# Etanche Back Question



## john87300 (Oct 12, 2011)

Afternoon all

I've just got hold of another old French watch, this time a 17 jewel one, and have been trying to take the back off to see whether it's a Cupillard 256-10 or not. It's an Etanche, waterproof back. Ok, so, with a bit of strain I removed the retaining ring, and exposed a sealed cover. Does this cover just "pop" off, and, if so, is there a seal that may need to be replaced? Obviously this is obvious to those who know, but, sadly, not to me! So I just replaced the ring and started up the laptop to ask those who do know.


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## William_Wilson (May 21, 2007)

I'm not familiar witht that watch, but yes, generally that style of back just pops off after the ring has been removed. There may be a small recess that you can insert the edge of a tool to pry it. The gasket may have turned to gunk over the years, and is causing the cover to stick in place.

Later,

William


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## john87300 (Oct 12, 2011)

William_Wilson said:


> I'm not familiar witht that watch, but yes, generally that style of back just pops off after the ring has been removed. There may be a small recess that you can insert the edge of a tool to pry it. The gasket may have turned to gunk over the years, and is causing the cover to stick in place.
> 
> Later,
> 
> William


Hi William, thanks for the info. The inner back looks a bit like a sixties Time in the way that there's no indent or notch to get my case knife into, My concern was that after 60 years any seal would have, as you say, turned into gunk, and that prying it off would cause bits of junk to fall into the movement, which at present is running like a train..


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## William_Wilson (May 21, 2007)

Yes, contamination could happen. Have you looked at the perimeter of the caseback with a loupe? Sometimes there is an ever so slight widening, that is imperceptible to the naked eye.

Usually a couple of taps with a fingernail loosens them up, but gasket goo or slight corrosion wouldn't be surprising.

Later,

William


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