Anybody know ways to get the yellow out? My mother in law sent this video. Anybody try this? Seems like stickers are scrap with this method.
Toy yellow removal
- Thread starter Darth_Prime
- Start date
I've heard of using Hydrogen Peroxide before, but the UV light bit was new to me. I've never tried it myself, though. Always been afraid I'd ruin something.
Right? I’ve got a B Wing and a Jetfire that could use a dip. I’m afraid like you of making them worse. And as I mentioned, ruining the stickers.
I've used the hydrogen peroxide method before. Took some time, mostly cause the week I decided to do it, the weather was entirely overcast, but it worked beautifully.
Edit: yes, I lost the stickers, but it was a garage sale g1 jetfire that was already missing pieces, so I didn't care.
edit2: found the pictures I took during the process.
Edit: yes, I lost the stickers, but it was a garage sale g1 jetfire that was already missing pieces, so I didn't care.
edit2: found the pictures I took during the process.
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I've always worried about any potential chemical reactions damaging the plastic with these sort of fixes. I know I remember reading about people running into problems with the plastic cracking on MP seekers a number of years ago, and the realization that everyone who had the problem had all used the same chemical to strip paint off for customization. Really bugs me now that I can't recall what it was they were using that was problematic. Anyway, no idea if there are any such concerns for hydrogen peroxide, but I've just been leery of even trying it.
Also, with the peroxide method, I thought I'd read in the past that some people who had tried it had it clean up the whites nicely temporarily, but then the yellowing came back much more quickly and worse than it had been before. Another reason I've been hesitant to try it. I take it that hasn't been your experience wonko?
Also, with the peroxide method, I thought I'd read in the past that some people who had tried it had it clean up the whites nicely temporarily, but then the yellowing came back much more quickly and worse than it had been before. Another reason I've been hesitant to try it. I take it that hasn't been your experience wonko?
Keep the resulting cleaned plastic out of the sun as much as you can, and you shouldn't have a problem. My jetfire is still as white as the day I decanted and re-assembled him. The acting element in both cases (yellowing and whitening.) is UV light.
This comes up a lot in the retro-computing world—naturally—and a few years ago someone hit on the idea of just putting the stuff out in the sun with no chemicals at all. It works, though it takes longer than the peroxide method. Here's the needlessly-long and needlessly-meandering video that kicked it all off:
The long and short of it is that it's probably not exposure to direct sunlight that causes the yellowing in the first place, but indirect sunlight filtered through the window glass, combined with heat and possibly fluorescent lighting. He also speculates that it's less likely to cause the plastic to become brittle, but this hasn't been tested thoroughly. The biggest strike against it is that none of the other major YouTubers in the scene—who should be well aware of it by now—have attempted it, and they won't say why. I think there's a fear that you're literally just bleaching the plastic rather than simply reversing the yellowing effect.
The long and short of it is that it's probably not exposure to direct sunlight that causes the yellowing in the first place, but indirect sunlight filtered through the window glass, combined with heat and possibly fluorescent lighting. He also speculates that it's less likely to cause the plastic to become brittle, but this hasn't been tested thoroughly. The biggest strike against it is that none of the other major YouTubers in the scene—who should be well aware of it by now—have attempted it, and they won't say why. I think there's a fear that you're literally just bleaching the plastic rather than simply reversing the yellowing effect.
I would just look up a retrolabels set for him and do the hydroperoxide method.
A bit of a bump because I have to put this somewhere.
Way back in 2010 or so when this first started coming up, I messaged Rudy Deanin, an extremely knowledgable PhD polymer chemist at UMass in search of an explanation for the photodegradation and the mechanism by which H202 and sunlight worked.
I don't know how I got his name, but I am somewhat abashed in retrospect that I approached him with something so trivial, the man was a Plastics Hall Of Famer with some extreme credentials! 36 patents, 13 books, 313 technical papers. But he was very friendly and helpful. I really enjoyed our little correspondence.
Only just today, however, I learned that this had been just about my LAST chance to have such a correspondence...Dr. Deanin passed away in 2011, at the age of 90.
Here is part of what he told me at the time.
QUOTE(Dr. Rudy Deanin) In answer to your December 8 inquiry, the 3 monomer units of ABS all contain somewhat unstable atoms or groups which are activated by UV + atmospheric oxygen (photooxidation). They all contain double or triple bonds, which absorb UV. When one C=C bond absorbs light, it is only in the far UV, so we don't see it. It activates an adjacent group and forms another (conjugated) C=C group. This C=C-C=C (allylic) group is more active, so it forms a third, and so on. As this conjugated (-C=C-) chain grows longer, it absorbs longer and longer wavelengths. When it is about 6 C=C groups in a row, it reaches the wavelength of visible light, and we see the degradation. As it grows till longer, it absorbs mores and more visible light, and the color grows darker and darker. The reason peroxide and sunlight cause bleaching is that they destroy a C=C bond and break the conjugated chain.
