[marks]

are these good enough to seal a 6309 diver for swimming... ???

 

[robbie409]

Why w/should you use an after market gasket?

The original ones are still for sale.

 

[marks]

ok, where can I buy original gaskets for my 6309-7040 diver???

 

[Isthmus]

Try Jules Borel & Co.

 

[robbie409]

0C3060B0A is the partnumber.

I have loads of them, they are also OK for a lot more models.

 

[sharkfinDave]

Just curious. So the aftermarket gaskets are absolute rubbish?
I've never bought any yet. Is there a significant price gap between the two, for someone to not get original?


thanks, Dave.

 

[Isthmus]

Just curious. So the aftermarket gaskets are absolute rubbish?

I don't think anyone has said that. All thats been said is that there are plenty of original ones around, so there is no need to buy aftermarket versions of this particular part. As for the quality of aftermarket gaskets, That would depend on each specific gasket, how well it is made, the material it is made of, and how closely it resembles the original.

 

[The Tiger UK]

Just curious. So the aftermarket gaskets are absolute rubbish?
I've never bought any yet. Is there a significant price gap between the two, for someone to not get original?


thanks, Dave.

I may be wrong but from what i have seen original 6309 case back gaskets seem to sell any were from $7 or $8 each were as the after market ones are about .50c each, with the originals you know they are to Seiko specifications i don't know about the after market ones but i was sent one by a friend and it seemed to fit well, so you pays your money and makes your choice

 

[swedefreak]

...so you pays your money and makes your choice


It's more like "your take your chances."

There's no sense in risking catastrophe for the sake of a few dollars. One must remember today's cost of rehabbing a damaged vintage movement or, for that matter, any movement.

Case in point...

I'm currently putting a rare orange 7548-700H back together that had a LOT of water in it. I'm not quite sure why but a set of genuine new Seiko gaskets failed somewhere. Ironically, the movement is fine but the dial and hands are trashed. Try to find those parts, fellas.

I had to buy an entire watch for over $200.00 and it took nearly six months to finally turn-up for sale. Thanks to Rich, by the way. You've saved my butt on this one.

 

[The Tiger UK]

You mean this could happen to your dial Jonathan ?? try finding one of these dials !!! ???

 

[tcps760]

Aftermarket gaskets are fine, as long as they are made to specs. They're "just gaskets," not complex pieces of engineering. I haven't heard of Seiko using special material to make their gaskets - its all about the proper shape/dimension/size. (Wouldn't using NOS 6309 gaskets from the '80s be questionable?...Rubber does deteriate over time doesn't it? Maybe an engineer or chemist can jump in a give their insight.)

I have pressure tested watches with aftermarket gaskets all around, and they consistently pass to 150m with flying colors. However, with that being said...if you buy gaskets off the bay or elsewhere on some random vague internet site, and the caseback gasket is skinny as heck, not uniform in shape, or overall ratty...then commen sense dictates that you don't use it. Some aftermarket gaskets just don't quite fit properly, which causes them to pinch or not seat, which then causes a weakpoint in the integrity of the watch. A lot of reputable watch dealers will pressure test a watch for the owner's peace of mind, however will not provide a guarantee of "water-resistance" due to the possibility of the owner cross-threading the crown when re-sealing it after setting the time, or just plain not tightening it down enough before jumping in the water. My .02

 

[sharkfinDave]

You mean this could happen to your dial Jonathan ?? try finding one of these dials !!! ???


[/quote]


OMG, John this just made me cringe in pain.
On the bright side, you could redial this into some sort of cool mod.
Good luck with sourcing a dial, hope one lands your way, as I'd love to see yours complete, back to its original. ;)


Cheers, Dave.

 

[Chris Galbraith]

Aftermarket gaskets are fine, as long as they are made to specs. They're "just gaskets," not complex pieces of engineering. I haven't heard of Seiko using special material to make their gaskets - its all about the proper shape/dimension/size. (Wouldn't using NOS 6309 gaskets from the '80s be questionable?...Rubber does deteriate over time doesn't it? Maybe an engineer or chemist can jump in a give their insight.)

