Removing yellowing from Amigas with peroxide

[freesofia]

Here's something from me!
Hydrogen peroxide at 25%, I always stay for 12 hours in the BlueBox at 55 degrees!
It was literally orange, not yellow!

[DanC]

Why is the remove of the yellowing such a big deal?
35+ year old plastic products will have a natural bit of yellowing i think?

[Jolabandola]

Originally Posted by DanC

Why is the remove of the yellowing such a big deal?
35+ year old plastic products will have a natural bit of yellowing i think?

Because in our heads it is still 1992 and our Amigas were still crispy white.

[freesofia]

Originally Posted by Jolabandola

Because in our heads it is still 1992 and our Amigas were still crispy white.

The most accurate answer!

[sviru]

Originally Posted by DanC

Why is the remove of the yellowing such a big deal?
35+ year old plastic products will have a natural bit of yellowing i think?

It looks bad? Like universally bad

[Orionis5]

Anyone made "retro bright" and is still not yellowed after at least 2 or 3 years ?

[demolition]

Originally Posted by Orionis5

Anyone made "retro bright" and is still not yellowed after at least 2 or 3 years ?

I have some devices that were treated in 2013, and while they have reyellowed a bit, they still look reasonably fine. Whiter than before the treatment for sure.

I think it depends on how quickly the treatment is completed. If you use a very concentrated solution and it was completed after 20 mins, then perhaps it is just a very slim outer layer which has been whitened and then it will quickly reyellow from underneath (just my theory). I used 12% peroxide and diluted it down to around 3% so the reaction took quite a bit longer. Some people used undiluted 30% which you can't even get around here.

[Orionis5]

Originally Posted by demolition

I have some devices that were treated in 2013, and while they have reyellowed a bit, they still look reasonably fine. Whiter than before the treatment for sure.

I think it depends on how quickly the treatment is completed. If you use a very concentrated solution and it was completed after 20 mins, then perhaps it is just a very slim outer layer which has been whitened and then it will quickly reyellow from underneath (just my theory). I used 12% peroxide and diluted it down to around 3% so the reaction took quite a bit longer. Some people used undiluted 30% which you can't even get around here.

Great to hear that. I actually admire this work and procedure so it is great to hear it pays off.

[demolition]

Originally Posted by Orionis5

Great to hear that. I actually admire this work and procedure so it is great to hear it pays off.

The best results I have actually had just using the sun - no peroxide or anything. Just clean the part well and put it in the sun for a month or two until it looks good. I had a few experiences with white streaks using peroxide (mainly when experimenting with stronger solutions), but the sun-only method always served me well, although it does require some patience.

Not sure if it is less prone to reyellowing, but I had parts I did that way about 4-5 years ago, and they still look quite good to this day. One of them (a C64C) was very bad and had white blemishes from stickers where it was less yellowed but it all evened out and those blemishes have not reappeared.

[Tchucolate]

My UVBox is called the UVNator


[ Show youtube player ]

Have a watch, its fun, and if you want to see the results from it. Watch this...

[ Show youtube player ]

It certainly works. The concentration of peroxide is a bit of a peice of string, because you HAVE to add water to it, to immerse your items. My rule of thumb is, it should be near 6% ideally, and you should have some kind of tingling on the skin when you put your hands in it. Of course you should wash your hands afterwards, as well as the times removed from it of course.

And as to WHY, well, Im sorry but I come from a time when smoking was rife, and I kind of associate that orangy brown colour with nicotine accumulation on smokers fingers. Ergh... not good...

I want my Amiga's to look pristine, and orange they were not....

[Turran]

My UV box looks similar but with one 150w UV light. This turned out to not be optimal because it gets so hot that it can't even be touched. I thought it would melt the plastic but it does not. It now has a permanent fan on it to cool it down to acceptable levels. It is extremely effective though and I can hear the bubbling going on inside.

https://www.amazon.de/dp/B0B5H5JZFS?...roduct_details

https://grandis.nu/images/Craplinks/uvbox.jpg

Its a standard IKEA storage container with a square hole cut out at the top for the light. The inside is just covered with aluminum tape that reflects well. At first I was going to use mirrors but I read that the glass in mirrors absorbs most of the UV so that is not good to use.
The UV light is just taped with blue tape that is easy to remove afterwards.. mostly just to keep it in place. When not used, the light and fan etc are stored inside the box and stacks nicely with my other IKEA storage boxes.

https://www.biltema.se/en-se/constru...ape-2000017580

I use undiluted 12%. You can buy 3 x 5 liter for less than $80 so I don't care to dilute it. Plus, it can be reused a few times. So far I've only used the first 5 liter container and reused it 3 times without issue. 5 liters is enough to cover everything I put in it so far. Might have to dilute it for larger cases I guess..
I wear protective glasses and plastic gloves when handing it. You can really feel it on your skin after a few seconds so be careful. Wont hurt your skin that bad but do not get it in your eyes.

https://grandis.nu/images/Craplinks/peroxide.jpg
https://www.stadshop.se/p/stadkem/sa...xid-12-5l.html

I did a lot of retrobrighting in ~2012 and some of my images and progress is in this thread. It all went back to yellow after a year or two so I stopped doing it and accepted the yellow, but I want to try it again so... here I am =)

Edit: When disposing of the hydrogen peroxide, I poured some of it it in the shower. It started bubbling like crazy between the tiles and area between them now looks brand new. Heh