haven't tried it but I would've thought it would get rid of anything adhered to the plastic & making it look yellowed.

Spose the fundamental question is "What exactly is the "yellow" on old plastic, is it "on" or "in" the material, is it a physical or chemical change & is it reversible"