Hm.. that prompts a question that's been on my mind for a bit - with renewing the seals/gaskets and application of a bit of silicon grease, what kind of waterproofing is being achieved? I mean, I don't suppose it'll ever have factory fresh waterproofing as spec, but with new seals and ensuring everything is nipped tight...?
Obviously pressure testing would confirm, but I can't see what else there would be to 're-proof' the watch other than seals and silicon - what do we think chaps?
Here are a few points to ponder, Howie. Water resistance is a dynamic state and depends primarily on the condition of the sealing surfaces (those surfaces which make direct contact with gaskets) and the sealing gaskets themselves (so the bezel gasket doesn't count in the 6309 diver's as it's job is to provide even friction when rotating the bezel). An obvious addition to this is the physical structure itself- you can't have a gaping hole in the side of the case or in the caseback. You can have all sealing surfaces in excellent condition, but with bad gaskets, the case may not be sealed. You can all have gaskets in excellent condition (i.e. "new"), but with bad sealing surfaces, the case may not be sealed. The extent of how sealed the watch is depends on how good of condition these components are, though typically if a watch does not pass at high pressure, it will not pass at low pressure, and vice versa. Not always, and especially less so with extreme pressures.
Another thing that comes into play is the mechanical fitment of the parts necessary for sealing- in the 6309 diver's this would be the crystal retaining ring and the case tube that is frictioned into the case. In order to make the tube as sealed as possible, Seiko welded it into place, so really one does not have to worry about water being able to enter between the case tube and case frame for this model- for all intents and purposes, it is like one piece. Not all tubes are like this from every watch company, so when doing water resistance maintance, very often the case tube should be reset. The crystal retaining ring can cause problems in achieving the best seal possible if it is no longer evenly tight- compressing the crystal gasket by pushing down on the crystal. Water resistance pressure and vacuum testing will verify the state of these elements as you mentioned, but these are static tests at a given point in time, they cannot say what the watch will do under
x conditions after
y amount of time.
Replacing all the gaskets is certainly the best thing to do for a watch that will be worn regularly- whether it is a diver's watch or not. Just doing this alone does not ensure the watch is water resistant- I've had a small piece of lint on the case back gasket cause a case to fail a pressure test- it was enough to allow air around it and inside the case when put under pressure. If any one is seriously considering using a watch in water after they've replaced the gaskets, it would be advisable to have the case pressure tested- for a small fee a local watchmaker should be able to take care of that if properly equipped. This is not a guarantee of water resistance, but does offer evidence that the watch is currently in a sealed state.
And a note about silicone grease I've been meaning to bring up- it has no magical restorative powers when it comes to rubber gaskets- it is a false economy to think silicone added to a gasket is just as good as replacing the gasket. It can help reduce friction of those gaskets which undergo frictional forces- bezel gaskets and crown gaskets for example. Everyone says to grease back gasket as well, but really this should be viewed as an action done to help in seating the gasket when tightening and loosening the back- to help keep the gasket in place and not be picked up in one spot or another as the back is tightened. In some case designs, it can actually make it harder to seat the gasket and get a good seal if silicone grease is applied to the gasket. Just a thought I've been meaning to put out there.
Well, apart from the case back gasket, there are the crown and crystal gaskets too, and I don't intend to change either, so personally I would settle for not-having-to-take-off-the-6309-when-washing-my-hands water resistance. But that's just me, I am comfortable with this kind of limitation.
Cheers,
Andrew, I'd suggest you rethink at least the crown gasket- the crown gasket is typically very old in 6309's that haven't been well-maintained (which ones have?) and falls into one extreme on the crusty-slimy scale. Being such a relatively small gasket (compared to the crystal gasket), and with the crown an attractive place for water to collect even from the occasional hand-washing, it can more easily allow moisture inside compared to the case back or crystal. Hand washing can be viewed as just as dangerous as diving to 150 meters (who does that anyways?) with a watch whose set of gaskets have not been replaced- it is typically the easiest for water to get past old gaskets with no additional outside pressure- which can act as a further seal. Watches are tested at low pressure and then high pressure for this reason. Then again, maybe you are a careful hand-washer, so that water does not have a chance to splash onto the watch case;-)
