Removing yellowing from Amigas with peroxide - Page 4

Kristian95 · 12 July 2008, 06:19

in general all chemical processes are sped up by adding heat, even exothermic reactions (heat producing ones), having said that UV might, for this specific reaction, work better, but what we should compare is the energy added to the system (i.e. KJ or calories of UV vs. heat)

EDIT: I am a chemical engineer so I know what I talk about

laser · 12 July 2008, 07:03

I think that heat and light will accelerate the process cause the dentists use a powerful light to accelerate the process while the bleach is in process

also they make hot the product with heat' water before application

rkauer · 12 July 2008, 09:12

Yeah, chemistry basis.

I'm a plastic engineer, myself. But never learnt about removing anti-UV with peroxide.

The anti-UV compound is what makes Amiga cases yellow, not the ABS itself.

Zetr0 · 12 July 2008, 14:23

A bubble tank would really assist this guys,

Grab a small fish tank, attach an air pump with a diffuser on the end of it. around 30-40% peroxide solution and a couple of 30watt UV lamps.... should make a HUGE difference

Paul_s · 12 July 2008, 15:22

Last night a Loreal hair shampoo advert came on.

If we got the secret peroxide formula and marketed it we could have Dizzy naked with an Amiga on the telly..

Lo-peroxide, because your Amiga's worth it...

CRAZG · 12 July 2008, 16:12

I'm glad this has proven to work cause I was sus on the background of the first two images in the first post of this thread.

T_hairy_bootson · 12 July 2008, 16:29

Does the bleaching process change the surface of the plastic in any way? ie. does smooth glossy plastic become rough and matte?

edit: Oh and post some more pics... this is the amiga makeover thread after all

Retro-Nerd · 12 July 2008, 16:51

There are some nice pics on Forum64, i.e this one:

Charlie · 12 July 2008, 20:29

Peeps like Kristian95 will know a lot more about this process than me...

...H2O2 is going to work a treat on yellowed plastics (I'd use it myself if I could be bothered to buy some) BUT all plastic ages & any such chemical treatment WILL age it faster...
...this results in more brittle plastic.
No big deal most likely but go easy on how long you stew your Amiga - you only want surface changes or you could end up with stuff snapping off!
AND make sure you use a some kind of neutraliser (lots & lots & lots of water will do) so that the reaction stops when you're happy with the result.

laser · 12 July 2008, 23:32

Quote:

Originally Posted by Charlie

Peeps like Kristian95 will know a lot more about this process than me...

...H2O2 is going to work a treat on yellowed plastics (I'd use it myself if I could be bothered to buy some) BUT all plastic ages & any such chemical treatment WILL age it faster...
...this results in more brittle plastic.
No big deal most likely but go easy on how long you stew your Amiga - you only want surface changes or you could end up with stuff snapping off!
AND make sure you use a some kind of neutraliser (lots & lots & lots of water will do) so that the reaction stops when you're happy with the result.

I think that sodium bicarbonate+water can be used as neutralizer....it's normally used to neutralize some products that were treated with acid or any other product to oxidize

Kristian95 · 13 July 2008, 03:24

plain water will do as H2O2 is not an acid or base just an oxidizer

rkauer · 13 July 2008, 03:39

OK.

Final picture of the process.

Now all other caps are "swimming" in peroxide.

But just to prove something, here is the result on those 3 caps I already tested (can someone notice the difference?

):

laser · 15 July 2008, 04:50

well I have bleached 2 yellowed keys...and it works !!! I guarantee

the process took aprox 72hs ...but I think more yellowed=more time

after long time we find a real solution for this !!!! yes !!!!!

thanks Kristian95 for bring the info here to EAB!!!

I haven't used light or heat as acceleration of the process....it doesn't need it...only a small flask inside my house away from light or heat........tomorrow I will post some pics

Kristian95 · 15 July 2008, 07:32

Super

I'm happy to help rescue Amigas

No need to thank me, saving Miggy equipment is all the thanks I could ever want

But you could post some hardware Pr0n for Zetro

chiark · 15 July 2008, 11:08

Quote:

Originally Posted by Kristian95

plain water will do as H2O2 is not an acid or base just an oxidizer

It's slightly acidic... at 20%, it's got a pH of 4.9

It's a strong oxidiser, be careful with it.

Zetr0 · 15 July 2008, 14:00

LOL at 70% H202 is considered a FUEL

Photon · 15 July 2008, 23:21

Excellent! How does the printed stuff, like C= logo and caption on keys fare with this solution?

rkauer · 15 July 2008, 23:31

They not fall out, if is that you asking.

Yellowing under the stickers don't go away, too (the stickers impeding this to occur).

chiark · 15 July 2008, 23:33

Cool. Just announced to the wife that I'm off to get some peroxide. She looked at me suspiciously...

Merlin · 15 July 2008, 23:41

We use 35% H2O2 at work, for bleaching dyestuffs out of our trade effluent and to buffer the pH after neutralising formaldehyde with caustic soda....

Science Abuse Rules!!

12 July 2008, 06:19	#61
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 49 Posts: 498	in general all chemical processes are sped up by adding heat, even exothermic reactions (heat producing ones), having said that UV might, for this specific reaction, work better, but what we should compare is the energy added to the system (i.e. KJ or calories of UV vs. heat) EDIT: I am a chemical engineer so I know what I talk about Last edited by Kristian95; 12 July 2008 at 07:27.

