Glass blew out during water resistance test

[AP1875]

During a wet test of a homage submariner the glass blew out as I released the pressure (3atm using a Bergeon lever style tester). Not seen this before, can someone explain why it happened?

[Marc]

Your case is leaky. When you pressurised the tester with the watch inside, air was forced into the case, euqualising the pressure inside and outside the case. When you released the pressure in the tester the higer pressure in the case popped the crystal off.

If you had released the air slowly with the watch submerged you would have seen a stream of bubbles which would have shown you where the leak was.

[AP1875]

I was trying to release the pressure slowly, obviously not slow enough....

[AP1875]

To fit the glass back in, do I need to remove the rotating bezel, put the plastic ring on the glass and then push the bezel on top of the glass?

Some videos of watches with rotating bezels have the bezel installed and then the glass is pressed in after.

I'm not sure which method applies?

[jdm]

18 minutes ago, AP1875 said:

To fit the glass back in, do I need to remove the rotating bezel, put the plastic ring on the glass and then push the bezel on top of the glass?

It depends on the particular watch. If the bezel does not get in the way of working on the crystal there is no reason to remove it.

[watchweasol]

Also bear in mind that this watch being a "Homage" watch may have never been pressure tested before as they are what they are. When the glass is re fitted treat the watch for what it is NOT the genuine thing and therefore water resistant not waterproof.

[Tudor]

Re refitting:

It depends on the design of the rehaut and the crystal. Some rehauts have an undercut on the OD and the crystal (should) have a corresponding protrusion that "locks" into that undercut.

But, since it blew off, it is quite possible the "lock" is not there.

All that said, I personally would disassemble the crystal retainer and bezel from the crystal, install the crystal with a schmear of G-S, and then press the retainer on (then the rest of the bezel assembly).

If this is a "click" type bezel, it needs to be completely disassembled before being put back on. If it's a bi-directional one, you can "get away" with not taking it apart, but it is best to do it in pieces to be sure each piece seats correctly.

Some crystal retainers have an o-ring groove on their underside too. Make sure the o-ring is there, and that it is lubed with Molykote 111 prior to assembly. This does not stop leaks, but reduces case corrosion.