Removing yellowing from Amigas with peroxide

Having watched David "The 8-bit Guy" and his Retrobriting experiments on YouTube; I decided to do an experiment of my own, both with peroxide but one with light and one without light. I am now 100% convinced that there is no need to use any form of UV light in order to Retrobrite...

I currently have 2 A1200s and both were in an equally bad state when I got them; each one very yellow and missing various keys. I decided to just focus on fixing one of them up (for now).

My photo shows both Amigas side by side. Obviously the one at the top is the one I worked on (with some missing key caps stolen from the donor machine). Its case was done with "salon creme peroxide" (12% 40vol), cling film and a day of British sunshine. Worked a charm, but in hindsight, the sunlight just served to keep everything warm.

The key caps were done separately overnight. I shoved them into a large freezer bag and covered with loads of creme peroxide before tying it up. The freezer bag was placed into a mop bucket full of hot water (58C) from the hot tap. I insulated the bucket as best I could with towels to keep the heat in (and the light out). I went to bed, not expecting much to happen, but the result speaks for itself.

I can't comment on the best strength of peroxide or the perfect temperature but my conclusion is that you just need peroxide and heat (and that the peroxide lightens much more quickly than the sun can turn things yellow)!

[wizard66]

Thanks I will give this a try
I have a a1200 that needs some work !!

[RiP]

Originally Posted by dJOS

Agreed, the best option is to put your yellow item in a plastic tub, then coat, then put cling wrap / plastic wrap over the tub itself. This keeps bugs away from it and boosts the greenhouse effect.

Thanks, any other tips to avoid blooming?

[dJOS]

Originally Posted by RiP

Thanks, any other tips to avoid blooming?

Yep, don't direct wrap the item and fully submerge it in the liquid - uneven coatings and cling wrap is what Ime causes the uneven or patchy effects.

[Mr.Flibble]

IIRC the blooming is from the peroxide creme drying out?

[dJOS]

Originally Posted by Mr.Flibble

IIRC the blooming is from the peroxide creme drying out?

Yep, which is why I recommend full submersion.

[highwinder]

Just wanted to share my before and after photo of my A1200 keyboard. After reading through this thread decided to try mixing Vanish powder with water and outside sun exposure for 3 days, results were pretty good.

To stop the keys floating I split them over 3 take away tubs with just enough mixture to submerge them. Made sure they were all the right way up and then covered the containers with cling film to keep them submerged. Gave them all a gentle prod every few hours to keep them in the solution.

[nogginthenog]

Wow. I have some Vanish Oxi Action "Fabric Stain Remover" under my sink that's probably 5+ years old.

Impressive. This stuff is cheap and readily available in at least AU & UK.
Main ingredient listed is Sodium Carbonate Peroxyhydrate.

Winter is approaching here in the UK but I have some UV sources.
I like this!

[Mrz]

Originally Posted by coolname

I am now 100% convinced that there is no need to use any form of UV light in order to Retrobrite...

that's right
it works even in the darkness
The UV light is just a myth , which for some ppl accelerate the process, but is not true , or if is true only accelerates just a bit which is not worth spending time adding light or heat

anyways Retrobrite is obsolete , the earth's atmosphere is very corrosive for these bad quality plastics
unless you store the computer in a sealed box in vacuum ,the yellow in these plastics will return again

[mikele]

Mrz: I coudn't agree more. I have success in Retrobrighting Atari ST case without any UV source at all. Just peroxide + few layers of stretch tape and I put it close to the radiator in my room. That's it.

After a few months my once yellowed A500 went to the hideous colour again. It's a good temporary solution or even gimmick if you want to sell your retro computers on evil Bay

[Tavis]

Yeah, I gave up on it. Not worth the effort if it’s just gonna return back and I think it damages the plastic like bleaching it.

[Carston]

Originally Posted by Tavis

Yeah, I gave up on it. Not worth the effort if it’s just gonna return back and I think it damages the plastic like bleaching it.

Good point.

[steveh]

Hmm not sure i'd use this method but it works and he demonstrates it in real time.

[ Show youtube player ]

[Methanoid]

Originally Posted by steveh

Hmm not sure i'd use this method but it works and he demonstrates it in real time.

[ Show youtube player ]

I've seen that... it is basically an abrasive method that removes the top layer. Works well for shiny items not for textured.

Personally I wouldn't do that to any Amiga. But it was a fun video to watch.

[acidbottle]

the yellowing does return but not quite as fierce if the staining had been extremely yellowed.
that said, despite the cost and not original parts, a new case and keys from a1200.net really was worth every penny and will never yellow.

[steveh]

Originally Posted by highwinder

Just wanted to share my before and after photo of my A1200 keyboard. After reading through this thread decided to try mixing Vanish powder with water and outside sun exposure for 3 days, results were pretty good.

To stop the keys floating I split them over 3 take away tubs with just enough mixture to submerge them. Made sure they were all the right way up and then covered the containers with cling film to keep them submerged. Gave them all a gentle prod every few hours to keep them in the solution.

I gave this a go today and was very surprised at the result I did the whole of the number pad keys and the 4 direction keys, 1st washing them then put one scoop of the powder in a takeaway tub with warm water then put all the keys in upside down so that they would sink I then put the tub out side in the sun for 4 hours with great results. Tonight I am doing another batch but leaving them on the sink drain board all night so not getting any sunlight just darkness and the occasional kitchen light, will post both sets of pics tomorrow.

I think these keys may have been done before as there is blooming on the darker keys it must have been my m8 pee as i have acquired all of his Amiga gear after his death. as you can see the keys I did in the kitchen overnight the ones surrounding the arrow keys have hardly changed.

[steveh]

sorry about the pic size dunno what happened.

Edit pic no longer shows so in conclusion don't bother spending more money on hairdressing peroxide cus Vanish Oxy-action works just as well.

Next job is the case.

[scuzz]

The yellowing is caused by the intumescent in the surface which is a fire retardent. To remove the yellow you actually abrade the surface and break its seal. The solution is short term and will go yellow again in time. It also makes the plastic brittle, may not be successful and cause marking of the case. It will also attack other materials. To me it ruins the surface on the plastic. I have 123 Amigas and not one has been tampered with. What is more important to me is that as a collector I would never buy an Amiga that had its surface intumescent removed. I expect old computers to go yellow. Removing its surface coating reduces its durability. I just don't care about the yellowing, cus I don't see it.

Just saying. Sad that these ideas are being promoted as some kind of refurbishment when in fact it is anything but.

http://www.scuzzscink.com/amiga/scuz...ber18_2401.htm

scuzz

[ajk]

Retrobriting does not abrade the surface at all if done correctly (= peroxide is not allowed to dry, complete immersion in mild solution is safest).

Latest developments though show that the bromine fire retardant is not necessarily the reason for the yellowing after all. Peroxide may not even be necessary, good results have been achieved with just sunlight.

[dJOS]

I haven't had the opportunity to test this myself yet due to rubbish weather here in Melbourne atm - however, this video may be of interest to you all.

[ Show youtube player ]