Watch "caulk" for waterproofing

My digital watch battery died, and while the O ring looks intact, I’d like to “belt and suspenders” by applying something to ensure the watch remains waterproof. Case says 100m which I know is static and so the real moving around depth is less, I’d like it to be able to wash dishes, shower, and swim to maybe 2m deep.
Rubber cement? Any silicone caulk (though I won’t need much, hate to get a big tube of it – some googling shows that there is watch specific stuff (though probably at a higher $/quantity cost). I’d like to use my local Hardware Hank if possible – so they may not have that.

Any ideas appreciated

Brian

It’s not the back case seal you need to worry about.
The real problem areas are the buttons.

If you wanted to put a little silicone grease on the o-rings, that would help with water ingress, but I would be wary of using an actual adhesive.

But the buttons are not affected by me removing/replacing the back. (I never operate the buttons underwater)

Brian

The only way I would ‘belt and suspenders’ this is to replace the o-ring anyway.

And that :wink:

Short answer, it’s not going to work.

Buy a 100m rated dive watch they are plenty cheap. Seiko and Citizen both have excellent models. G shock if you like the rugged look. Water resistance is a difficult task for watches.

He already has a 100m rated watch, that he’s replacing the battery on and is worried about maintaining the water resistance.

OP, I’ve replaced batteries on a 100m watch with no extra maintenance besides making sure the o-ring was intact and clean (no large dust particles). They were perfectly fine down to 30m depth, including using the buttons. I’d say if you’re only worried about getting it wet down to 2m, you’re more likely to mess things up with adding silicone rather than just leaving the o-ring alone.

This is my second battery replacement. After the first one the watch was mostly water resistant (after washing dishes I noticed later that there was some fog on the inside)
The batter turned out be old, thus prompting my second and my desire to make it more water resistant.
But since:
I lost one of the screws
Neither the light nor the beep now work (they did after the 1st replacement)
I just ordered a new watch.

Brian