Removing yellowing from Amigas with peroxide

[orjanh]

I've sold my blacklight for now. I'm on the look out for a UV lamp instead. But the only type people are selling second hand on these parts are those tiny nail-polish UV-lamps thingys...

[Prosonic]

this worked on my kitchen cupboards too

Btw,
Anyone have made the experiment?

[salocinx]

I once used a 2500 Watt UV lamp (originally designed for professional photo exposure purposes). I was leaning over the table where the lamp was mounted preparing the Amiga case and I got a pretty tough sun burn on my neck after few minutes! And my Amiga 500 case was almost white after the procedure, using 30% solution with vanish oxy-action as catalysator.

Since there I prefer natural sun light, 10% solution combined with oxy-action.

[Marchie]

In case this is helpful - I just successfully whitened two keyboards - A1200 and A2000:

Used cream peroxide 12% (from chemist/hair salon), covered in cling-wrap to keep it from drying out, left it in the sun all day (sunny winter day, 19°). Worked fine.

The keys look good (and some were VERY yellow). A2000 frame/case is a little uneven, probably due to the cling wrap clinging more in some places than in others. If I wanted a museum-finish I would probably coat one more time to get it absolutely perfect.

To handle the keys, I pried them all off and pressed them into a dough (flour, water, salt) to keep them face-up, then painted on the peroxide with a small brush. Afterwards I soaked the whole lot in water to dissolved away the dough.

[turrican9]

So over 1 year ago I bought a nice and white Amiga 1200 on ebay. It has started to re-yellow now. The seller had probably used cream peroxide to de-yellow it. Point is that I discovered all the springs under the keys had started to rust badly. Probably because the seller was lazy and just painted all the keys with cream while they were attached to the backplate. Same mistake I did on a Amiga 500 keyboard. Anyway, had to take off all the keys and are now bathing all the springs in Vingear over night. Tomorrow I will neutralize the acid with baking soda and water. The springs already look much nicer after several hours in the bath.

[turrican9]

So I've found that you don't need UV light source or sun at all to remove yellowing. What I've done is put yellowed Amiga 500 keys on newspaper on the floor, covered all the keys with 12% 40 volume cream peroxide then put some plastic wrapping over them. I think they have been there for close to 30 hours now and they are really starting to look nice and white. very close to my non yellowed Amiga 500 keyboard. So no artificial UV light and there is no sun. I live far North in Norway and this time of year the sun is completely gone.

However, I have heating cables in the floor. So heat from them probably helps. Cream peroxide has still not dried out. Also doing some Amiga 500 bottom cases. Hard to see on them yet as I have to remove the plastic to see properly. But I did two side expansion port covers last weekend and they looked much whiter after 24 hours. Could see a huge colour difference between them and the chassis when I put them on.

Now waiting for a couple of new top section cases for Amiga 500 from ebay. These should have some yellowing so will try the same thing.

My experience from last spring out in the sun was that the sun is almost to strong and actually bleached some grey keys and ruined one Amiga 500 upper case.

This method seems far safer and within 30 to 48 hours I should get a really nice result I think.

[dJOS]

That's bizarre, must be the heat from your floor because I've tried Amiga keys overnight and nothing happened. A couple of hours in the Aussie sun works perfectly tho.

[turrican9]

Originally Posted by dJOS

That's bizarre, must be the heat from your floor because I've tried Amiga keys overnight and nothing happened. A couple of hours in the Aussie sun works perfectly tho.

Yep. I think it must be the heat. I've read people that think this process has more to do with the heat itself than the UV radiation.

Well, I have the proof on my floor right now.

[dJOS]

Originally Posted by turrican9

Yep. I think it must be the heat. I've read people that think this process has more to do with the heat itself than the UV radiation.



Well, I have the proof on my floor right now.

Hmm, I might have to try it out on my a600 top case which has a small amount of yellowing. I have a small forced air heater in my garage I could use for the experiment on a low setting.

[turrican9]

Originally Posted by dJOS

Hmm, I might have to try it out on my a600 top case which has a small amount of yellowing. I have a small forced air heater in my garage I could use for the experiment on a low setting.

yeah, there is no doubt it's working. the keys were quite yellowed about 30 hours ago and now they are starting to look very close to one of my non yellowed Amiga 500 keyboards. I also put a tank mouse on the floor today which had some yellowing. So will leave it there for a couple of days.

Tomorrow after work the bottom chassis and keys has been on the floor for about 48 hours and I will unwrap them, wash them and take a look.

[turrican9]

what's interesting is I have read alot of posts of people using UV light bulbs and got almost no difference from the yellowing with cream peroxide after 36 or more hours. However, I see some people make small boxes where they use tinfoil to reflect the light better. I am starting to wonder if they have success because heat will be generated in a box like that. And those who just use a UV light source outside a box will have very diminishing results because the lack of heat?

