English Amiga Board

English Amiga Board (http://eab.abime.net/index.php)
-   support.Hardware (http://eab.abime.net/forumdisplay.php?f=20)
-   -   Removing yellowing from Amigas with peroxide (http://eab.abime.net/showthread.php?t=37808)

Kristian95 07 July 2008 00:35

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

Magno Boots 07 July 2008 00:44

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.

Retro-Nerd 07 July 2008 00:59

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 07 July 2008 01:24

@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 07 July 2008 01:31

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 07 July 2008 01:48

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

Kristian95 07 July 2008 03:54

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 07 July 2008 04:45

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 07 July 2008 07:07

Quote:

Originally Posted by Kristian95 (Post 431252)
@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.


: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

Kristian95 07 July 2008 09:09

@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 07 July 2008 09:48

Quote:

Originally Posted by Kristian95 (Post 431287)
@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 07 July 2008 13:28

What about Sodium Percarbonate?

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

PZ.

alexh 07 July 2008 14:01

Potassium Chlorate and some Tate & Lyle

alphonsus 07 July 2008 17:47

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 07 July 2008 18:45

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

alphonsus 07 July 2008 20:29

@kristian95 - good idea!

rkauer 07 July 2008 23:57

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

laser 08 July 2008 18:01

btw,

anyone have made the experiment?

Shoonay 08 July 2008 18:04

Quote:

Originally Posted by Kristian95 (Post 431246)
He left it sitting in the sun on his balcony for 72 hours.

H-h-hey! :blased

Kristian95 08 July 2008 20:04

@laser

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


All times are GMT +2. The time now is 22:48.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.

Page generated in 0.07534 seconds with 11 queries