6217-8000 Crystal seal

[Fergus]

Googling reviews/topics shows no physical seal between the acrylic crystal and case.

Is this correct and as per other diver's the acrylic fits directly onto stainless steel.

Hence the move from proof to resist.

I know Seiko state 150M but I just can't see how that would survive not leaking at some stage.

I bought this NOS crystal a while back and was mulling things over.

[leffemonster]

Given it’s a tension ring crystal I wouldn’t expect to see any gasket or seal used. I guess the fact that the crystal is pressed directly into the case and compressed under tension when fitting is what creates the ‘seal’.

I’ve often wondered just how ‘waterproof’ a lot of my older SEIKO watches would have been, especially those that use a ‘W’ crystal that just gets pressed onto the case and then secured with a bezel. But I’m guessing they must have at least some resistance to water ingress, even without a rubber gasket. But I’m sure as hell not going to test them! 

The move from PROOF to RESIST isn't anything to do with materials - from what I understand it’s all to do with the legality of the term ‘waterPROOF’ which I believe was challenged by the USA. I always find it odd that a saturation diver with a rating of 1000m still uses the term ‘water resistant’. The only company I’ve seen that still uses the term ‘waterproof’ is Rotary. 

[Fergus]

I worked in the sub sea industry, hands on manufacture, assembly, offshore and then design for 40 years and we would not consider anything but rubber (all types) for sealing sub sea housings both manned and unmanned. We certainly would not have considered plastic/acrylic.

[HiBeat]

When Duncan aka TheWatchBloke restored my first 62MAS, he ran a water resistance test at the end and it passed at 150 meters.

So the design itself works.  
After years of service probably not.

That said I totally agree I want rubber/elastomer seals in anything I depend on underwater.  But many a watch gets by with tension ring technology.

[acidstain]

Plenty of old school diver watch use the tension ring technology. DT (diver tite) is a thicker dome version of the ET (ever tite) and looks close to a 62mas crystal.

[HiBeat]

Jun 24, 2020 20:01:18 GMT -8 acidstain said:

Plenty of old school diver watch use the tension ring technology. DT (diver tite) is a thicker dome version of the ET (ever tite) and looks close to a 62mas crystal.

I have a lot of diver Tite crystals if you ever need one