All who put it out in the sun will get results. But the sun gives alot of heat. Anyway, I will never put anything out in the sun like that anymore. Way to unpredictable.

[dJOS]

I've not had any issues with the Aussie sun, when it's out we get very consistent and strong UV + heat from it. Likely due to the lack of ozone layer above southern Australia.

My fair skin (scottish heritage) burns in less than 30 minutes on a hot summer day.

[turrican9]

Originally Posted by dJOS

I've not had any issues with the Aussie sun, when it's out we get very consistent and strong UV + heat from it. Likely due to the lack of ozone layer above southern Australia.

My fair skin (scottish heritage) burns in less than 30 minutes on a hot summer day.

So you've not seen any bleaching of grey keys or grey tank mouse buttons? Another thing I'm thinking about after reading alot about re-yellowing after cream peroxide treatment is some people think that it will re-yellow faster if you de-yellowed it very fast in the sun. What takes 4 hours in the sun may take 36 hours with the method I'm using right now and some people think that maybe the peroxide will work deeper into the plastic in a slow process VS a faster process. Thereby making it less prone to re-yellowing. Who knows..

Looking at the keys on the floor now I can see through the clear plastic wrapping that the spacebar and all the white keys look about the same/very close to as the non yellowed keyboard. Also I cannot see those yellow stripes around the top edge of keys anymore. The grey ones also looks nice. Grey ones will usually get bleach marks when put in the sun from what I've seen.

But hard to say until tomorrow when I remove the plastic wrapping and give them a good clean.

[dJOS]

The only issue I've had is leaving my keys in the solution I use over night was too long and it bleached the key labels slightly. Wasn't an issue I the end because I painted the whole a500 black.

I use this stuff because it's really cheap and great for removing any residues that build up on 20+ year old cases.

[dJOS]

Here's a tank mouse I did, I can't even recall which is the NOS mouse in this photo.

[turrican9]

Originally Posted by dJOS

The only issue I've had is leaving my keys in the solution I use over night was too long and it bleached the key labels slightly. Wasn't an issue I the end because I painted the whole a500 black.

I use this stuff because it's really cheap and great for removing any residues that build up on 20+ year old cases.

So what's your experience with the plastic re-yellowing? I don't think they sell that stuff in Norway. I had to order 12% 40 volume cream peroxide from UK. One and a half year ago I bought a very white A1200 on Ebay. A few weeks back I discovered all the springs had rusted badly. The seller had probably used cream peroxide without removing the springs. Also, the keys has turned quite yellow now. Maybe I should try to de-yellow it with my slow method.

Also spring of this year I de-yellowed an Amiga 600 which had yellowed badly. especially on the floppy drive side. Keyboard was very yellow aswell. Keyboard still look okay but the right side by the floppy has started to yellow again. Maybe try this one aswell with my newly discovered slow but safe method.

Anyway, one almost perfectly white Amiga 500 chassi that only has yellowing on the left expansion side and two Amiga 500 top chassis on the way from ebay. So have alot of stuff to do. Luckily I ordered 1 litre of cream peroxide earlier this year I think it was. Also have some UV lightbulbs on the way from china but not sure if I need them when as my current method seems to work fine. I can just forget about the sun anyway.. it will be gone until late january next year.

[dJOS]

None of my stuff has re yellowed thankfully. Oh that is annoying when folks don't do things properly, I always remove all the keys and put them in a glass jar or zip lock bag by themselves.

[turrican9]

Originally Posted by dJOS

None of my stuff has re yellowed thankfully. Oh that is annoying when folks don't do things properly, I always remove all the keys and put them in a glass jar or zip lock bag by themselves.

That is excellent news!

yeah, really annoying. Sadly I couldn't save the springs. I did this mistake myself once on a Amiga 500 keyboard but soon realised from the forum here that the springs would rust very fast, I hurried up and removed all the keys and put the springs in baking soda and water and managed to save them. Had I known about it on the ebay A1200 I would have managed to save the springs. but 1 and a half year of rusting was too much for the poor springs. I can probably use them but don't want to use rusted springs

[turrican9]

So today I unwrapped the plastic that covered the Amiga 500 keys with Cream peroxide on them. Happy to report they turned out great. Can barely see any yellowing left on them. They are probably 90% back to new look. Again, this was done with no artificial UV light and no sun. Just had them on top of a newspaper on the floor. Keep in mind I have heating cables in the floor and I suspect heat to actually be a much greater trigger than UV radiation itself for this process. And of course, no bleaching marks on the grey keys since no sun was involved.

As for the bottom chassis I can see that the most yellowed one had turned to about the same colour as the almost none yellowed one. But these are bad examples and will be much easier to see when I get the yellowed A500 top section cases from ebay, which I will then try to de-yellow using the floor/heating cables and no UV light method.