Removing yellowing from Amigas with peroxide

[stevew]

Just wanted to share my experience, I received my old Amiga that was stored in a garage for 20+ years, it was nice and yellow.



For me I cleaned the case with soapy water first, then used bicarbonate soda of clean any remaining scuffs/marks, IPA to remove the marker that had been used to fill in the Amiga logo and chicken lips logo. Once dried painted on 12% (40 volume) HP creme and covered in clingfilm and put under a UV light for 36 hours. I only occasionally gently rubbed the clingfilm, maybe every 12 hours (not too hard as I did not want to split it).



I then bought another Amiga, here is a side by side photo of my 1st Amiga (left) next to my new addition (right) for comparison



I used the same method on the case, no bi carb this time as it was clean, just yellow. This took a lot long under the UV though, I removed cling film after 36 hours and reapplied HP creme with new cling film and left for another 12 hours.

This image shows the cleaned case with its original keyboard on top to show difference (keyboard in it was from a previous clean)

[Washac]

Why are people still doing this to yellowing cases etc, the yellowing does and will
come back in time, also doing this to the plastic causes a breakdown in its structure causing
it to become brittle I recall reading somewhere.

[dJOS]

Originally Posted by Washac

Why are people still doing this to yellowing cases etc, the yellowing does and will
come back, also doing this to the plastic causes a breakdown in its structure causing
it to become brittle I recall reading somewhere.

None of mine have gone yellow again.

[Jope]

Originally Posted by dJOS

None of mine have gone yellow again.

How long has it been from the earliest one you did?

[dJOS]

Originally Posted by Jope

How long has it been from the earliest one you did?

A couple of years and I live in Australia.

[Jope]

Good to hear this kind of report. :-) People have been rather pessimistic. Which method did you use back then?

[turrican9]

I have been doing retro brighting using cream peroxide since about 2014/2015. It all goes yellow again. It will vary how long it takes. If it had severe yellowing it might not get back to being as yellow again.

Also, each plastic can react differently. Even between A500s. Lately I tried peroxide on very yellowed A500 I got in a recent haul. Ended up with uneven bleaching on the grill and some slight blooming around the keyboard area.

Quite some time ago I had given up on retro brighting but wanted to try on this one since it had quite bad yellowing. I will probably stop doing it completely now. There is no point and the risk of making the plastics look even worse is quite high.

[dJOS]

Originally Posted by turrican9

I have been doing retro brighting using cream peroxide since about 2014/2015. It all goes yellow again. It will vary how long it takes. If it had severe yellowing it might not get back to being as yellow again.

Also, each plastic can react differently. Even between A500s. Lately I tried peroxide on very yellowed A500 I got in a recent haul. Ended up with uneven bleaching on the grill and some slight blooming around the keyboard area.

Quite some time ago I had given up on retro brighting but wanted to try on this one since it had quite bad yellowing. I will probably stop doing it completely now. There is no point and the risk of making the plastics look even worse is quite high.

You can usually prevent the blotchy results by running parts through a dishwasher on low temp to remove surface oils etc. I also stopped using the wrap method as it too seems prone to this - I always use the total immersion method now (like 8-bit guy).

[AmigaHope]

Originally Posted by dJOS

You can usually prevent the blotchy results by running parts through a dishwasher on low temp to remove surface oils etc. I also stopped using the wrap method as it too seems prone to this - I always use the total immersion method now (like 8-bit guy).

His new massive UV blast setup seems to work really well, better than sunlight.

[dJOS]

Originally Posted by AmigaHope

His new massive UV blast setup seems to work really well, better than sunlight.

True, I must try that one day - I suspect the heat thrown off those lights helps too.

[turrican9]

Originally Posted by dJOS

You can usually prevent the blotchy results by running parts through a dishwasher on low temp to remove surface oils etc. I also stopped using the wrap method as it too seems prone to this - I always use the total immersion method now (like 8-bit guy).

I have seen 8bit guys method.

The thing is it's almost impossible to find liquid peroxide or even cream peroxide in Norway. They simply do not sell it to regular persons. The cream peroxide I have was ordered from England. It was a hairdresser cream to bleach hair. I believe it's not legal to sell in Norway. Another thing is that even If I had liquid peroxide and a huge box to submerge something like an A500 case we have almost no sun. North of Norway here. The summers are short and the sun not very strong. Unlike you who live in Australia and have plenty of strong sun and probably easy access to liquid Peroxide

And finding other ways to heat up a big box of water and peroxide like that is not easy.

[Hewitson]

Forget retrobrite. UV light (including sunlight) is the new and improved method.

[turrican9]

Originally Posted by Hewitson

Forget retrobrite. UV light (including sunlight) is the new and improved method.

So would this get rid of blooming/streaking on a retro bright gone bad?

[TjLaZer]

Wrapping in plastic can cause discoloration and marble effect, don’t do the lazy method.

[turrican9]

I am debating using the oven for retro brighting keys. Thinking 50 Celcius for 4 hours. I have nothing to vacuum seal the keys in a bag. So I wonder if I just put them in with some regular plastic wraps and cream peroxide if it could potentially poison/contaminate the oven? I use this same oven to steak pizza and stuff

[DarrenHD]

Originally Posted by turrican9

I am debating using the oven for retro brighting keys. Thinking 50 Celcius for 4 hours. I have nothing to vacuum seal the keys in a bag. So I wonder if I just put them in with some regular plastic wraps and cream peroxide if it could potentially poison/contaminate the oven? I use this same oven to steak pizza and stuff

I have an EPROM eraser on order, has a little drawer you can put chips in. Exposes them to UV light. Usually for EPROMS (like the 40-pin ones where you can burn Kickstart onto them) you would put them in for 30 minutes. If I put some keyboard keys in there, would it work? I will try

Darren

[demolition]

Originally Posted by turrican9

I am debating using the oven for retro brighting keys. Thinking 50 Celcius for 4 hours. I have nothing to vacuum seal the keys in a bag. So I wonder if I just put them in with some regular plastic wraps and cream peroxide if it could potentially poison/contaminate the oven? I use this same oven to steak pizza and stuff

If the oven is indeed only 50 deg C, then it should not cause any problems as long as you can avoid spilling. The question is whether it can actually maintain that temperature - some ovens are very inaccurate at such low settings and sometimes could even go to 100 deg., so you might want to check the actual temperature first.

[turrican9]

Originally Posted by demolition

If the oven is indeed only 50 deg C, then it should not cause any problems as long as you can avoid spilling. The question is whether it can actually maintain that temperature - some ovens are very inaccurate at such low settings and sometimes could even go to 100 deg., so you might want to check the actual temperature first.

So my pizza will not taste cream peroxide?

[demolition]

Originally Posted by turrican9

So my pizza will not taste cream peroxide?

The only vapors coming from it are water/stream and oxygen, so not really an issue and I doubt it has any flavor as long as the stuff you're using is pure (does the finished stuff come with perfumes?). Just make sure the stuff doesn't get into contact with any metal parts in the oven as it will cause it to corrode very quickly. That includes any metal baking trays.

Peroxide is actually used as a disinfectant, so your oven might end up cleaner than when you started. It would become a SARS-COV-2 free zone.

[VresiBerba]

Only have liquid peroxide and no bin big enough for the object. Would gelatin powder work to gel it up?