Reply With QuoteIts not water you have to worry about, its the devil child trying to steal your watch!!!!
Thank God for the 300m water resistantance and really don't know what I'd do if it wasn't for the He escape valve!
What pics do you have of pushing your watches to their extremes?
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Its not water you have to worry about, its the devil child trying to steal your watch!!!!
They haven’t made the watch that’s child proof yet
That must be why I can't find a watch with a drool resistance rating!Originally Posted by RustyBin5
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How about commercial diving with a non-diver rated mechanical chronograph during last weeks rather inclement weather...
Oh dear, my hot tub dip seems a little underwhelming nowHow about commercial diving with a non-diver rated mechanical chronograph during last weeks rather inclement weather...
What was the watch, and more importantly, did it survive?How about commercial diving with a non-diver rated mechanical chronograph during last weeks rather inclement weather...
I’m guessing this one.
https://forum.tz-uk.com/showthread.p...Field-Engineer
that's the one, serial number 000. This thread was just way too tempting not to put the pic on it!
Incidentally, a hot tub is way more dangerous to any watch, ever a diving rated one, than a bit of seawater as hot water expands the crown ever so slightly faster than the watch case and momentarily loosens the sealing. Even worse is if you put soap or bubble bath in with it as the lowered surface tension allows water to penetrate more easily. Come to think of it though, putting bubble bath in a hot tub would cause a few non watch related issues!
Rubbish!.......do you actually believe this?
The elasticity of the crown seal will cope with the infinitessimal effect of differential expansion between case and crown.
The surface tension effect upon the water is only an issue if the sealing is absolutely on the margins of efficiency.
I listened at school in science lessons, even ended up making a career of it.........also learned how to fettle watches in later life.
At the risk of needlessly flaunting my medals I think I’m fully qualified to say that you’re talking bollocks.
Paul
I'll start with a smiley face, just to show that comments like this don't bother me :-) and I'm an easy going person.
I think though that you should needlessly flaunt the medals you refer to, because then I can needlessly flaunt my technical qualifications, which include one of just 68 registered and accredited subsea engineers in the world, double chartered, degree, numerous technical papers, etc, and then I can needlessly flaunt my experience from 30 years of professional subsea engineering, and finally needlessly flaunt the rather extensive development and testing I did on the Field Engineer casing before putting it into production.
You're being somewhat aggressively dismissive (touch rude to be honest), based it appears solely on what your school science teacher said. I'd also suggest that you're actually wrong. I shan't go into why you're wrong because it's far too much hassle and involves Bernoulli equations, Reynolds numbers, the mathematics of slick-water as applied to hydraulic fracturing and then the difference between theory and engineering reality, none of which I think are on the school science agenda, so you go ahead and wear your watch in a nice hot soapy bath, and report back in a suitably smug way that it didn't leak.
Edit: three crown seals on the Field Engineer as there are 6 degrees of freedom, and just to reiterate that I don't want to be dismissive etc as everyone's comments are valid, but just occasionally uncalled for rudeness requires a response.
Last edited by LorneG; 26th September 2018 at 09:03.
Ouch!!!
I've no intention of derailing what could be a good thread, but I'm happy to report back that I've worn many watches in hot and soapy water as well as in jacuzzis (latest one last weekend PRS-3LE) and none of them have ever leaked.
Moving on, camel-testing: AFAIK there's no ISO/TC 114 for this.
R
Ignorance breeds Fear. Fear breeds Hatred. Hatred breeds Ignorance. Break the chain.
That's it, I'm getting a Ploprof for doing the washing up now!
M
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Breitling Cosmonaute 809 - What's not to like?
Don’t I know it. All the amazing watches out there. Yet an 18month old can easily render them useless!
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I still contend the Professor is mistaken......even though he's got lots more medals than me. Benoulli equation and Reynolds numbers are totally irrelevant in the context of a watch and whether it seals, he knows that but he's guessing (wrongly) that I don`t know what these terms mean.
Could the expansion of the crown really be sufficient to upset the sealing?.......show me the calculation to prove or disprove it, it'll save me doing it myself. It's an interesting point and it's one most of us wouldn't consider, but my gut feeling still says it's bollocks unless the seal is in poor condition and has totally lost elasticity.
