Hello more knowledgable than me people of OF

If you unscrew the caseback of a waterproof SM300 (I have one from watchco) will you ruin the waterproofness? Does it have to be sealed professionally again or can I just screw the caseback back on and expect the watch to be as waterproof as when it was sealed when made?

It it would like to open it to determine the age of the movement but won't do it if it the sealing is compromised.

(a watchmaker told my wife that I ruined the waterproofness of her TechnoMarine watch when I practiced opening casebacks with a new tool without scratching them, didn't want to practice on my Omegas)

Many thx
T

 

If the seal is in good condition, lubricated with Fomblin grease (or silicone grease) and the case back is installed carefully so that the seal does not bunch up or get pinched, you "should" be okay.

Ideally it should be pressure tested in a dry testing machine after being opened to check the water resistance.

Cheers, Al

 

Ok, I will leave it then since I have plans taking it swimming in the weekend.
Thank you very much Al