Removing yellowing from Amigas with peroxide

Kristian95 · 07 July 2008, 00:35

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

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

@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 · 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

@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.

Hmm... Where wifie put that damn thing?

laser · 08 July 2008, 18:01

btw,

anyone have made the experiment?

Shoonay · 08 July 2008, 18:04

Quote:

Originally Posted by Kristian95

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

H-h-hey!

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.

07 July 2008, 00:35	#1
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 48 Posts: 498	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

07 July 2008, 00:59	#3
Retro-Nerd Missile Command Champion Join Date: Aug 2005 Location: Germany Age: 51 Posts: 12,388	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 Last edited by Retro-Nerd; 07 July 2008 at 01:09.

07 July 2008, 04:45	#8
laser Banned Join Date: Aug 2006 Location: Argentina Age: 50 Posts: 648	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 Last edited by laser; 07 July 2008 at 07:00.

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07 July 2008, 00:44	#2
Magno Boots Zone Friend Join Date: Feb 2006 Location: Hertfordshire Posts: 688	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.

07 July 2008, 01:24	#4
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 48 Posts: 498	@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.

07 July 2008, 01:31	#5
Retro-Nerd Missile Command Champion Join Date: Aug 2005 Location: Germany Age: 51 Posts: 12,388	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.

07 July 2008, 01:48	#6
DoogUK Doogster Join Date: Dec 2007 Location: Dorset Posts: 1,069	I run a public swimming pool and have sodium hypochlorite at my disposal...i was thinking of trying it...i will now.

07 July 2008, 03:54	#7
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 48 Posts: 498	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

07 July 2008, 09:09	#10
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 48 Posts: 498	@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.

07 July 2008, 13:28	#12
Fingerlickin_B Amiga Nut Join Date: Oct 2006 Location: Belco, Australia Posts: 2,242	What about Sodium Percarbonate? A lot safer to play with & I've got 3kg of it sitting right next to me PZ.

07 July 2008, 14:01	#13
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 13,843	Potassium Chlorate and some Tate & Lyle

07 July 2008, 17:47	#14
alphonsus Registered User Join Date: Apr 2008 Location: UK Age: 49 Posts: 181	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?

07 July 2008, 18:45	#15
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 48 Posts: 498	I suggest trying it on a key from an old PC keyboard, nothing to lose

07 July 2008, 20:29	#16
alphonsus Registered User Join Date: Apr 2008 Location: UK Age: 49 Posts: 181	@kristian95 - good idea!

07 July 2008, 23:57	#17
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 57 Posts: 3,482	I can test the procedure in a brown (really dead, not even a zombie) A500 keycap. Hmm... Where wifie put that damn thing?

08 July 2008, 18:01	#18
laser Banned Join Date: Aug 2006 Location: Argentina Age: 50 Posts: 648	btw, anyone have made the experiment?

08 July 2008, 20:04	#20
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 48 Posts: 498	@laser You refer to the keyboard experiment? I don't think anyone has checked to see whether the lettering survives.

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