13 July 2008, 03:39	#72
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	OK. Final picture of the process. Now all other caps are "swimming" in peroxide. But just to prove something, here is the result on those 3 caps I already tested (can someone notice the difference? ): Attached Thumbnails

15 July 2008, 04:50	#73
laser Banned Join Date: Aug 2006 Location: Argentina Age: 51 Posts: 648	well I have bleached 2 yellowed keys...and it works !!! I guarantee the process took aprox 72hs ...but I think more yellowed=more time after long time we find a real solution for this !!!! yes !!!!! thanks Kristian95 for bring the info here to EAB!!! I haven't used light or heat as acceleration of the process....it doesn't need it...only a small flask inside my house away from light or heat........tomorrow I will post some pics Last edited by laser; 15 July 2008 at 04:57.

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12 July 2008, 07:03	#62
laser Banned Join Date: Aug 2006 Location: Argentina Age: 51 Posts: 648	I think that heat and light will accelerate the process cause the dentists use a powerful light to accelerate the process while the bleach is in process also they make hot the product with heat' water before application

12 July 2008, 09:12	#63
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Yeah, chemistry basis. I'm a plastic engineer, myself. But never learnt about removing anti-UV with peroxide. The anti-UV compound is what makes Amiga cases yellow, not the ABS itself.

12 July 2008, 14:23	#64
Zetr0 Ya' like it Retr0? Join Date: Jul 2005 Location: United Kingdom Age: 49 Posts: 9,768	A bubble tank would really assist this guys, Grab a small fish tank, attach an air pump with a diffuser on the end of it. around 30-40% peroxide solution and a couple of 30watt UV lamps.... should make a HUGE difference

12 July 2008, 15:22	#65
Paul_s Registered User Join Date: Nov 2006 Location: Amigaville Age: 46 Posts: 3,334	Last night a Loreal hair shampoo advert came on. If we got the secret peroxide formula and marketed it we could have Dizzy naked with an Amiga on the telly.. Lo-peroxide, because your Amiga's worth it...

12 July 2008, 16:12	#66
CRAZG 2 heads are more than 1 Join Date: May 2007 Location: Tauranga / New Zealand Posts: 38	I'm glad this has proven to work cause I was sus on the background of the first two images in the first post of this thread.

12 July 2008, 16:29	#67
T_hairy_bootson Workbitch 1.3 Join Date: Oct 2001 Location: Melbourne, Australia Age: 46 Posts: 2,084	Does the bleaching process change the surface of the plastic in any way? ie. does smooth glossy plastic become rough and matte? edit: Oh and post some more pics... this is the amiga makeover thread after all

12 July 2008, 16:51	#68
Retro-Nerd Missile Command Champion Join Date: Aug 2005 Location: Germany Age: 52 Posts: 12,435	There are some nice pics on Forum64, i.e this one:

12 July 2008, 20:29	#69
Charlie . . Mouse . . Join Date: Jun 2005 Location: Nowhere Age: 55 Posts: 1,792	Peeps like Kristian95 will know a lot more about this process than me... ...H2O2 is going to work a treat on yellowed plastics (I'd use it myself if I could be bothered to buy some) BUT all plastic ages & any such chemical treatment WILL age it faster... ...this results in more brittle plastic. No big deal most likely but go easy on how long you stew your Amiga - you only want surface changes or you could end up with stuff snapping off! AND make sure you use a some kind of neutraliser (lots & lots & lots of water will do) so that the reaction stops when you're happy with the result.

13 July 2008, 03:24	#71
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 49 Posts: 498	plain water will do as H2O2 is not an acid or base just an oxidizer

15 July 2008, 07:32	#74
Kristian95 A4000T owner :) Join Date: Jan 2006 Location: California, USA Age: 49 Posts: 498	Super I'm happy to help rescue Amigas No need to thank me, saving Miggy equipment is all the thanks I could ever want But you could post some hardware Pr0n for Zetro

15 July 2008, 14:00	#76
Zetr0 Ya' like it Retr0? Join Date: Jul 2005 Location: United Kingdom Age: 49 Posts: 9,768	LOL at 70% H202 is considered a FUEL

15 July 2008, 23:21	#77
Photon Moderator Join Date: Nov 2004 Location: Eksjö / Sweden Posts: 5,602	Excellent! How does the printed stuff, like C= logo and caption on keys fare with this solution?

15 July 2008, 23:31	#78
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	They not fall out, if is that you asking. Yellowing under the stickers don't go away, too (the stickers impeding this to occur).

15 July 2008, 23:33	#79
chiark Needs a life Join Date: Jan 2008 Location: England Posts: 1,707	Cool. Just announced to the wife that I'm off to get some peroxide. She looked at me suspiciously...

15 July 2008, 23:41	#80
Merlin AmiBay MegaMod Join Date: Mar 2007 Location: Manchester, UK Age: 62 Posts: 1,163	We use 35% H2O2 at work, for bleaching dyestuffs out of our trade effluent and to buffer the pH after neutralising formaldehyde with caustic soda.... Science Abuse Rules!!

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