I`ll dig out a dive watch with screwdown crown, make the appropriate measurements, then see whether the Prof's contention holds water if you'll pardon the pun.
On something much larger than a watch I'm sure he's right.......but it's all about context.
Anyone know the coefficient of linear expansion for 316 stainless steel and neoprene rubber off the top of their heads
42
Anyone know the coefficient of linear expansion for 316 stainless steel and neoprene rubber off the top of their heads
There is clearly some good technical knowledge and experience amongst the contributors to this thread so it's a shame the tone has dropped almost to the level of bickering. Just my two pence worth on the waterproofing issue - I think we'd be talking about volumetric expansion rather than linear and, factoring in expansion of the seals themselves, my educated guess (and it's only that) would be that the effects of warm or hot water would be negligible. It's an interesting idea to consider though. Jumping into an ice bath after a sauna could be equally risky?!?
Lovely looking watch by the way :0)
Just to mention that my work watch can go from hot to cold water (30c difference) and I have never had a leak, likewise it's been in steam rooms then out in the cold, it's never leaked or steamed up.
mike
WRT coefficient of thermal expansion, then you can only apply it once the material has had some heat added to it. Imagine the crown with the seal (or seals) sitting nicely recessed inside it. In order to thermally expand the seals you need first to heat (and thermally expand) the crown. In order to put numbers and mathematics to the issue you'd need to do it in a time-domain and account for the far greater thermal conductivity of steel to rubber, which becomes altogether too much for my simple calculations and requires the likes of the Deep Thought supercomputer. Mind you, it might come out with, "What do you get when you multiply six by nine", for which the answer, as Mr Tetley correctly points out, is 42.
Having identified that sudden hot water immersion might present a problem to a floating crown, and identified it was quite a tricky mathematical problem that I didn't fancy doing (building watches after all being a hobby), I moved onto some testing and simply plopped a case-crown into cold water, hot water and hot water with detergents and oils added, all at a reasonable pressure. Standard watch pressure testing machine with a plonger to immerse it, but need to pump the pressure up quickly as things start to warm up when suspended above hot water. My conclusion from all of this was a floating crown is an ideal solution on the field engineer (better shock resistance) and pretty darn good at water resistance, but on balance it's best not to wear it in the shower.
'prof' and 'bollocks' are being a little rude again, but in the interest of good manners I'll ignore it and wait with baited breath for your measurements. What do you plan on measuring?
Good to see you googled bernoulli equation and reynolds numbers. :-)
well this thread is a rare breed. Educational and entertaining in equal measure! I find the debate fascinating although with temerity I would suggest the risk although present may be minuscule given my rather frequent visits to the hot tub with my watch on with no issue. Middle ground anyone?
I'm with you
Hot tub water is usually only about 36-38 degrees
I've taken my Sub in the Maldives and the Red Sea (and dived to 4 Atmos for a bit of extra pressure) when the water is 30 degrees so not far off a hot tub temperature and I didn't expect it to leak and it didn't, a hot tub is hardly boiling water and I really wouldn't be worried about wearing a diver rated watch in one. They aren't soapy either the water is much the same as a swimming pool.
I would contend 30m of water pressure puts far more stress on any seal than 38 degree water.
I've worn my Daytona that's 10 years old in a hot tub for about 3 hours in the Summer, no problems.
I think Tokyo Tokei wins this thread anyway, Genius!
Last edited by Vanguard; 26th September 2018 at 15:18.
I’ve now given up wearing my Field Engineer in the shower
Reverted back to my trusty Milgauss GV and Seiko Samurai Save the Ocean.
I must add never worn a watch in a hot Bath.
But do shower and swim in them. (Sea & Pools)
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Are some people really saying that many really high quality manufacturers would have designed watches that are WR to 100, 200, 300+m without considering that they might be used in hot-tubs, baths etc?? When one considers that only a tiny proportion of people who own such a watch would actually use it for diving, it seems most likely that bath tubs and hot showers are the most likely situations a watch will get wet. Also, I'm sure the possibility that they might get soap on them (gasp!!!) will not come as a total shock to manufacturers.