Embrittlement is caused by crosslinking. When UV and/or oxygen attack an unstable -C:H bond, they split it into -C. and .H radicals. When 2 adjacent polymer molecules have -C. radicals, they pair and form a -C:C- crosslink.
That's my simple-minded explanation. If you read very far into the literature, they get much more complicated, sometimes even contradictory.
Rudy Deanin
In short, the yellowing is caused by the formation of chained double-bonds. In another message he explained that the H202 did not restore the original form of the polymer chain, but converted one of the double bonds to an epoxide (C-O-C triangle) interrupting the chain and making the visible color go away. This is why oxidation via peroxide can seemingly reverse a process which is also oxidation (photo-oxidation)....it is not really reversing it, but oxidizing it further. It was a really great discussion....the real geniuses of the scientific field always seem so easy to talk to!
Way back in 2010 or so when this first started coming up, I messaged Rudy Deanin, an extremely knowledgable PhD polymer chemist at UMass in search of an explanation for the photodegradation and the mechanism by which H202 and sunlight worked.
I don't know how I got his name, but I am somewhat abashed in retrospect that I approached him with something so trivial, the man was a Plastics Hall Of Famer with some extreme credentials! 36 patents, 13 books, 313 technical papers. But he was very friendly and helpful. I really enjoyed our little correspondence.
Only just today, however, I learned that this had been just about my LAST chance to have such a correspondence...Dr. Deanin passed away in 2011, at the age of 90.
Here is part of what he told me at the time.
QUOTE(Dr. Rudy Deanin) In answer to your December 8 inquiry, the 3 monomer units of ABS all contain somewhat unstable atoms or groups which are activated by UV + atmospheric oxygen (photooxidation). They all contain double or triple bonds, which absorb UV. When one C=C bond absorbs light, it is only in the far UV, so we don't see it. It activates an adjacent group and forms another (conjugated) C=C group. This C=C-C=C (allylic) group is more active, so it forms a third, and so on. As this conjugated (-C=C-) chain grows longer, it absorbs longer and longer wavelengths. When it is about 6 C=C groups in a row, it reaches the wavelength of visible light, and we see the degradation. As it grows till longer, it absorbs mores and more visible light, and the color grows darker and darker. The reason peroxide and sunlight cause bleaching is that they destroy a C=C bond and break the conjugated chain.
Embrittlement is caused by crosslinking. When UV and/or oxygen attack an unstable -C:H bond, they split it into -C. and .H radicals. When 2 adjacent polymer molecules have -C. radicals, they pair and form a -C:C- crosslink.
That's my simple-minded explanation. If you read very far into the literature, they get much more complicated, sometimes even contradictory.
Rudy Deanin
In short, the yellowing is caused by the formation of chained double-bonds. In another message he explained that the H202 did not restore the original form of the polymer chain, but converted one of the double bonds to an epoxide (C-O-C triangle) interrupting the chain and making the visible color go away. This is why oxidation via peroxide can seemingly reverse a process which is also oxidation (photo-oxidation)....it is not really reversing it, but oxidizing it further. It was a really great discussion....the real geniuses of the scientific field always seem so easy to talk to!
This post belongs in the Allspark hall of fame.
Trust me, an 89 year old scientist who wasn't a big TV star was delighted that a layperson sought his opinion on a trivial but interesting question in his field.
Trust me, an 89 year old scientist who wasn't a big TV star was delighted that a layperson sought his opinion on a trivial but interesting question in his field.
It'd be interesting to find out if anyone in the field of polymer chemistry has figured out which ABS formulations are prone to yellowing and which aren't. We've all seen the photo of the Super Nintendo that's gone two-tone because it was made of two different formulations; I myself have a Commodore 64C (the one redesigned to be a uniform beige) whose keys have partially yellowed but whose case has not. The newest thing I've seen that has yellowed is my dad's 2010 Dell PC, from when they had white cases with black faceplates, but I've never seen an Xbox 360 that's not still perfectly white.
My SNES held out on the yellowing for the longest time. But it did finally succumb.
I'd also worry about any damage that might result from yellow removal though. As long as it's cosmetic and the SNES itself operates just fine, I just see it as a badge of honor. That SNES has been through it for ## years and it's still going.
I'd also worry about any damage that might result from yellow removal though. As long as it's cosmetic and the SNES itself operates just fine, I just see it as a badge of honor. That SNES has been through it for ## years and it's still going.