Two Part case back gasket question

[nlapietr]

Good day.

I am working on a Technos alarm watch.  The case back is like some I have seen on the Poljot alarm watches.  The movement (AS1700/1701) fits into a movement ring and is secured in. That assembly is then inserted into the watch case and a case back which fits onto the back of the movement ring is put on and secured by a separate screw down ring.  the caseback has two tabs to ensure alignment.

My question, and it is probably a dumb one, is where does the gasket go?  It seems to me that to truly be secure one should go between the inside of the caseback on top of the movement ring and another on the opposite side of the case back and the screw ring.

The  existing gasket(s) when I opened the watch had melted and smeared all over so I didn't get a clear understanding of where it/they go.

Any help would be appreciated.

 

v/r

 

N

[tomh207]

The one or two watches I have been inside of with this caseback arrangement have been Russian, however I would expect like them that it would be one gasket and on the caseback. My reasoning is that the caseback makes the seal and the ring is to tighten and make that seal.

Tom