I have pressure tested watches with aftermarket gaskets all around, and they consistently pass to 150m with flying colors. However, with that being said...if you buy gaskets off the bay or elsewhere on some random vague internet site, and the caseback gasket is skinny as heck, not uniform in shape, or overall ratty...then commen sense dictates that you don't use it. Some aftermarket gaskets just don't quite fit properly, which causes them to pinch or not seat, which then causes a weakpoint in the integrity of the watch. A lot of reputable watch dealers will pressure test a watch for the owner's peace of mind, however will not provide a guarantee of "water-resistance" due to the possibility of the owner cross-threading the crown when re-sealing it after setting the time, or just plain not tightening it down enough before jumping in the water. My .02

Sonny, you made very good and valid points, there.

About the 80's gaskets I have wondered exactly the same, myself. How come a NOS gasket be better than a brand new aftermarket gasket made to 1:1 specs? That's beyond me......judging by what happens to regular rubber straps that age with time, it only makes sense that the same will happen to rubber gaskets since they are made from the same material, right?

About SEIKO utilizing any special materials to make their gaskets, I have read on the old SCWF an extensive debate over this. I know for a fact that at least for the tunas, seiko used some kind of chemical compound called L-Buta to concot it. Experts always say that thanks to the tunas crystal gaskets being made from this special rubber, the need for built in He valves are not necessary. This special gasket compensate the variations in built in pressure due to penetration and exit of He molecules. It's reported that no other ordinary gasket would be capable of this performance.

About watchmakers not assuring water resistance due to the possibility of the watch owner not screwing down properly the crowns, I have read here extensively that screw down crowns are not responsible for ensuring water tightness, but just to better secure the crown to the watch's case in order to protect it against hard knocks to hard objects during diving and risk ruining the watch and in turn, the diver's life (this prior to the advent of dive computers).

Just a few points I found interesting adding my own $ 0,02. I'm sure I can be off in some of them or even all of them, though. This is a nice thread, by the way. This topic has always fascinated me. I regard water tightness one of the most fascinating complications a watch can offer. Just my humble opinion....

 

[skx]

I have had a bad experience with aftermarket case back gaskets. I think the trick is to look at the cross section. The good gaskets are round, the bad are flat. But I'm sticking to the real ones as long as they are available, and they are for all divers back at least to the 6105.

 

[water70proof]

Aftermarket gaskets from Jules Borel and Otto Frei appear to me to be the same as the OEM Seiko gaskets. There was an improvement in materials (maybe in the '90s? -- I can't recall the details...) that extends the service life of the newer ones. In that case, a new gasket, whether Seiko brand or not, would be preferable to a NOS example from the '70s or '80s. I've been replacing stem and caseback gaskets in my divers myself for several years, and then diving with the watches with no issues (longest set is now 3 yrs. old - I'll probably change them at the end of the year). I don't have them with me, but I think the divers take a .9 (thick) by 31 ID gasket (someone please correct me if I'm wrong). Still, the Seiko diver gaskets are only $2.30/ea from Borel if you order three or more, so it's not expensive just to stick with them.

 

[water70proof]

Just to clarify, SKX: Someone did a poor job if they replaced a Seiko diver gasket, which is always round in profile, with a flat one. However, many, many watches (including a lot of Seikos) are made to take flat gaskets, so flat isn't bad. It just depends on what the case is made to seal with.

I have had a bad experience with aftermarket case back gaskets. I think the trick is to look at the cross section. The good gaskets are round, the bad are flat. But I'm sticking to the real ones as long as they are available, and they are for all divers back at least to the 6105.

 

[Isthmus]

About SEIKO utilizing any special materials to make their gaskets, I have read on the old SCWF an extensive debate over this. I know for a fact that at least for the tunas, seiko used some kind of chemical compound called L-Buta to concot it. Experts always say that thanks to the tunas crystal gaskets being made from this special rubber, the need for built in He valves are not necessary. This special gasket compensate the variations in built in pressure due to penetration and exit of He molecules. It's reported that no other ordinary gasket would be capable of this performance.

Your are remembering correctly. The L-shaped crystal gaskets on Tuna Cans and on other watches like the Marine Master, are indeed made of a special compound and are unique to seiko. They don't prevent Helium intrusion though, but they do reduce it to a minimum. IIRC there have been some extensive posts by Pin Guan Pete about this in the past, I just don't remember which of his old names he used when he wrote them.

 

[otherjohnuk]

In a nutshell:

If the aftermarket gaskets are the correct size/shape they will seal the watch for swimming.

I have both Seiko and aftermarket and there apears to be no difference other than price.

OtherJohnUK