Jaeger-LeCoultre

a reverso in SS case stated 5atm with an articulated rubber bracelet is supposed to be water friendly.

would u want to wash it under running tap? note there isn't any sophisticated protection to the crown.

really appreciate your opinions! thx all experts!

Have in mind the the 5 AT are ok if you don't forget to check the etancheity joint each year, my friend, as for every watch.

In this case, yes, I will be confident in thre water resistance of your Reverso.

Don't forget that 5 AM don't mean that you can swim with your Reverso, it is water resistant for a shower, but not for a swim.

Welcome here, By the way!

Best.

Nicolas

i guess i can simply enjoy showering with it until i need a check in a year time!

btw, nicolas, i love reading ur posts all the time even during at work!

Thanks, my friend, for your nice words, and enjoy your new Reverso.

Any pic of the new Baby?

Best.

Nicolas

... about the swimming and showering. Whats 5 AM and 5 AT? Isn't 5 ATM, the equivalent of 50m water resistant?
Tnx.

Karim

I wouldn't take any watch swimming or otherwise unless it had a rating of 10atm (100 meters). To my mind 5atm means splash proof.

I would also be wary about taking any watch, no matter what the rating, to take a shower. Showers=hot steam and soap... two enemies of any water resistant sealant.

Or is that only the case for 5atm Master Control watches, and not Grand Sport Reversos? That cannot be true--5atm is 5atm, and JLC says swimming is fine, but not diving or other water sports.

DJK

When you swim, you have pressure wth your arm " breaking " the water...

This pressure may go above 5 ATM.

If you want to swim with a watch, it is traditionnaly recommended to get a 10 ATM Watch.

Best.

Nicolas

It is impossible to move yours arms with the necessary velocity to increase the pressure in any meaningful way. This is why swimming is absolutely fine (and the JLC manual *says* that swimming is safe for watches with 5atm WR). I would not worry at all about swimming with any JLC rated to 5atm, and happily wash them under a faucet when necessary. I trust JLC would stand by what they recommend in the manual.

DJK

Have you tried swimming with a watch rated at 5atm with no screw down crown or compressor key? You're a very brave man if you have.

regards
Bretta

My Master Hometime got wet regularly (5atm) and I didn't worry because JLC indicated in the manual that it was fine to swim with the watch. I had no problems. I also got my RGM (no screw down crown, rated to 5atm?) regularly wet giving my son a bath. There was soap involved as well, and I do the same with my Stowa FO LE (no screw down crown, rated to 5atm).

I won't consider buying a watch that I must worry about immersing. Because 5atm is sufficient for swimming, I have no worries about getting such a watch wet under any conditions, and I'd happily swim with one as well (just don't have that many opportunities to swim, to be honest). And I am encouraged not to worry about it because JLC says it's fine.

At the end of the day, it doesn't matter what sort of advice is given in this thread because JLC has already answered the query by explicitly addressing it in the manual. I just wanted to point out that the advice given here is considerably more conservative than JLC themselves provides.

FWIW, a screw-down crown does not provide any WR--WR is provided by gaskets, not the screw.

Cheers,
Daniel

Hi Daniel,

If JLC says it's OK to swim with it, then so be it. For my part I won't swim with a watch without a screw down crown.

You're point about the speed of motion necessary to meaningfully increase the water pressure on the gaskets is well taken, but that's not really the primary concern when swimming with a watch without a screw down crown. The real potential for leakage is from the sideways pressure on the crown distorting the gaskets and compromising the water resistance on one side. You splash your arm vigorously or dive into a pool and the instantaneous pressure of the water on the crown can cause it to force the gasket to compress to one side and allow water to get in. This is why screw down crowns are considered to be more water resistant, because they are more deflection resistant.

The other key real world issue is the condition of the gaskets over time. Water resistant to 50 M when brand new is no guarantee of water resistance 3 yrs down the road. Get your wet-use watches water tested at least once a year!

_john

I have yet to see any sort of evidence that splashing one's arms vigorously will achieve the sort of pressure change necessary to compromise 5atm of protection--the math simply doesn't work out. However, it is always prudent to have WR checked once/year if planning any hydro-horological adventures.

Cheers,
Daniel

Hi Daniel,

Of course you're free to disagree, but your post didn't indicate that you had read or understood that I'm agreeing with you about the (negligible) pressure change resulting from the motion of one's arms, just pointing out that the force of the water in motion (drag) on the crown (or pushers) can cause substantial deflection of the components and compromise the gaskets even without exceeding their pressure rating. If you read the ISOs about diving watch testing, you'll notice that one of the tests involves water resistance while the crown and/or pushers are subjected to a perpendicular force. It should be noted that the JLCs in question are not of course diving watches so would not be tested in this way, nor would they likely pass without a screw down crown. I haven't seen any actual math in this thread thus far, but feel free to insert some if you'd like.

