I just dipped my Mac SE mouse. It looks amazing now. It took less than 2 hours in 30% peroxide. I can't wait to do the whole machine.
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I also gave my Mac Plus a quick dip. It wasn't too bad, but it could stand to come down a notch.
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All the details and disassembly pics are on my site, ryemac3.net
I've been following this thread with some interest.
Out of curiosity, has anyone tried oxalic acid instead of hydrogen peroxide? It's a great bleach for removing stains from wood and fabric.
If it's some sort of bleach, then I would advise against it. Bleaching is bad, that's basically just stripping color away. The peroxide/oxy solution works because of some serious chemistry. There is a good read here as to why old plastic turns yellow. The fire retardants mixed into plastic changes color over time as it is exposed to UV light. So the oxy/peroxide isn't just "bleaching" it white". It is chemically altering the fire retardants in the plastic back to the color it was.Originally Posted by Chuck(G)
Oxalic acid is a strong reducing agent, which can bleach. It's used a lot to remove rust stains in wood and to bring the color back to stained or discolored wood. So it's not a bleach in the same sense that, say, calcium hypochlorite is.
What's made me wonder about this discussion is exactly the chemistry. Hydrogen peroxide is a strong oxidizing agent, yet the source you cite states that the problem is oxidation. So if your H2O2 isn't bleaching, what's it doing? If the problem was oxidation, it would seem that a reducing agent, not a strong oxidizer, would be the answer.
I guess I'll have to try some oxalic acid to see if it works...
Here's my latest one. It does look a little patchy in spots, but I think the previous owner tried to clean it with something:
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What have you been doing (if anything) to protect the stickers/labels?
They seem to be fairing pretty well.
Nothing, they get treated too. The bar code on the back of the SE faded a little bit and the ones on the back of the mice changed color a little bit. But it's not like they are getting destroyed.
The chemistry is all down to free radicals; the bromine has a single free electron in it's outer shell and it's not totally happy as Br-. What the bromine does is share an electron with an oxygen radical, so that the bromine appears to have eight electrons in the outer shell.
What the TAED does is catalyse the peroxide into hydrogen and oxygen (via peracetic acid, which is a powerful bleach) and it's the hydrogen radical (H+) we are putting onto the bromine, neutralising the single negative charge. The oxygen gets evolved and this is why the solution eventually gets spent.
That's how I understand it, anyway, it's a kind of weird reaction...
While walking through the parking lot at work today I had a thought; would the de-yellowing agent work on the clear (well, supposed to be clear) polycarbonate headlamps on automobiles?
Is that plastic yellowing in a different fashion than the computer cases?
Might be worth a try if someone has the chemicals and yellowed headlamps.
Kent
I have the chemicals, but thankfully a new enough vehicle that the headlight covers are still clear.
I have though, had success previously on old yellowed plastic light covers with a Plastic Polish. (It simply removes the layer of yellowed plastic).
Merlin would be the one to comment on the clear yellowed plastic, but he probably won't know what we're talking about because he never sees enough sun to realize that the clear plastic headlights do go yellow. (My guess is that it's the same cause).
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