Removing yellowing from Amigas with peroxide

[Kristian95]

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

[Magno Boots]

Nice find

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.

[Retro-Nerd]

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

[Kristian95]

@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.

[Retro-Nerd]

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.

[DoogUK]

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

[Kristian95]

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

[laser]

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

[laser]

Originally Posted by Kristian95

@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.

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

[Kristian95]

@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.

[zipper]

Originally Posted by Kristian95

@laser:
FYI: H2O2 will oxidize the proteins in your eye, this is a non-reversible process!

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

[Fingerlickin_B]

What about Sodium Percarbonate?

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

PZ.

[alexh]

Potassium Chlorate and some Tate & Lyle

[alphonsus]

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?

[Kristian95]

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

[alphonsus]

@kristian95 - good idea!

[rkauer]

I can test the procedure in a brown (really dead, not even a zombie) A500 keycap.

Hmm... Where wifie put that damn thing?

[laser]

btw,

anyone have made the experiment?

[Shoonay]

Originally Posted by Kristian95

He left it sitting in the sun on his balcony for 72 hours.

H-h-hey!

[Kristian95]

@laser

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

[Kristian95]

Originally Posted by 5h00n4y

H-h-hey!

UV and heat both speed up the decomposition of H2O2 into H2O and O2 and it is during this process that you get the plastic bleached.

[rkauer]

I'm running the experiment right now. I had to buy a flask of 40% H2O2. Wifie don't use it, 'cause she is brunette.

Here is the "before", standing under my A600 for comparison. Note the A600 is not THAT white as she use to be...

Hope it works.

[Zetr0]

Good luck with this adventure my friend

you know the keyboard has had enough when it turns this colour



I raided that pic from Freds private stash!!!

[rkauer]

Ahahah, ROTFLOLASTC!

[laser]

Originally Posted by rkauer

I'm running the experiment right now. I had to buy a flask of 40% H2O2. Wifie don't use it, 'cause she is brunette.

Here is the "before", standing under my A600 for comparison. Note the A600 is not THAT white as she use to be...

Hope it works.

that A500 keyboard is horrible
that's not yellowed...that's wormy

I think you will need a full factory production of h2o2 to bleach that keyboard




bye

[laser]

Originally Posted by Kristian95

@laser

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

I will make the experiment using a PC yellowed keyboard

I will insert one yellowed key on a small flask....also I will try different proportions h2o2 /water

btw,

if rkauer can bleach his super yellowed A500 keyboard I will be monk

[DoogUK]

All this bleaching...i just have to share a joke with you all.

What do you get if you turn a blonde upside down?

A brunnette with smelly breathe!

[rkauer]

I don't want that kb, anyway. I take a dead A500 for a friend.

But the bloke is a total pig, believe me! Not only the entire A500 is the same colour, but inside I find:

- Dead 'rouches;

- Dead spiders;

- Tons of dust and dry mud, among other disgusting things...

Totally rusted shield, broken down floppy... Surprisingly, the A500 itself still working!

Waiting for another A500 (main board dead), but in perfect mint condition, to assemble (more) one perfect A500.

[Yoto]

Letter Soup recipee:

Some peroxide, keyboard keys, microwave hooven... to speed up the process.
Heat up for 2 minutes at 700W.
This could replace 72 hours of wait.
(Not tested...yet!)

[Kristian95]

I'm not sure I'd heat my plastic components that much. The heat alone could possibly warp the plastic out of shape but then again I'm sure you were just joking

[rkauer]

First day impression: after heat the jar with 3 caps inside (and hydrogen peroxide) into the microwave (1 minute each time, I don't want to warp anything), nothing, niente, nada.

Let the jar "staring a the winter sun" (poetic, huh?), some slightly "clarification"... Or just the caps are more clean...

[rkauer]

I'm shocked!

I take the jar to inside home (not a good thing leaving it outside with dogs and cats).

Opened the flask, wash the caps with normal water and examine: hmm... still yellow... but my eyes catches a difference!

So I put the caps back in the keyboard, and for my surprise, it works!

Can you guys tell me what caps I did the test?

[Kristian95]

Super! and not a dent on the arrow, alt label or "space label" either I foresee many more Amiga discoloration rescues now

[Zetr0]

Originally Posted by rkauer

I'm shocked!

I take the jar to inside home (not a good thing leaving it outside with dogs and cats).

Opened the flask, wash the caps with normal water and examine: hmm... still yellow... but my eyes catches a difference!

So I put the caps back in the keyboard, and for my surprise, it works!

Can you guys tell me what caps I did the test?

!!!!Amazing!!!!

the things one can do with bit of bleach, a microwave and sunlight !!!!!

!!!

I wonder if further aggitation could improve the speed of the process... anyone want to try this solution warmed up in a bubble tank with added UV Light!?

hell you can get that setup cheap enough from any tropical fish store.... or ebay

[Kristian95]

It's ironic how UV is first the bad guy and then the merry helper hehehe

[rkauer]

Now we just need not spread the idea or the peroxide price will raise!

[rkauer]

BTW...

Originally Posted by laser

I will make the experiment using a PC yellowed keyboard

I will insert one yellowed key on a small flask....also I will try different proportions h2o2 /water

btw,

if rkauer can bleach his super yellowed A500 keyboard I will be monk

@Laser:

In what monastery you will enter? The monks will accept you?

[laser]

rkauer,

it seems that works...but the keys are not 100% white like new....still a bit of yellow..anyways good work

let's try this experiment:...try to increase the h202 concentration to something like 30% and wait a cup of days..then post new pics

[rkauer]

I'm using 40% H2O2 right now. Remember this is only one day job! More a couple of days and the keys will become minty again (I hope).

Sorry for the joke, I can't help myself.

But for all matters, this experiment is now done.

Now I will start with real needed hardware. I have one A600 and one 1200D with slightly yellow key caps.

My other A1200 is in a DIY tower, using a mint A2000 keyboard.

[Zetr0]

Ahhhh TC is gonna love this one