+1, and not so sure you'd want to put bubble bath in a hot tub or jacuzzi - awful lot of bubbles
I think we were discussing the differences between a floating crown, which I personally don't think is suitable for diving or hot showers, and a screw down crown, which I think is OK for such things. Not entirely sure what we're discussing now.
Well this post went off on an unexpected tangent. Lol
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Still waiting for the nipple pic to end this thread
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Last edited by Yorkshiremadmick; 27th September 2018 at 12:53.
Benoulli? Reynolds? All I can say is the water was hot, she got soapy and my watch is fine
Last edited by peedog; 26th September 2018 at 17:02.
https://www.engineeringtoolbox.com/l...ents-d_95.html
…. and the calculation comes out that the crown expands by 0.1 to 0.2% when suddenly immersed in hot water.
Consider though the unfortunate chap who’s watch has manufacturing tolerances on the crown and tube at each end of their range. Few years old so its had times and dates adjusted a lot, and its been wound up bit, and the rubber seal has worn to an almost non-compressed level. (just to slip in a bit of marketing, the third seal in the field engineer disconnects when you pull the crown and the watch winds itself up like all automatics do, so sealing should be good for many years).
Now the chap jumps in the shower and whilst doing so those soapy and rock hard nipples so nicely shown below bump against the crown. Floating crown, so it flexes a little, low surface tension water (‘cause she’s got a lot of shower gel all over her and a scrubbing brush for you to do her back with) and 20 minutes later, whilst you’re both applying liberal amounts of Johnson’s baby powder and having a post shower cigarette, you notice a little misting on the inside face of your watch. Damn, you think, bloody watch wasn’t even pressure tested, and all your happy thoughts of a few minutes ago are gone.
So why not just have a screw down crown and not have any worry about this? Well, and at the risk of someone starting off on impact energies, a screw down crown annoyingly completes a nice solid load path from the outside watch casing to the heart of the movement. Floating crowns don’t do this and in my experience, I’ve knocked and dropped my watch far more than I’ve showered or dived with it.
Last edited by LorneG; 26th September 2018 at 16:56.
General part of the forum open to all so be mindful of kiddy-unsafe-pics.
Ah good point, amended
Not sure why you would even think that appropriate on this thread, keep your sh1t in boys room.
Mate, I was a qualified industrial chemist and I also studied process engineering. I worked with materials engineers, mechanical engineers, the lot, and it's fair to say I learned quite a bit. Please don`t be so patronising.
I left the industry almost 9 years ago, retired at 52, and entirely lost interest in chemistry/ science in general.
Anyhow, we're looking at a scenario where the crown heats up significantly faster than the seal or the pendant tube, and whether this can cause the seal to be compromised. Forget your clever maths and your thermal conductivity , lets skip straight to a worst case assumption and see what the numbers tell us.
Lets assume the water in the tub is at 45°. Lets also assume the watch has been outside on a cold day and the crown's at 5°C. Lets assume the wearer jumps in the hot tub wearing it. As for the watch, we'll consider a typical waterproof crown containing an O ring that slides on a smooth pendant tube. The O ring has to seal on both the inside and outside surfaces and owing to its elasticity it's under tension in a groove. A typical O ring will have dimensions of 3.8 x 2.5mm (wall thickness 0.65mm) and I estimate that it compresses to 0.55mm when it's located in the crown. The groove it fits into has to have a diameter of 3.6mm,and typically the walls of the crown will be around 1.0mm.
As a worst case, excluding the effects of thermal conductivity, the crown reaches 45° whilst the seal remains at 5°C. Does the crown expand sufficiently to leave the seal under zero compression? It approximates to a 5.6mm cylinder with wall thickness of 1.0mm and an internal diameter of 3.6mm.
For the seal to fail that diameter needs to reach 3.8mm, and with a temperature change of 45°C I don`t see it happening Here's why: Based on the coefficient of expansion for 316 stainless I estimate the internal diameter to increase from 3.600mm to 3.603....and that's a long way from 3.80! I dug out a formula for calculating the change in diameter of a thin-walled cylinder, got to confess I don`t carry this around in my head!
I think we're all agreed there's a large safety margin here. Any changes along the length of the crown won`t affect the sealing unless the crown relies on a flat seal placed it the end and it's screwed down, but even then it's highly unlikely.
