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Speedmaster remains airtight when the crown is pulled out?

Stas
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I got a tritium Speedy Pro '98 which was serviced about a year ago and according to watchmaker should be water proof.

Could humidity from the air enter the case when the crown is pulled out to set the time? Or the case remain airtight to some level?

I'm asking because the hands are perfect now and I want to avoid them to get dark spots over time like you see on most of the Speedmasters from 90s. Some summers it goes up to ~ 70%RH indoors here. I use dehumidifier at home, but conditions are far from perfect when traveling for a long time etc.

I appreciate if someone with the knowledge of the case construction and experience could answer.

Thank you
 
ObrWatches
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In this case storage is key. Maybe you have a safe place far from sunlight, you can take a watch sleeve for additional protection. Even though your watch was serviced its not water proof hence there are no screw down pushers.
Why would you store the watch with a pulled out crown?
Enjoy it in good health!
 
Stas
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ObrWatches WatchHeaven44
In this case storage is key. Maybe you have a safe place far from sunlight, you can take a watch sleeve for additional protection. Even though your watch was serviced its not water proof hence there are no screw down pushers.
Why would you store the watch with a pulled out crown?
Enjoy it in good health!

Sorry if my description was confusing. What I mean is: Could humidity from the air enter the case when the crown is pulled out during the event of setting the time?

I store the watches in protective cases and never with a pulled out crowns. But when you wear the watch during the humid months and have to pull out the crown to set the time and well, operate the pushers sometimes, can the humid air enter the case and stay trapped in?
 
Donn Chambers
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If your watch passed the pressure test, then yes, it will be fine to pull out the crown and change the time.
 
Stas
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Donn Chambers Donn Chambers
If your watch passed the pressure test, then yes, it will be fine to pull out the crown and change the time.
Thank you!
 
Pvt-Public
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Stas Stas
But when you wear the watch during the humid months and have to pull out the crown to set the time and well,
My god how long does it take you to set the time?
 
Archer
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Stas Stas
I got a tritium Speedy Pro '98 which was serviced about a year ago and according to watchmaker should be water proof.

Could humidity from the air enter the case when the crown is pulled out to set the time? Or the case remain airtight to some level?

I'm asking because the hands are perfect now and I want to avoid them to get dark spots over time like you see on most of the Speedmasters from 90s. Some summers it goes up to ~ 70%RH indoors here. I use dehumidifier at home, but conditions are far from perfect when traveling for a long time etc.

I appreciate if someone with the knowledge of the case construction and experience could answer.

Thank you

Perhaps some images will help illustrate. This is a Speedmaster case, and I have placed an O-ring, similar to the one that is inside the crown, onto the case tube. This is the approximate position that the O-ring located when the crown is pressed in to the winding position:



This photo represents the approximate position of that same O-ring, when the crown is pulled out to the time setting position (as you know, the crown does not move very far when it is pulled out):



Based on this, it should be pretty obvious that the water resistance does not change by moving the seal a couple of mm's.

Cheers, Al
 
Dan S
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It is water resistant but I don’t recommend setting watch in the shower.
 
Pastorbottle
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So long as you don’t decide to adjust the time whilst under water you’ll be fine. As Archer pointed out the sealing ring stays on the case tube the whole time.
The only way that I can see that it might let some water in (and I’m talking about a minuscule amount) would be if you were to move the crown whilst submerged….. maybe just maybe you’d be unlucky enough for the smallest amount to get in if the seal rolled as it moved.
Having said that it is always going to seal better with the crown in. This is because the seal will be slightly compressed between the crown, the case and the case tube. In other words the seal is fully supported at all points when closed and it will have one side not supported when out.
Only likely to make a difference under pressure, and/ or with a worn or hardened seal.

Come to think of it, I must get around to doing the annual pressure test fest!
Where I dig out he whole collection and pressure test the lot.
I was fortunate enough to be given a Witschi Proofmaster pressure and vacuum tester a few years ago, so it’s easy for me to monitor the whole collection.
Edited:
 
Archer
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Pastorbottle Pastorbottle
Having said that it is always going to seal better with the crown in. This is because the seal will be slightly compressed between the crown, the case and the case tube. In other words the seal is fully supported at all points when closed and it will have one side not supported when out.

This is not true...the O-ring is supported the same no matter if the crown is pressed in or not.
 
Dash1
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Archer Archer
This is not true...the O-ring is supported the same no matter if the crown is pressed in or not.
I’m just wondering, can the o-ring be replaced on an old crown, or is a new crown required?
 
Pastorbottle
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Ok so when the crown is in the seal touches at 4 points…the top of the crown, the sides of the crown, the case tube and the boss of the case.
But when it’s out it only touches at 3 points…… the top of the crown, the sides of the crown and the case tube but not the case boss.

Now I know that you’ll forgotten more about watches than I’ll ever know, but what I said was based on my years of experience with hydraulics and pneumatics where the more supported the seal the better it works and the longer it lasts.
 