_john

I agree that arm movements associated with swimming would exert any troublesome pressure on the gaskets or the crown/pushers (is there a reason to think that the pressure one these parts would be greater or worse than the same pressure directly on the gaskets?). The ISO test you mention requires some additional pressure or leverage on the crown or pusher. One might encounter such pressure while diving and encountering rock or fumbling with dive gear. But it seems very unlikely, and therefore not a concern for testing, on a watch that is fine for swimming but not diving (as we can agree a 5atm watch is).

For a very long time (and perhaps still), many excellent dive watches did not have screw down crowns but were still ISO tested and approved to 150m.

Cheers,
Daniel

Hi Daniel,

Pressure with regards to water resistance can be thought of as consisting of static pressure (related only to depth (and minimally temperature)) and dynamic pressure (the additional pressure caused by motion of the fluid or an object in the fluid). Dynamic pressure in normal ranges of motion is basically neglible, being somewhere in the vicinity of 0.5 BAR at 10 M/s. We are in agreement that dynamic pressure is not likely to push the gasket in a watch beyond their functional limits in normal use.

To avoid further confusion, I'll call the thrid consideration I'm bringing to the discussion "drag related deflection". Any solid body travelling through a fluid will experience drag. The sudden experience of drag when crossing the air to water interface can be traumatic, as anyone who's ever performed a belly flop knows. This sudden drag imparts a force on the objects experiencing it and can cause them to move or deflect from their normal position.

When this happens to the crown or pushers of a watch, it can cause them to deflect to the side, compressing the gasket on one side while potentially compromising the seal on the other. This drag related deflection can cause the seal to leak at basically 0 meters depth if only for a moment (long enough to get water inside). In this instance, this drag is affecting only the crown and pushers directly because the gaskets don't have any interfaces with the water that are not "shielded" to some extent by the crown, tube pusher cap or pusher tube. It is for this reason that diving watches are tested with lateral force applied to the crown and pushers, not only in case they get bumped about by rocks and such.

I can't think of any modern diving watches that don't feature some kind of locking mechanism for the crown, and I don't know if the older dive watches you referred to might have predated the current ISOs. My opinion is that a securing mechanism of some sort is important to attain real world water resistance.

Anyway, sorry for belaboring this point so exhaustively. I am admittedly conservative when it comes to my watches and water resistance. I have a watch rated for 100 meters without a screw down crown and I won't wear it swimming. I've seen far to many watches that are rusted beyond practical repair to take water resistance for granted myself.

_john

I think this may account for the JLC recommendation in the manual against diving and other water sports. In any case, I found it interesting, so thank you.

Would you be similarly concerned about allowing a watch with 100m WR, a screw-down crown, and a chrono pusher get wet? As I understand it, most screw-down pushers merely lock the button to prevent compression, but do not accomplish any further WR protection. The example I'm thinking of is my MIH watch, which I plan to wear for most everything, including any swimming, fishing and beach activities. Any reason to be concerned about the 100m WR of that watch in those circumstances given the mono-pusher chrono?

Cheers,
Daniel

Hi Daniel,

The purpose of screw down pushers is the same as for screw down crowns: to stabilize the pusher so that the gaskets can't be disturbed and potentially compromised by lateral forces. Even the extensions inside the case that the pushers interact with will usually impart a little side force onto the pusher, so activating a pusher without deflection is a near impossibility in most cases.

The bottom line is always (as you mentioned) what does the manufacturer recommend? If the MIH folks say it's OK to swim with it, then presumably they know what they're talking about and will stand behind it if something goes awry. I personally would probably not, but as I said, I'm a little more conservative about water resistance than many.

_john

Pressure is force/area.

The force a pusher would see, therefore is the pressure muliplied by the area. What's the area of a pusher? What does this tell you?

Also your analogy of jumping into water: The force is you breaking the water surface tension. Nothing to do with the pressure at the surface, which is at atmospheric.

I think pressure rather badly understood. Mainly because to the human senses, it is mainly experienced as force. 

These threads remind me of automotive ones, where people claim that their car gets 20% more power at 150mph!

 

 

A simple question re: pushers. Why are non-screw chrono pushers not activated at depth? If there's enough "drag" to cause deflection of the stem then what about the static pressure inadvertantly depressing a pusher.

So, what is the force on the end of a pusher?

(now this is all done in my head, so I beg forgiveness if it is stupidly wrong)

Pressure=Force / Area.

50m=5 atm=5 kgf/cm^2 approx.

Area of pusher=(assume 4mm dia pusher) pi x r^2

using 3 for pi (I like simple numbers!) gives us: 3 x (0.2)^2=0.12

So back to P=F/A:

5=F/0.12

0.6=F

So at 50m there is roughly 0.6 kg (~6 N) on the end of the pusher.  And 50m is pretty deep.

(Out of interest, what is the force on the dial? if we assume 40mm dial: 60kg (~600N).... dare you stand on the dial?

