Interesting pressure testing video..

[thewatchguy93]

http://www.youtube.com/watch?v=chfgUuOz6_Y

I found this really simple but a clever way of testing waterproofing


Dino

[rolexertion]

This would only indicate a small amount of water resistance, up to 1 bar. That's only 10 meters, hardly a conclusive test. A better test, if you don't want to use water, would be testing its resistance to air pressure up to however many bars the watch is rated for.

[buddy13]

Originally Posted by rolexertion

This would only indicate a small amount of water resistance, up to 1 bar. That's only 10 meters, hardly a conclusive test. A better test, if you don't want to use water, would be testing its resistance to air pressure up to however many bars the watch is rated for.

I have to completely disagree...that is the only serious pressure test I submit all my watches too, following mods, service etc..You are right, the pressure difference is only 1 bar but here is the catch...

@Dingo93 - That test is a vacuum test.

To pass that test the watch must be able to hold a pressure difference of 1 bar. The air inside the watch which is at 1 bar, would want to escape to the surroundings (which are at almost 0 bar), but the gaskets must be able to stop this. It has 2 great advantages over other tests...

1) It tests whether the crystal is properly seated in its gasket, especially if no threaded crystal retaining ring is present (only Seiko Pro divers and very few others do that)and it is only held by friction (like Rolex divers)..if it is not well seated, it will pop right out. The crystal is roughly 1 inch squared. It would feel the effect of around 14.7 pounds glued to the crystal while the watch is hanged dial down...

2) As opposed to pressure tests from the outside, which tend to INCREASE water proofness during the test by squeezing the parts tighter together and shutting any possible water ingress parts, this system tends to DECREASE the sealing effectiveness of the gaskets during the tests as it is tending to move apart say the crystal from the case or the caseback from the case, this creates a larger space..

I can completely assure you (from experience) that some gaskets are effective and seal at high pressure (due to the afore mentioned squeezing effect) but then leak at lower pressures...

If the watch passes this test, and no visible damage (such as cracked crystal) is shown on the watch then it is waterproof and you can use it to rated depth (i.e. Sub 300m DSSD 3900m etc...) To test the strength of the case and crystal you would need more pressure, but that is not needed in many situations...

My advice is to use this machine rather than the other variances ...

[rolexertion]

Originally Posted by buddy13

I have to completely disagree...
My advice is to use this machine rather than the other variances ...

I think your 'complete disagreement' is based on a misunderstanding of my point. I of course did not say this test should not be done, I simply said it would not show much. Your point that, after the seals are shown to be good it would be a good idea to test to the depth rating, is correct.

I'm not sure at what internal pressure the HEV on watches like the PO, the DS, the SD work, but they might allow internal pressure to escape under vacuum as well, giving the false impression that the crystal gasket is not sealed properly. Afer all, they are there to prevent the popping off of the crystal, aren't they?

[buddy13]

Originally Posted by rolexertion

I think your 'complete disagreement' is based on a misunderstanding of my point. I of course did not say this test should not be done, I simply said it would not show much. Your point that, after the seals are shown to be good it would be a good idea to test to the depth rating, is correct.

I'm not sure at what internal pressure the HEV on watches like the PO, the DS, the SD work, but they might allow internal pressure to escape under vacuum as well, giving the false impression that the crystal gasket is not sealed properly. Afer all, they are there to prevent the popping off of the crystal, aren't they?

They open at around 3 bar so no problem with vacuum pressure testing ...