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Thread: Is a watch that's water resistant also humidity resistant?

  1. #1
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    Is a watch that's water resistant also humidity resistant?

    Is a watch that's water resistant also humidity resistant?

  2. #2
    Master danmiddle2's Avatar
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    Quote Originally Posted by Tinker View Post
    Is a watch that's water resistant also humidity resistant?
    I can't think of any reason why not. Essentially humidity is also water and under way less pressure. I'd have to say yes, but not an authoritative opinion.

  3. #3
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    I can't see why not, unless it was sealed with some moisture present which then shows due to temp changes etc.

  4. #4
    Craftsman kinyik's Avatar
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    Yeah provided the seals are relatively new, I donít see an issue with that.


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  5. #5
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    I think the question is whether a watch can be watertight but not airtight? Seems a strange question to ask!

    If the seals are working correctly the watch will definitely be airtight.

    I suppose there could be a scenario where a seal isn`t able to keep air out but can just manage to keep water out. I`m thinking of a situation where a sealing surface is pitted and the seal can`t seat correctly, if the seal and sealing surface are hydrophobic (light covering of grease will achieve this) a drop of water at atmospheric pressure won`t be able to find it's way in, it'll remain as a droplet and won`t creep into the tiny gap. However, by reducing the surface tension of the water (a drop of detergent will cause this) it may well find its way in.

    As for the watch being sealed in humid air and subsequently being affected by condensation inside, I`ve tried to replicate this effect several times and never succeeded.

  6. #6
    Putting my engineering hat on - seals can need 'energising' so they may require pressure on them to activate fully and to hold pressure. So when you are testing the seals, you should do both a low pressure and a high (max pressure) test to truly see if the seals holds. It may seem odd, but in my experience low pressure tests can be harder to fulfil because of this 'energising' factor.

    Thinking aloud, it would depend at what pressure the watch is at. So in the case of humidity we're talking, atmospheric - so it could be possible, but I think that would also mean that the 'splash proof' of the watch would also be compromised(?).

  7. #7
    Master bedlam's Avatar
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    Water is water. As long as the water isn't at more pressure than the seal is rated for it will hold

  8. #8
    Grand Master MartynJC (UK)'s Avatar
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    Yes

    .
    .

  9. #9
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    But what do you mean by 'humidity resistant'? What would be the symptoms of failed humidity resistance?
    I recall reading something years ago where some guy said that he went to live in Hong Kong or somewhere similarly hot and humid and found his 'posh' watch rusted on his wrist!

  10. #10
    People get confused with resistance to liquid water and water vapour. Watches are not resistant to water vapour as gaskets are permeable to it.

    Molecules of water vapour are very small and of a shape that can penetrate rubber/polyurethane gaskets. Given enough time and it can be a long time, humidity will always equalise between the outside and inside of the watch due to Vapour Pressure. If you live in a high humidity climate eventually you will have high humidity in your watch no matter how dry an environment it was constructed in, and vice versa also.

    Molecules in liquid water have a very strong bond between each other and this means they cannot pass through the gaskets. This strong attraction between water molecules can be seen as drops of water will pull themselves into a spherical shape if possible.

    Sudden changes of temperature to the outside of the crystal can cause condensation but it is only fleeting and will quickly go away. So unless you are specifically looking for it you will not notice it. The higher the humidity in the watch the more condensation there will be.

    Sinn produce watches that have an anti humidity capsule built in but eventually this capsule will have to be replaced as water vapour will still be permeating into the watch.


    "The case features a copper sulphate capsule which reacts with moisture to diffuse and absorb humidity in the watch. This capsule may be viewed through a porthole in the left lug, and over time will turn a deep blue as humidity is absorbed. This technology not only provides a more stable environment for the movement, but also helps to prevent fogging of the crystal when going from hot to cold environments or from humid to non-humid conditions (such air conditioned buildings"



    Polymers are much more permeable to water vapour than other gases including Helium (many times more) and does not require high pressure. Higher temperatures will increase permeation rates though and it obviously is highly dependant on the Vapour Pressure on either side of the barrier.

    If you are interested check out some of the papers for some indication of permeation rates.

    https://www.google.co.uk/search?q=pe...7WLIvT7AaRh4BA



    The PDF by Sturm (third one down) Gives the rates at Table 1.



    Here is a much simpler table just giving the permeability coefficient of various polymers to just Oxygen and Water Vapour.


    http://www.faybutler.com/pdf_files/H...AffectGas3.pdf


    The Polymers are vastly more permeable to Water Vapour than Oxygen, up to thousands of times more.

    There is a reason why Sinn and Tag mention the possibility of fogging up of the crystal and why Sinn install this anti Water Vapour system in some of their watches. That reason is that permeation of Water Vapour cannot be prevented on normal watches and Water Vapour is subject to condensation on rapid change of temperature.




    Mitch
    Last edited by Mitch; 13th September 2018 at 12:25.