Wryfox
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Waterproof is not the same as airproof. You need a much tighter seal to stop a gas. That being said, the flow of air possible (given there is a compressed seal in the way to greatly inhibit it) during the time you are adjusting the watch, is academic. All other things being equal, the flow would be dependent on the difference in pressure between inside and outside air. Theoretically it could be up to 10% pressure differential depending on barometric pressure, or more if you're standing on a mountaintop🙄

I think the question was asked with the visual of a rubber stop inside the crown, such that unscrewing the crown releases the seal from contact with the tube edge, creating an opening to the atmosphere. Its a fair thought, and it IS how some crowns seal. My Breitling Superocean is both a rubber stop AND an o-ring.
Edited:
 
Archer
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Pastorbottle Pastorbottle
Ok so when the crown is in the seal touches at 4 points…the top of the crown, the sides of the crown, the case tube and the boss of the case.
But when it’s out it only touches at 3 points…… the top of the crown, the sides of the crown and the case tube but not the case boss.

Now I know that you’ll forgotten more about watches than I’ll ever know, but what I said was based on my years of experience with hydraulics and pneumatics where the more supported the seal the better it works and the longer it lasts.

Well, being an engineer and having done lots of hydraulics and pneumatics in my time (including hydraulic actuators that were 3 feet in diameter), I fully understand your point completely. But the O-ring is not free at the opening of the crown as you imagine it to be, and it doesn't make contact with the case at all. So it gets no more or less support if it is pulled out or pushed in.

Here is a Speedmaster crown installed on a case tube...this should clear up your misconception...



Cheers, Al
 
Pastorbottle
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Thanks for that, sitting here at work without a suitable Omega to use as a visual reference.
 
Archer
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Dash1 Dash1
I’m just wondering, can the o-ring be replaced on an old crown, or is a new crown required?

Yes and no. Some crowns are designed so that the O-ring is easily replaced. Most of Omega's screw down crowns are this way, where I can simply go in and pull the O-ring out with tweezers or using a small pick (made from a broken oiler).

For the type of crown that is typically used on Speedmasters, it's not that simple. Here's what a worn out seal in a crown looks like:



As you can see there is a post coming up the middle of the crown that the stem screws into. The O-ring is under that washer, which is swaged in place, so to replace the O-ring there are 2 possible paths. One is if the O-ring crown section is smaller than the gap between the post and the washer, you can dig it out and push a new one in without fear of damaging the O-ring in any way. This assumes that you have the correctly sized replacement O-ring. Omega does not sell O-rings for these crowns, because they are not meant to have the O-rings replaced.

Now is a good time for a word about old O-rings. They have several stages of death. The first is loss of elasticity - they would be easy to remove at this stage. Then things get steadily more difficult, so you have serious hardening of the O-ring - honestly sometimes these are so hard you can only chip them away...like this one on a case back:


I can't imagine being able to remove these from a crown very easily just by picking them out. Then they turn to black goop, so the only way to get them out is solvents, and you would have to be 100% sure you got it all, because if you don't, then you could be compromising the water resistance of a new seal. Then if they last through the goop stage, they become like hardened bubbly black glass, and are even tougher than the video above to remove.

The second way would be to remove the washer, remove and install the new O-ring, then install the washer. I'm sure in this discussion someone will post the link to the Seiko crown where the guy stuffs a bunch of O-rings into a crown to force the washer out, replaces the O-ring, and manages to get the washer back in. So yes, it can be done - is it anything I would offer any sort of guarantee on? Not a chance.

I hear of people saying it's easy and they do it all the time, but whenever I've asked those people to tell me what size the O-ring is that they use as a replacement, I never get an answer...perhaps one of the people who say it's easy could start a business restoring vintage crowns - I'm sure they would make a killing doing it, but it won't be me...😉
 
Stas
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Oh thank you so much! Especially @Archer for your professional experience!
 
SC1
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Personally I am nominating Al @Archer for a Nobel Prize for Tolerance...

the sheer amount of time that guy has had to, been compelled to, requested to, dared to, "prove it to me" to'd, PSA'd to, cajoled to/into -- and almost always with the patience of a saintly grandfather -- about all the fine points of water resistance, while dispelling the endless amount of myth/static/spin/mis & disinformation/and outright bullshit, makes my mind spin.

Al, you deserve more than a mere Thank you Again but it's the internet so -- thank you again sir.
 
Archer
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SC1 SC1
Personally I am nominating Al @Archer for a Nobel Prize for Tolerance...

the sheer amount of time that guy has had to, been compelled to, requested to, dared to, "prove it to me" to'd, PSA'd to, cajoled to/into -- and almost always with the patience of a saintly grandfather -- about all the fine points of water resistance, while dispelling the endless amount of myth/static/spin/mis & disinformation/and outright bullshit, makes my mind spin.

Al, you deserve more than a mere Thank you Again but it's the internet so -- thank you again sir.

I'm an atheist, but if there is a hell it would be having to debunk water resistance threads on watch forums constantly...wait a minute!!!

😉
 
Dash1
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Archer Archer
Yes and no. Some crowns are designed so that the O-ring is easily replaced. Most of Omega's screw down crowns are this way, where I can simply go in and pull the O-ring out with tweezers or using a small pick
Thank you so much for the detailed response. Very interesting.
 
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