672 replies to this topic

[Merlin]

@ all

The best recipe is this:-

1 pint (500ml) 10 to 15% Hydrogen Peroxide solution (do not use stronger than 15%, as low as 6% has been proven to work)
1 tablespoonful (10g) of Corn Flour, Xanthan Gum or Arrowroot (any starchy food thickener will do)
1 teaspoonful (5ml) of Glycerine (it helps the thickener disperse and wet out better)
1/4 teaspoonful (1.5g) "Oxy" laundry booster

Blend the first three items for 30 seconds with a high speed hand blender or liquidiser. Let the mixture rest and 5 minutes later you should have a thick almost clear gel which won't drip from a spoon. This is stable and can be stored. DO NOT add any "Oxy" until you are ready to use it.

Add the 1/4 teaspoonful of "Oxy" and stir it in with a spoon just before you brush it onto the item to be treated. Stick it under a black light or sunlight and check periodically. Once you are satisfied that the colour has been restored, wash all traces of the gel off and allow to dry. Coat with a clear lacquer to seal the oxygen away from the surface and it should stay the restored colour indefinitely.

WoW! 1337 reads! My thread is finally l33t!!

Edited by Merlin, Sat Jan 31, 2009 5:59 PM.

[Stephen]

Merlin, on Sat Jan 31, 2009 6:46 PM, said:

@ all

The best recipe is this:-

1 pint (500ml) 10 to 15% Hydrogen Peroxide solution (do not use stronger than 15%, as low as 6% has been proven to work)
1 tablespoonful (10g) of Corn Flour, Xanthan Gum or Arrowroot (any starchy food thickener will do)
1 teaspoonful (5ml) of Glycerine (it helps the thickener disperse and wet out better)
1/4 teaspoonful (1.5g) "Oxy" laundry booster

Blend the first three items for 30 seconds with a high speed hand blender or liquidiser. Let the mixture rest and 5 minutes later you should have a thick almost clear gel which won't drip from a spoon. This is stable and can be stored. DO NOT add any "Oxy" until you are ready to use it.

Add the 1/4 teaspoonful of "Oxy" and stir it in with a spoon just before you brush it onto the item to be treated. Stick it under a black light or sunlight and check periodically. Once you are satisfied that the colour has been restored, wash all traces of the gel off and allow to dry. Coat with a clear lacquer to seal the oxygen away from the surface and it should stay the restored colour indefinitely.

WoW! 1337 reads! My thread is finally l33t!!

I've been following this for quite some time now. Awesome work to all involved. I have a 130XE, a 520ST, a 1040ST, and an MIO that could use this. When I do get aronud to cleaning them up, I'll take tons of photos.

Stephen Anderson

[Stephen]

Looking at my MIO that needs de-yellowed, I see that it has been written on with a black magic marker. Is there anything that will remove this without damaging the plastic? I don't know what type of marker was used, I assume just the standard black permanent ink marker.

Stephen Anderson

[Guitarman]

I have been able to remove black marker from Atari's with one of those magic eraser cleaners. Don't know if that harms anything but it does a great job removing dark marks. Don't rub to hard though. It will come off with light pressure.

Stephen, on Sat Jan 31, 2009 5:20 PM, said:

Looking at my MIO that needs de-yellowed, I see that it has been written on with a black magic marker. Is there anything that will remove this without damaging the plastic? I don't know what type of marker was used, I assume just the standard black permanent ink marker.

Stephen Anderson

[remowilliams]

Stephen, on Sat Jan 31, 2009 8:20 PM, said:

Is there anything that will remove this without damaging the plastic?

I use this stuff all the time. Very effective at what it does, without harming plastics.

[Bryan]

There'd be a real market for this if it fixes old yellowed headlight assemblies.

[IndusGT]

This is a great thread. Probably the best news for our 8 bits since the Antic Pal upgrade. For those of us that don't have a UV light or ample backyard space, I take it this would do the trick for a source of UV light:

http://www.frozencpu.com/products/2992/lit...ml?tl=g6c75s132

[harpo]

