Yellowed plastics? Retr0bright!

[Kat Manton]

Hi,

I'd read about The “Retr0bright” Project a while ago. I've accumulated yellowed plastic-cased TV sets, computer hardware, the odd bit of test gear and some parts of a few radios have suffered so it was time to give it a try.

The first attempt was with a Sun Type 4 keyboard. I have two of these, both are in a similar state. The keys have suffered the most, the case less so.

Picture = words x 1000 (It's all explained in the link above.)









Finally, for comparison, the keyboard I left untouched in the same shot as the one I treated. They were both in a similar condition initially!



Well, that seems to work!

Now I'm trying it on a Sun Type 3 keyboard case which has turned a deep orange. I was going to either bin it or paint it but after the results above, thought it'd be a good challenge.

I'm still experimenting a bit with the recipe and process so I won't post details yet. I have a couple of bits of test gear, an American 9" portable telly and some bits of radio potentially lined up for treatment (and probably much more.) I'll attempt to get decent before/after photos and post them here.

Cheers, Kat

[murphyv310]

Kat, that is very impressive as is the write up on the link you have posted.
I take Hydrogen peroxide is old fashioned hair bleaching liquid, I have seen OXY "enhancers" in the supermarket, what about the UV bulbs are they readily available?

[Kat Manton]

Hi Trevor,

Watch out for some hydrogen peroxide hair-bleaching products, they may contain other things which attack the plastic (mentioned on the site.) I got 35% solution from an online supplier (so I can dilute it as needed and 500 ml will last longer.) The 'oxy' stuff I'm using is something called "Wizz" which we get from Tesco so was available anyway (I think they're all similar.) The UV (UV-A) bulb is a 20W compact fluorescent 'blacklight' from an online DJ/PA gear supplier (fitted in my ancient desk lamp.)

(For larger items which can't easily be immersed in liquid solution, I'm experimenting with wallpaper paste as thickener as I already had some. I'm not sure how well that's working out yet; I've already had a slight 'mad foaming goo eruption' incident...)

Kat

[russell_w_b]

I had some success with 746 telephone casings without the hydrogen peroxide, and with the case immersed in a solution of Oxywhatever (Aldi stuff, in this instance).

With such a set-up, the UV lamp was useless, so I used a clear plastic box outside. Even on a cloudy day, there was enough natural UV to make it work. Only trouble is it might take a couple of days to achieve a satisfactory result.

[Alistair D]

Hi russell_w_b

What sort of strength was your solution?

Al

[paulsherwin]

Originally Posted by russell_w_b

Oxywhatever

That's probably sodium percarbonate, which becomes hydrogen peroxide once hydrated. Some places sell liquid 'laundry bleach' which is 5-10% hydrogen peroxide. Pharmacists sell 200ml bottles in various concentrations but that may be an expensive way to buy it.

Kat, that's a very impressive experiment. I've tried various bleaches on yellowed plastics but have never followed your procedure. I'll have a go with a few yellow wavechange buttons and see what happens.

[russell_w_b]

Originally Posted by Alistair D

What sort of strength was your solution?

Approx: 15 grammes to 3 litres of warm water. I may not have been exact! I got the idea from Sam Hallas' web-site.

[arjoll]

A great result! I've dealt a little bit with a guy in Palmerston North who has done a number of computers with it (he is one of the guys on the Vintage Computer forum who helped tweak the forumula - screen name is Tezza) but haven't tried it myself.

[frglee21]

Like Russell I've used oxy-cleaner (Vanish in this case) but without the hydrogen peroxide on several ABS telephone cases and handsets.

It works very well on cream or ivory coloured cases but is not so good on darker cases. Everytime, the darker cases have come out of the solution with a "bloom" on them. It does polish off but it's hard work especially on handsets.

Possibly, this is because I haven't added the peroxide - I don't know.

Again like Russell, I put mine outside in a clear or semi-clear lidded box for two or three days turning the box everyday and checking for overall even-ness of colour.

One tip I picked up off the forum was; if your item won't stay submerged in the solution place a glass tumbler on top of it. They are weighty enough and still let light through.

[60 oldjohn]

I am the process of cleaning the famous POLO mint radio. Done front now doing rear. My question to keep process at optimum level should I add more Oxi? And will the Hydrogen Peroxide loose it's stength?


John.

[frglee21]

It's probably better to make up a fresh solution.

I've found that the oxy dissolves better in hand-hot water. If you put too much in - especially if the water is cool - the excess oxy just settles on the bottom in a white sludge.

Regards, Lee.