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Dumb question about case back gaskets

WhatYourWatchSay
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I picked up an old skin diver. After getting it open I saw the case back gasket was stiff.

I removed the movement and attempted to remove the case back gasket but it was so stiff I was only able to remove a tiny piece. I decided to put everything back together and close it up.

Now the dumb question; was the gasket suppose to be that stiff and impossible to remove, or did the orignal gasket just dry out and become like hard plastic?

I've encounter old dried out gasket before and I can usually remove them, but this one was very resistant to coming out.
 
Canuck
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That is a common situation regarding the deterioration of very old gaskets. Worse than that, though, is the occasional gasket that liquifies, and turns to a gooey mess that seems to spread as the case back is removed. Only solution there is to remove the movement from the case, and apply a solvent that won’t otherwise destroy an acrylic crystal. Be thankful that your problem can be solved by removing the hard gasket in pieces!
 
WhatYourWatchSay
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Canuck Canuck
Worse than that, though, is the occasional gasket that liquifies, and turns to a gooey mess that seems to spread as the case back is removed.

Oh yeah. I'm familiar with those. And the occasional odour that is like blue cheese buried under a chicken coop for a year.

Thanks for the tip, @Canuck. I debated leaving it in a thin layer of acetone but worried about the crystal. I've set it aside and will tackle it again when I have time and when my hands are steady.
Edited:
 
Archer
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What colour was it? Most are black, with the (coveted in some circles) Omega yellow gaskets, and the modern Sinn green gaskets being the exception. These are gaskets that start out as flexible O-rings or flat gaskets, that can harden over time.

But there are also other types of gaskets - some watches used lead rings in the past, and I've come across some thin grey coloured flat plastic gaskets. Those are typically on the case back from what I recall, and can be difficult to remove.

If this is stuck in the case back, I usually remove the hardened ones by physically picking them out, it by bit. This one managed to come out in just a couple of pieces, but some they come out only in small bits, and it's quite a bit of work:



For the black goopy gaskets, I scrape put what I can, and remove the rest with 99% alcohol - it is the best solvent I've found for those, but it doesn't seem to do much on the gaskets that have gone completely hard.

 
WhatYourWatchSay
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Archer Archer
What colour was it?

This one is black.

Archer Archer
If this is stuck in the case back, I usually remove the hardened ones by physically picking them out, it by bit.

I usually have luck with a .60mm screwdriver but this one is particularly difficult--and vexing. I'm going to have to debate using a dental pick but I can just imagine the fun I'll have trying to remove the pick from my thumb.

Edited to add: I think I'm more worried about scratching the case than anything else.
 
WhatYourWatchSay
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philips philips
Would love to see a pic of the old skin diver.

I was going to post a pic but a fellow OF member is a bit pissed off that I got it before him. I don't want to salt the wound.
 
Archer
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WhatYourWatchSay WhatYourWatchSay
I usually have luck with a .60mm screwdriver but this one is particularly difficult--and vexing. I'm going to have to debate using a dental pick but I can just imagine the fun I'll have trying to remove the pick from my thumb.

Edited to add: I think I'm more worried about scratching the case than anything else.

The pick is probably no worse then when I stab myself with the screwdriver...been there, done that. 😀

You could try soaking it, and alcohol shouldn't hurt the crystal - acetone I think would be more of a risk. If you have an ultrasonic tank and there's nothing on the case that would be of concern, that might help loosen it as well. If your ultrasonic has heat, I would use that too.

Does the texture look like it might have bubbles in it? I've found that after the gaskets that turn to black goop age a bit longer, they solidify into a really hard black substance that is almost glass hard, and sometimes has bubbles in it. Almost reminds me of Obsidian and is very difficult to get out.
 
WhatYourWatchSay
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Archer Archer
Does the texture look like it might have bubbles in it? I've found that after the gaskets that turn to black goop age a bit longer, they solidify into a really hard black substance that is almost glass hard, and sometimes has bubbles in it. Almost reminds me of Obsidian and is very difficult to get out.

No bubbles on this one. It's smooth which made me wonder if it was some kind of plastic. It possible could have gone gooey then hard. That is a new one for me.

When I have some free time again I'll give the US machine a go and see what happens.
 
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