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Post by Groundhog66 on Jul 15, 2014 16:42:40 GMT -8
I was perusing Randall's breakdown, of the Marine Master HERE. His opinion of the crown seal, is not very positive. It is somewhat of a surprise, that they went cheap on such an important seal. I can't imagine that it would have broken the bank, to go with a multiple o-ring.  |
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cobrajet25
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Post by cobrajet25 on Jul 15, 2014 21:50:48 GMT -8
The size of the gasket looks more than adequate for the size of the hole. Maybe they were thinking that a smaller stem tube, thus a smaller crown gasket, would be less likely to leak than a large one? Seems Seiko's methodology here is "the fewer holes in the case and the smaller they are, the better". They design all their modern dive watches this way, and have never done a multiple-gasket crown. If you put three crown gaskets in a watch, it suggests to me that you are not confident in the first two doing their job!  |
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Post by seikoholic on Jul 16, 2014 11:46:48 GMT -8
That crown seal style does fine for 7002s and SKX's, and the only reason they're only good to 200m is because the crystal isn't screw-down.
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Myles
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Post by Myles on Jul 16, 2014 17:50:28 GMT -8
That crown seal style does fine for 7002s and SKX's, and the only reason they're only good to 200m is because the crystal isn't screw-down. Bry1975 tested a 7S26-0020 to well over 200 m. It passed! These are overbuilt for sure. 8L35-0010 Marine Master can probably withstand more than 300 m. |
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cobrajet25
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Post by cobrajet25 on Jul 16, 2014 21:06:23 GMT -8
That crown seal style does fine for 7002s and SKX's, and the only reason they're only good to 200m is because the crystal isn't screw-down. Bry1975 tested a 7S26-0020 to well over 200 m. It passed! These are overbuilt for sure. 8L35-0010 Marine Master can probably withstand more than 300 m. Absolutely right. I remember that torture test well. It was a wet test, and the watch went to about 460m of pressure, or 671 psi, without leaking. The only reason the test was stopped was because the fellow doing the test was worried about cracking the crystal. 
That was a box-stock SKX diver, rated to 200m. I am sure a MM would do much better. IIRC, all Seiko divers marked "Professional" on the dial are tested to 150% of their rated depth from the factory (ISO only requires a dive watch passing a 125% test). The MM crown gasket is perfectly fine. |
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Deleted
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Post by Deleted on Jul 17, 2014 10:26:16 GMT -8
Bry1975 tested a 7S26-0020 to well over 200 m. It passed! These are overbuilt for sure. 8L35-0010 Marine Master can probably withstand more than 300 m. Absolutely right. I remember that torture test well. It was a wet test, and the watch went to about 460m of pressure, or 671 psi, without leaking. The only reason the test was stopped was because the fellow doing the test was worried about cracking the crystal.
That was a box-stock SKX diver, rated to 200m. I am sure a MM would do much better. IIRC, all Seiko divers marked "Professional" on the dial are tested to 150% of their rated depth from the factory (ISO only requires a dive watch passing a 125% test). The MM crown gasket is perfectly fine. Yes, a double or triple gasket setup is only a psychological marketing tool. Think about it for a minute and you will realize that whether there is one or more gaskets, they will all experience the same amount of wear from having the crown/stem screwed in and out so if one is worn enough to allow water in then in all likelihood the others would also. Additionally they would all age and harden at the same rate; so again one or any number would fail similarly. The weakest part of the sealing system is the owners who don't take care to have them checked and do stupid things like wear them in the shower. |
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Post by seikoholic on Jul 17, 2014 10:37:54 GMT -8
Absolutely right. I remember that torture test well. It was a wet test, and the watch went to about 460m of pressure, or 671 psi, without leaking. The only reason the test was stopped was because the fellow doing the test was worried about cracking the crystal.
That was a box-stock SKX diver, rated to 200m. I am sure a MM would do much better. IIRC, all Seiko divers marked "Professional" on the dial are tested to 150% of their rated depth from the factory (ISO only requires a dive watch passing a 125% test). The MM crown gasket is perfectly fine. Yes, a double or triple gasket setup is only a psychological marketing tool. Think about it for a minute and you will realize that whether there is one or more gaskets, they will all experience the same amount of wear from having the crown/stem screwed in and out so if one is worn enough to allow water in then in all likelihood the others would also. Additionally they would all age and harden at the same rate; so again one or any number would fail similarly. The weakest part of the sealing system is the owners who don't take care to have them checked and do stupid things like wear them in the shower. Yup, and crappy seals will kill any watch. Look at that golden tuna that Aaron posted in the other thread. Roached hands, bad lume. Someone took that into water repeatedly with bad seals. All the screw-down crowns and crystals in the world won't stop water if the seals are junk. |
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Post by Groundhog66 on Jul 17, 2014 10:48:13 GMT -8
I guess there can be the remote possibility, that one of the seals could be defective? Definitely not saying it is necessary, but I doubt it would be detrimental.
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