The dimensions I`ve quoted are from a real-life example I`ve worked on and replaced O rings...........I`m not making this up! Also, in a real life situation the pendant tube will be heating up at a finite rate and the crown won`t uniformly reach 45°C instantaneously. Thermal conductivity of rubber is far lower compared to metal but any changes in temperature to the seal will cause it to marginally expand anyway.
Looks like my gut feeling was correct after all.
Paul
Last edited by walkerwek1958; 26th September 2018 at 18:58.
My turn to bite....
That's why they have a 'clutch', the spring compresses, the stem and bottom part of the crown are then not directly connected to the case.
Prof’s moved the goalposts by referring to watches in poor condition, if the seals are old they may have lost elasticity and become worn from winding the crown.......basically all bets are off and the watch won’t need much persuading to leak. I also think he’s overstating the surface tension effects too; if a watch will only just manage to keep clean water out but succumbs to soapy water then it’s in poor condition. The effect of temperature in the hypothetical hot- tub will reduce the viscosity of the water significantly and that won’t help either if the watch is in poor shape.
I think I’ve worked through the numbers, making appropriate estimations, with sufficient rigour to prove that a watch in decent condition that’s designed to be waterproof won’t suffer seal failure as a consequence of crown expansion, on that basis I rest my case.
To get back to reality, I’m not a fan of wearng watches in showers, baths or hot tubs etc. Many of my watches are vintage, even though the waterproof ones would probably be OK ( I’ve worked on them all) it’s a habit I don’t intend to get into.
One of the biggest hazards to watches thesedays is the hard floors that we’ve all started using. It really is a case of ‘ the bigger they come the harder they fall’, big heavy watch hitting solid tiled floor often ends badly.
Brilliant..............laughed so much I almost shat myself when I saw this
Paul, Nice reasoning and a good set of calculations, but don't you think my boob joke real life scenario is closer to the truth? It bears out under the testing I did and confirmed my suspicion not to rate the field engineer for anything other than swimming.
me32dc: The 'clutch' you talk about doesn't really exist and extensive drop and impact testing showed I got a far higher impact performance with the floating crown under all scenarios except the one where it lands with a glancing blow on the crown. Sod's law of course means...
You seem to have some engineering knowledge but just throwing in a couple of terms relating to fluid flow predictions when discussing temperature effects on crown and seal expansion just makes you seem like someone covering up their lack of knowledge with a few buzzwords.
If you're finding your engineering theory does not agree with reality, then there is a problem with your engineering analysis - usually this is because you have neglected some aspect that you thought was unimportant.
What do you mean here and how do your three seals deal with the three translation and three rotation d.o.f? Or, buzzwords? I can assure you that I can follow anything you would like to explain - I'm an ex Chief Engineer in the aerospace industry with 40 years experience.
Putting aside the sealing issue which you are discussing with Paul, your thoughts on the screw down crown transmitting shocks directly to the movement are wrong, I'm afraid. I would be interested to know how you measured these forces being applied to the movement in the two configurations, if you feel like explaining. Strain gauges are tricky to get right and a specialized subject in their own right.
Regards, Chris
Vostok designed a crown and stem assembly with an integrated clutching mechanism specifically to avoid shocks being transmitted to the movement via the crown.
You should tell my Seiko BFK Kinetic that has been put in the dishwasher, thrown in with the washing up, and put in a zipped pocket & put through the washing machine on many occasions.
I have been trying to kill it for 6 years now, but just emerges shiny and new every time … as well as fully wound!
Indeed, and a flanged caseback with separate fixing ring to allow a much wider sealing area, thereby reducing the impact of any temperature differentials and improving sealing as external pressure increases.
Indeed! The lack of hot tubs and bubble bath in the Soviet Union did make the whole Amphibia exercise seem a bit pointless though.
Handy for espionage missions into the decadent west though comrade. Jim Banana might never have met Olga Pushova in the jacuzzi if she hadn’t been issued with an Amphibia. 🤫
Laughed out loud for the second day in a row on the forum.
Well Paul, Lorne, can you use the Bernoulli effect to explain what happens next?
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