Merlin,
My mistake on the TAED vs. EDTA. I thought it was one of those idiomatic language things like "bonnet/hood", "boot/trunk", "mate/friend"
I did alot of work with polycarbonates developing the very first photochromic prescription eyeglass lenses to compete with the Corning Photogrey/Photosun glass lenses. This would have been back when our A8's were considered new The polycarbonates we made were produced commercially by the reaction of a bis-chloroformate like ethylene glycol bischloroformate and an organic peroxide. Cl-(C=O)-O-CH2-CH2-O-(C=O)-Cl + H-O-O-CH2-(phenyl ring)-CH2-O-O-H => [R-O-(C=O)-O-R]x
Those organic peroxides were really nasty actors But what is interesting is that UV light is what is used to initiate the reaction. The UV light breaks apart the peroxide covalent bond leaving the free radical R-O' . I'm not sure if the hydrogen peroxide also produces free radicals when it is irradiated with UV or if the Br-O bonds are forming them, or both? But, no matter, your protocol works and an empirical result always trumps a theoretical supposition

[mimo]

IndusGT, on Sun Feb 1, 2009 8:14 AM, said:

This is a great thread. Probably the best news for our 8 bits since the Antic Pal upgrade. For those of us that don't have a UV light or ample backyard space, I take it this would do the trick for a source of UV light:

http://www.frozencpu.com/products/2992/lit...ml?tl=g6c75s132

I use one of these
http://www.maplin.co...?ModuleNo=24245

[Merlin]

@ Stephen

Magic Marker will come off with Iso Propyl Alcohol, the stuff you find in car window de-icer. Methylated Spirits should also work.

[Merlin]

Bryan, on Sun Feb 1, 2009 2:27 AM, said:

There'd be a real market for this if it fixes old yellowed headlight assemblies.

Well, if you know someone with an old one, why not give it a shot? The worst that could happen is nothing....

[Merlin]

harpo, on Sun Feb 1, 2009 9:00 AM, said:

Merlin,
My mistake on the TAED vs. EDTA. I thought it was one of those idiomatic language things like "bonnet/hood", "boot/trunk", "mate/friend"
I did alot of work with polycarbonates developing the very first photochromic prescription eyeglass lenses to compete with the Corning Photogrey/Photosun glass lenses. This would have been back when our A8's were considered new The polycarbonates we made were produced commercially by the reaction of a bis-chloroformate like ethylene glycol bischloroformate and an organic peroxide. Cl-(C=O)-O-CH2-CH2-O-(C=O)-Cl + H-O-O-CH2-(phenyl ring)-CH2-O-O-H => [R-O-(C=O)-O-R]x
Those organic peroxides were really nasty actors But what is interesting is that UV light is what is used to initiate the reaction. The UV light breaks apart the peroxide covalent bond leaving the free radical R-O' . I'm not sure if the hydrogen peroxide also produces free radicals when it is irradiated with UV or if the Br-O bonds are forming them, or both? But, no matter, your protocol works and an empirical result always trumps a theoretical supposition

Thanks, I just hope that the rest of the people in here can follow that..... to some, it's a foreign language....

My reasoning is that the TAED degrades to peracetic acid and other ligands. TAED is also a powerful catalyst for peroxides, as it generates peroxides in the laundry when it is mixed with percarbonates and perborates as in the laundry boosters. It's not beyond reason that it breaks apart the peroxide to free radicals. There is a gas evolved as a result of the reaction; I haven't analysed it but the theoretical process would say that oxygen is evolved. The weird thing that people would see if they try the liquid version is once the colour has been restored, the reaction stops; that can only be as a result of all of the bromine free radicals having been converted and the surface is technically inert again. It's cool that we can have this scientific discussion, thanks.

I have never used any chemical for the purpose it was originally intended for, this is how you solve things, by having an open mind.

Science abuse Rules!!

[mimo]

Put the 400 case in for another 6 hours today, very very happy with the results.
Does not show up as well in the photos, but in real life the main body of the case is as new compared with the cart flap (which is now being done)

Made up 300ml of 12% Hydrogen Peroxide (40 vol) from Sally
2 tsp Xanthan gum
_1/4tsp TAED

Total 14 hours under Blacklight in my pantry

Just treated the top half of an 800, results after a good nights kip

[Albert]

mimo, on Sun Feb 1, 2009 5:24 PM, said:

Put the 400 case in for another 6 hours today, very very happy with the results.
Does not show up as well in the photos, but in real life the main body of the case is as new compared with the cart flap (which is now being done)

Looks fantastic!

..Al

[Urchlay]

mimo, on Sun Feb 1, 2009 6:24 PM, said:

Put the 400 case in for another 6 hours today, very very happy with the results.

Don't suppose the 400 keyboard gets yellowed with age? (I haven't seen one in so long, I can't remember how they're supposed to look)

[mimo]

Albert, on Mon Feb 2, 2009 12:59 AM, said:

mimo, on Sun Feb 1, 2009 5:24 PM, said:

Put the 400 case in for another 6 hours today, very very happy with the results.
Does not show up as well in the photos, but in real life the main body of the case is as new compared with the cart flap (which is now being done)

Looks fantastic!

