Removing yellowing from Amigas with peroxide
 

A guy from A1k.org has had success removing yellowing from a floppy cover from his A4000.
He used hydrogen peroxide (H2O2) in the following way:
Ingredients:
- 30% H2O2, water added to lower concentration to 20%
- Plastic container with lid.
- Protective gloves and glasses (always use this when working with H2O2!)
- Tongs to retrieve the Amiga part after bleaching
- His yellowed floppy cover:
He left it sitting in the sun on his balcony for 72 hours.
Here is a before and after shot:
before after

Nice find :great

I recently soaked some banana coloured keys in a mixture of bleach and vanish oxy for two days and left in direct sunlight for a further four days... the results were very good, but not pure white / ivory.

I will try the peroxide test and post my findings.

Thanks for the tip.

Hydrogen peroxide works fine with white or grey plastics as it seems, but take care you have rubber gloves or something else. This stuff etches extremly.

http://www.forum64.de/wbb3/index.php...threadID=19241

http://www.forum64.de/wbb3/index.php...927#post242927

@Retro-Nerd:

Gloves are important but safety goggles are a _must_ get peroxide in your eye and chances are you will never be able to see with that eye again! This also holds true for hypochloride based bleaches.

You can also use a radiator next to your plastic container , if you don't want to bleach the pieces outdoors. I assume heat is the important thing for the bleaching process, not the sunlight. At least a friend of mine told me that. :)

I run a public swimming pool and have sodium hypochlorite at my disposal...i was thinking of trying it...i will now.;)

heat speeds up the process sure, but even just room temperature will do.
UV speeds up the process too.. what happens is:

2 H2O2 -> 2 H2O (water) + O2 (oxygen)

and that bleaches the plastic :)

h2o2 also is used to bleach teeth but is applied in a format of gel instead liquid....a laser light is used as accelerator of the process

btw, concentrations up to 10% is used as medical product to disinfect and 20 % is used very often by some elderly women to tint hair..so I don't believe that 20 % will be so dangerous....precautions about use gloves and lens is really exaggerated

:laughing:laughing:laughing:laughing

lot of womens use 20 % h2o2 everyday to tint own hair.....none of them use lens and none of them remains blind

@laser:

Trust me, if you get 20% H2O2 in your eyes chances are you can wave goodbye to vision from that eye! I am a chemical engineer, I know what I talk about... but if you think it's safe be my guest, just consider yourself warned :)
FYI: H2O2 will oxidize the proteins in your eye, this is a non-reversible process!
An example of messing with proteins in a non-reversible way: fry an egg, and try to turn into a liquid egg again, can't be done.

If you aren't fast to get the eye flushed, you may need a cornea transplant.

What about Sodium Percarbonate?

A lot safer to play with & I've got 3kg of it sitting right next to me :)

PZ.

Potassium Chlorate and some Tate & Lyle

Blimey! That's an impressive change!
What would haappen to the letters on a keyboard though? I've got a very yellow A1200 keyboard.
Anyone tried just Vanish Oxyaction?

I suggest trying it on a key from an old PC keyboard, nothing to lose ;)

@kristian95 - good idea!

I can test the procedure in a brown (really dead, not even a zombie) A500 keycap.http://www.amigabr.org/uploads/smil47d44e0f3bc2f.gif

Hmm... Where wifie put that damn thing?:blased

btw,

anyone have made the experiment?

H-h-hey! :blased

@laser

You refer to the keyboard experiment? I don't think anyone has checked to see whether the lettering survives.