I will do some delving in my old fluids texts for dynamic pressure to work out the sideways force on a crown. but the above gives the magnitudes of forces involved.

Something to dwell on.

Please comment on any of the maths or assumptions, all feedback is great.

 

This message has been edited by BDLJ on 2008-12-04 16:19:07

Lots of simplifications here, so bear with me.

I have simplified numbers so I can do them in my head and on the calculator in my mobile, so exact values are incorrect, but magnitude should be OK (and please correct me if I am wrong - I can take the embarrassment!)

If your wrist is moving through the water at around 20km/h (~5m/s)

Then the dynamic pressure is: P=0.5 x Density of water x velocity^2

So:   P=0.5 x 1000 x (5x5)

         P=12500Pa=~0.125 atm.

Radial force on crown: (I am simplifying the side surface of a crown from a curved surface to a rectangular cross-section, but this is a worst case).

So let's make the cross section largish 7mm x 5mm=35mm^2=0.35cm^2

P=F/A ->  0.125=F/0.35 -> 0.125 x 0.35=F=0.04kg OR 0.4N

Not much at all.

The ISO spec calls for a sideways nudge on the crown of 5N or the based on the above assumptions...equivalent of moving though the water at....around 60km/h...fast!

 

 

Hi BDLJ,

I don't have time to double check all the math, but it looks like you converted 35 mm to 0.35 cm instead of 3.5 cm, which could account for a significant difference in the outcome. You've ignored the drag coefficient also, but that would presumably lessen the resultant force by possibly half.

_john
This message has been edited by ei8htohms on 2008-12-05 02:41:49

7 x 5mm=35mm^2=0.35cm^2

It's the rest of the maths I'm not confident of!

 

nt

Hope I did not come across as a smart-alec with the maths. It's something I have heard and seen before, but never calculated myself. And we know stuff on the internet is not to be trusted ;-).

A question for you as a watchmaker who has opened far far far more watches than I:

All but a single watch that I have encountered that has demonstrated water damage has had water ingress via the crown. Not via the crystal nor the caseback. Does this tally with your experience?

And a last note on WR from my humble perspective.

It is completely unscientific and does not apply to all watches, but to a large degree, it is the intent of a watch that determines my bravery in wearing it in water. Take the case of a dress watch. Even if it is given a 30m rating, it is likely that the seals are not optimally designed, that is, the seals are there as an aid to the general longevity (dust ingress, splashes) of a watch, not to provide "fitness to purpose". They are likely to be very thin and fragile seals, that just happen to meet a test specification that rates them to 30m.

Conversely, a dive watch need not be of massive proportions to cope with the pressure. To me if a watch is sold a professional dive watch (not a 'styled' dive watch) then it should be capable of being worn on a dive on a daily basis, getting banged up and covered in corrosive salt, day after day. Oh and rarely serviced. It is in the interests therefore of the manufacturer to make something robust.

The depth rating, to my mind is relatively easy. All of which is cancelled out if the seals are shot, or pinched etc.

But in the end, I guess, it's economics. There are those that could afford to flood a $10K watch. I would not spend over a few hundred dollars (though that buys you some very very good kit) on a watch for dive back-up.

Hi BDLJ,

In truth, watches can leak from anywhere, and I've seen them leak through the crown, the tube, the pushers, the pusher tubes, the back gasket, the crystal gasket, the bezel gasket, the crystal itself (cracked or chipped) or even the case frame itself (corroded pores or half-assed diamond studding).

The crown is the most common culprit though because this it the one the user interacts with the most. Whether through leaving the crown unscrewed or pulled into setting position and getting when submerging the watch or simply wearing it out or damaging it in some way from use and abuse, the crown and tube are the most common failure points in my experience, but this really depends on the case design to some extent.

Some ultrathins will commonly flood around the crystal or the back due to the flexing of the case and many non-round cases will flood around the crystal or back crystal gaskets because it's VERY difficult to get a hermetic seal around a non-round crystal (glue helps).

_john

Hello Daniel,

Interesting topic and point of views. 

I think that ei8htohms might have some background and experience with watch water resistance testing.....  =)

But glad to hear that you are using the watch to the full potential.  Please let us know if there are any WR problems with your watches in the long term.

-MW
This message has been edited by DRMW on 2008-12-03 16:36:12

Some were only rated to ..oh dear..30m... Then there is the 200m Heuer without a ... gasp ... screwdown crown. And my 33 year old Seiko 150m diver that has been to at least 35m....without a screwdown crown!

If the seals are good, a watch should be able to do what the rating says.

 

Most of the Manufactures ecplain that it is not good to swil with a watch rated at 3 AT...

So, you would swim with, as it is expalined that at 3 ATM, this allows the watch to resist to spalshes, as when you wash your hands?

Me not.

Not with my MMR, which is rated for 5 atm.

But if you want to test it for us, I'd be happy to know that there is no problem with!

Best.

Nicolas