..Al

Thanks, it looks better in the flesh. Like new again and I never thought that I would get to see a new 400 again

Urchlay, on Mon Feb 2, 2009 2:47 AM, said:

mimo, on Sun Feb 1, 2009 6:24 PM, said:

Put the 400 case in for another 6 hours today, very very happy with the results.

Don't suppose the 400 keyboard gets yellowed with age? (I haven't seen one in so long, I can't remember how they're supposed to look)

Nope, no yellowing on the lovely 400 keyboards

[Merlin]

For those who may be interested from a scientific perspective, I've done some more research on this and it would appear that the specific PDBE we are dealing with is one called Tetra Bromo Bisphenol A (abbreviated to TBBP-A).

TBBP-A is extremely photo sensitive to UV light and can under go selective debromination and further photolytic degradation, ending up as chemicals such as 2,4,6 tribromophenol and Bisphenol A. The half life of TBBP-A can be as low as 2 1/2 hours under UV light (which explains quite a bit when you look at our results). There is a possibility that these get extracted from the surface and end up in the liquid, although I'm not 100% sure about this.

I have a few abstracts and technical papers to trawl through over the next couple of days, after which I can be a bit more specific on the actual mechanism.

If you 'Google' UV photolysis of TBBP-A, there's quite a lot out there if you are having trouble sleeping.....

[Tempest]

Wow, now I have to go look at my Atari's. I've forgotten how they're supposed to look as I keep thinking that the yellowing is really just the original color (it's hard to tell on the 400/800). So all you have to mask out is the Atari Fuji and any paper labels? Nothing else on the Atari will react to the solution?

I'll admit that I'm more than a bit nervous to try this, but what the heck. It looks like it can work miracles.

Did someone say that this didn't work well on keycaps? My Atari STE keyboard is horribly yellow and could use help.

Tempest

[Allan]

Tempest, on Tue Feb 3, 2009 6:52 PM, said:

Wow, now I have to go look at my Atari's. I've forgotten how they're supposed to look as I keep thinking that the yellowing is really just the original color (it's hard to tell on the 400/800). So all you have to mask out is the Atari Fuji and any paper labels? Nothing else on the Atari will react to the solution?

I'll admit that I'm more than a bit nervous to try this, but what the heck. It looks like it can work miracles.

Did someone say that this didn't work well on keycaps? My Atari STE keyboard is horribly yellow and could use help.

Tempest

You can see the difference between my 1030 which was in it's box until a few months ago and my 1050 drives.

Allan

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[Merlin]

@ Tempest

If you use the gel mixture that I have listed above, it's goof proof. You can paint the gel around the label so that it stays in place. Keep the mixture away from anything aluminium such as badges, unless you cover them up with something waterproof like insulation tape.

The key caps that reported problems were done with 35% hydrogen peroxide, which was too strong; the labels on the keys are laser etched and may fade a little bit but won't come off. The 15% strength should be perfectly OK with keys. You could even get away with 6% hydrogen peroxide.

We have enough tests done now to say with 99.9% certainty that you will be OK. You will know how yellowed it has become if you lift the cartridge flap and look underneath.

[poobah]

Did a test with some 20 vol from Sally.
I think it is probably a little on the weak side.
Also, definitely go with the xanthan gum. I tried using corn starch as a thickener, but it didnt work so well.
It tended to settle back out onto the item, blocking the UV!
I'll do some before and after shots once i get some xathan gum.

[Tempest]

So the best place to get the 10%-15% hydrogen peroxide is from hair bleach?

Tempest

[Frotz]

So, has anyone tried this on a sacrificial SNES case yet? I know the mechanism of discoloration is different, but I'm just hoping.

[mimo]

Tempest, on Wed Feb 4, 2009 5:17 AM, said:

So the best place to get the 10%-15% hydrogen peroxide is from hair bleach?

Tempest

Yes, hair bleach is perfect and also cheap!
FYI I have half an XE keyboard brewing nicely just now. Results before bed time

[mimo]

Frotz, on Wed Feb 4, 2009 6:50 AM, said:

So, has anyone tried this on a sacrificial SNES case yet? I know the mechanism of discoloration is different, but I'm just hoping.

I think Longhorn Engineer mentioned that he was going to have a go with a SNES case.
I don't think it will be a sacrifice, worse case is that you spend $5 trying and nothing happens.
Let us know if you do one