Obligatory Wristwatch Thread

[Wondering Beard]

Coincidentally wearing my Panerai today. It doesn't have a screw down crown, but it does have a cam lock mechanism that ensures the seals are engaged properly.

That cam lock is very cool and very ingenious.

IIRC, the Italian Navy's frogmen during WWII and just before needed a water resistant watch for their operations (which never went below 100m). Panerai, at the time, didn't make any watches, they just assembled them, so they asked Rolex for water resistant cases and they would make and assemble the rest of the components. This was the first iteration of what would become the Radiomir line (because it used radium for illumination). It was very well sealed but didn't use a screw down crown and wasn't automatic; as a result, it didn't take long for the seals inside the watch to need replacement. As this was mostly during war time, no money was going to be spent by the Italian gov't to make a better watch (and, I think, Rolex still held the patent on the double and triple lock screw down crown). After the war, to remedy the problem, Panerai invented that cam lock which really ensured the tightness of the seals and later made the movement automatic. That cam lock is now a Panerai signature.

[MountainRaven]

Let's put it in simpler terms.

Remember Todd saying something along the lines of "rare pistols are rare for a reason"?

It applies here.

None of the high end diver companies use a push pull crown, there's a reason for that.

For that matter, no door that is meant to be watertight sealed on ships and subs is push pull. There's a reason for that.

Both systems have seals (basically rubber gaskets that can be arranged in a simple or complicated manner), those seals get used up just by winding and setting the time. Push pull gets used up more easily than a screw down (cue Panerai from WW2). Plus a screw just closes down tighter.

So, while I imagine that a very well made push pull crown can work about as well as a screw down, most (which are produced by, let's be kind, "value" companies) are not.

Is the reason that you actually need a screw-down crown for a diving watch or because nobody would buy one because they believe they need a screw-down crown?

[Wondering Beard]

Is the reason that you actually need a screw-down crown for a diving watch or because nobody would buy one because they believe they need a screw-down crown?

Ask Blancpain, Rolex, Oris, Omega, JLC etc ….

They choose to make them the way they do,
And it seems to work well for them.

:-)

[MountainRaven]

Ask Blancpain, Rolex, Oris, Omega, JLC etc ….

They choose to make them the way they do,
And it seems to work well for them.

:-)

Well, Rolex makes all of their watches with screw-down crowns, including their dress watches.

[BillSWPA]

Well, Rolex makes all of their watches with screw-down crowns, including their dress watches.

As a result, people go scuba diving with Datejusts without problems.

[BillSWPA]

Is the reason that you actually need a screw-down crown for a diving watch or because nobody would buy one because they believe they need a screw-down crown?

I have owned several supposedly waterproof watches without screw down crowns, and with only one exception, every single one has had water leak into it. At least about half a dozen of them leaked the very first time I wore them to go swimming. The rest lasted about 5 years and then leaked water. Only one watch with a push-pull crown that has been exposed to water - a Seiko I bought my wife - has held up so far. I had the seals replaced in that watch once.

I have also owned multiple watches with screw down crowns and screw casebacks. Not a single one has ever leaked water. In one case, the watch successfully kept water out despite the seals being determined to be in very poor condition at a subsequent service. In two other cases, water resistance was maintained through multiple decades despite the seals never being changed.

I find it impossible to believe that my experience is unique.

Given that experience, why would I have any interest in a supposedly waterproof watch without a screw down crown?

[Wondering Beard]

Well, Rolex makes all of their watches with screw-down crowns, including their dress watches.

I’m not so sure. While I haven’t been able to find out precisely, the discontinued Cellini line only had a 3 bar water resistance )indicating the possible absence of a screw down crown, and the new 1908 is rated for inly 5 bar, so it could go either way.

You are right about the rest of the model lines, as all have a minimum of 10 bars so they all get screw down crowns.

Strangely enough, the part of your post about the ISO rating didn’t show up here but only in the email telling me about your response to my post. You are correct, the ISO does require a screw down crown and a few other things. However, when Blancpain and Rolex came up with the two first dive watches, the ISO didn’t exist yet, yet both still chose to use a screw down crown.

I imagine Rolex did so simply because they already had a patent on their variation, thus a strengthened and improved version of what they already had was simply cheaper.
Blancpain, on the other hand, having always been in higher luxury tier than Rolex, would have gone with what they considered the best technology (the bezel of the Fifty Fathoms being an example). So by choosing a screw down crown, they chose what they believed was the best technology.

At least, that’s what makes sense to me.

[MountainRaven]

I’m not so sure. While I haven’t been able to find out precisely, the discontinued Cellini line only had a 3 bar water resistance )indicating the possible absence of a screw down crown, and the new 1908 is rated for inly 5 bar, so it could go either way.

You are right about the rest of the model lines, as all have a minimum of 10 bars so they all get screw down crowns.

Strangely enough, the part of your post about the ISO rating didn’t show up here but only in the email telling me about your response to my post. You are correct, the ISO does require a screw down crown and a few other things. However, when Blancpain and Rolex came up with the two first dive watches, the ISO didn’t exist yet, yet both still chose to use a screw down crown.

I imagine Rolex did so simply because they already had a patent on their variation, thus a strengthened and improved version of what they already had was simply cheaper.
Blancpain, on the other hand, having always been in higher luxury tier than Rolex, would have gone with what they considered the best technology (the bezel of the Fifty Fathoms being an example). So by choosing a screw down crown, they chose what they believed was the best technology.

At least, that’s what makes sense to me.

The ISO/locking crown bit I edited out when I was unable to find anything supporting the requirement for a screw-down crown in a diving watch.

The ability of the crown to resist ingress of moisture at pressure is tested, either way, with the crown screwed in (if applicable).

I could verify this, if I wanted to spend something like 60 Swiss francs to download the actual ISO requirements, but... probably not worth it for random interweb posts. Maybe someone else will want to spend the money and find out for sure, though.

[Wondering Beard]

The ISO/locking crown bit I edited out when I was unable to find anything supporting the requirement for a screw-down crown in a diving watch.

The ability of the crown to resist ingress of moisture at pressure is tested, either way, with the crown screwed in (if applicable).

I could verify this, if I wanted to spend something like 60 Swiss francs to download the actual ISO requirements, but... probably not worth it for random interweb posts. Maybe someone else will want to spend the money and find out for sure, though.

Turns out I was wrong.

The ISO doesn’t require a screw down crown, at least in this article: https://www.watchtime.com/featured/d...water%20again.

[TOTS]

I bet that was cold. Is it all water intrusion or maybe some condensation?

Yup, a little nippy!!

I think it’s all intrusion. I threw it in a container with a ton of desiccant and the crown pulled for a couple of days. The next time I put it on, the heat from my arm caused the condensation on the inside to appear.

Regarding the above arguments about screw vs non-screw crowns… after this experience Im only looking for screw-downs. I have been swimming in pools, fishing, etc in this watch for about five years, though, so maybe it’s my fault?