Removing yellowing from plastics - Part 2

[modem7]

Yesterday and today I tried out the de-yellowing process on a Vic-20. It worked a treat!!. I found a simple food thickener made a great paste, and hydrogen peroxide solutions of only 6% (hair bleach strength) are sufficient. I've documented the experience in my blog.

Thanks for that. I don't really have anything of significance to de-yellow, but your use of relatively easy-to-obtain ingredients inspires me to try it out.

[tezza]

Wow, it really looks nice. Perhaps the strength of the hydrogen peroxide depends on which kind of catalyst you mix it with, or simply the strength of UV?

I must admit, given that the peroxide was a low 6% and it was a cloudy day all day with no clear sunshine (so less UV than normal), I was pleasantly surprised at the result. I'd expected it would need a second day (and another mix) but after 8 hours it was about as de-yellowed as it could be!

It will be interesting to see how the other cases go.

If Merlin, or anyone with some chemistry background and a knowledge of this process, is reading this it would be interesting to know if the sodium percarbonate in the Oxi-magic IS the same as the tetra acetyl ethylene diamine in the Oxy mentioned earlier in this thread, or if it is another compound that catalyizes the same reaction (and is perhaps stronger?) ?

Tez

[Unknown_K]

Hi,

I thought it was probably better to use this old thread rather than make a new one.

Yesterday and today I tried out the de-yellowing process on a Vic-20. It worked a treat!!. I found a simple food thickener made a great paste, and hydrogen peroxide solutions of only 6% (hair bleach strength) are sufficient.

I've documented the experience in my blog.

Cheers

Tez

That was one uggly yellowed vic20.

So when is somebody going to complete this project and come up with a UV resistant non glossy coating that will keep systems you just cleaned from turning yellow again in a year?

[Druid6900]

That was one uggly yellowed vic20.

So when is somebody going to complete this project and come up with a UV resistant non glossy coating that will keep systems you just cleaned from turning yellow again in a year?

Since the process neutralizes the bromide radicals in the fire retardant, theoretically, it shouldn't yellow again.

[patscc]

Unkown_k asked...come up with a UV resistant non glossy coating

They have. It's called Krylon. Check it out.

http://www.shoptheartstore.com/produ...A3D3&showNav=0

Don't know if this is matte or low-gloss version, but they're out there, somewhere.

patscc

[tezza]

I've recovered enough from New Year's eve celebrations to continue my de-yellowing binge today.

My Atari 130XL



This was another complete success like the Vic-20

My cheese-coloured RX-8800



Acceptable, but no where near as even as the Vic-20 and Atari130XL.

Check out the full details and reflections in my latest blog.

Tez

[Unknown_K]

I might try that with my 1040ST (same color plastic as that 130xe) because it is yellowed and now with a non yellowed mono monitor the yellowing REALY is starting to bug me.

[carlsson]

Maybe it has been mentioned before, but don't regular solariums emit UV light of the right wavelengths? If not, perhaps the lamps can be exchanged to ones that do, in case people already own half or full body solariums in their homes.

As for sunlight in the winter, I think the amount of UV light varies over the year and place, not to mention you rarely have a full day of bright sunlight in the winter. At least not over here.

[tezza]

Maybe it has been mentioned before, but don't regular solariums emit UV light of the right wavelengths? If not, perhaps the lamps can be exchanged to ones that do, in case people already own half or full body solariums in their homes.

As for sunlight in the winter, I think the amount of UV light varies over the year and place, not to mention you rarely have a full day of bright sunlight in the winter. At least not over here.

I'm sure solariums would have the right light. They are not common in homes here in NZ...we get more than enough UV! In fact solariums are regarded as a health hazard here.

We sometimes get bright sunny winter days in New Zealand. The blog entry about that was more for when it might be best for me.

I once spent 2 months in the UK during winter. I'm don't think I saw the sun once!

Tez

[Merlin]

Tezza,

The sodium percarbonate will react with TAED to form peracetic acid and sodium carbonate, then will degrade further to produce peroxide molecules; it's essentially a peroxide donor and will make your H2O2 solution stronger. Peracetic acid is also a powerful bleach in it's own right.

If it's reacting, it's the right stuff, simple as.