  11. #11
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    The nside of the watch is not in vacuum. There is air inside. If at the time of sealing the watch it was done in an environment with some humidity, that watch will fog up in the cold.

    My casio aviator 200m fogged up one cold day.

  12. #12
    Master bedlam's Avatar
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    Quote Originally Posted by Mitch View Post
    People get confused with resistance to liquid water and water vapour. Watches are not resistant to water vapour as gaskets are permeable to it.

    Molecules of water vapour are very small and of a shape that can penetrate rubber/polyurethane gaskets.
    Um, no. The physical size of a water molecule will not vary to the degree it would make any difference between being in solution vs being in a gas.

  13. #13
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    Interesting question, never really considered this before. I would have thought if a watch is water resistant it would be resistant to humidity on some level


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  14. #14
    Quote Originally Posted by bedlam View Post
    Um, no. The physical size of a water molecule will not vary to the degree it would make any difference between being in solution vs being in a gas.

    Are you just speculating, because you are wrong? Water molecules in solution permeate very differently than when in their gaseous state.




    "Water molecules are tiny, electrically neutral and V-shaped with molecular formula H2O a and molecular diameter about 2.75 Ň. Water is much smaller than almost all other molecules. For example, it has a smaller volume, and is much lighter, than the four other common atmospheric molecules, oxygen (O2), nitrogen (N2), argon (Ar) and carbon dioxide (CO2); the density of water vapor being just 62% the density of dry air."



    "In liquid water, the mean O-H length is about 0.097 nm, the mean H-O-H angle is about 106į and the mean negative charge on the oxygen atom is about 70% of that of an electron with each hydrogen atom positively charged sharing the neutralising charge. Individual water molecules will have different values for these parameters dependent on their energy and surroundings."



    "The opposite charges on the oxygen and hydrogen atoms causes different water molecules to attract each other. This attraction is particularly strong when the O-H bond from one water molecule points directly at a nearby oxygen atom in another water molecule, that is, when the three atoms O-H O are in a straight line. This is called 'hydrogen bonding' as the hydrogen atoms appear to hold on to both O atoms. This attraction between neighbouring water molecules, together with the high-density of molecules due to their small size, produces a great cohesive effect within liquid water that is responsible for water's liquid nature at ambient temperatures."



    Mitch

  15. #15
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    Quote Originally Posted by Mitch View Post
    Are you just speculating, because you are wrong? Water molecules in solution permeate very differently than when in their gaseous state.




    "Water molecules are tiny, electrically neutral and V-shaped with molecular formula H2O a and molecular diameter about 2.75 Ň. Water is much smaller than almost all other molecules. For example, it has a smaller volume, and is much lighter, than the four other common atmospheric molecules, oxygen (O2), nitrogen (N2), argon (Ar) and carbon dioxide (CO2); the density of water vapor being just 62% the density of dry air."



    "In liquid water, the mean O-H length is about 0.097 nm, the mean H-O-H angle is about 106į and the mean negative charge on the oxygen atom is about 70% of that of an electron with each hydrogen atom positively charged sharing the neutralising charge. Individual water molecules will have different values for these parameters dependent on their energy and surroundings."



    "The opposite charges on the oxygen and hydrogen atoms causes different water molecules to attract each other. This attraction is particularly strong when the O-H bond from one water molecule points directly at a nearby oxygen atom in another water molecule, that is, when the three atoms O-H O are in a straight line. This is called 'hydrogen bonding' as the hydrogen atoms appear to hold on to both O atoms. This attraction between neighbouring water molecules, together with the high-density of molecules due to their small size, produces a great cohesive effect within liquid water that is responsible for water's liquid nature at ambient temperatures."



    Mitch
    Do you actually Ďknowí this stuff or have you been busy on Google?

    Speaking with the (rarely used) chemistry graduate head on, youíre not wrong about water, but whether your hypothesis translates into a real- life issue regarding water vapour entering a watch is another matter.

    The permeability of a rubber gasket isn't something that I would intuitively consider; in theory youíre correct but in practice a watch that can withstand a few bar air pressure wonít have a problem in normal use. Iíd be amazed if thete are any instances where a watch thatís watertight and airtight has suffered owing to permeation of gaseous water molecules through the rubber seals.

    Maybe my good habit of wiping all seals with silicone grease helps combat permeation, it creates another small layer for those pesky water molecules to fight their way through!

    Paul

  16. #16
    Quote Originally Posted by walkerwek1958 View Post
    Do you actually Ďknowí this stuff or have you been busy on Google?

    Speaking with the (rarely used) chemistry graduate head on, youíre not wrong about water, but whether your hypothesis translates into a real- life issue regarding water vapour entering a watch is another matter.

    The permeability of a rubber gasket isn't something that I would intuitively consider; in theory youíre correct but in practice a watch that can withstand a few bar air pressure wonít have a problem in normal use. Iíd be amazed if thete are any instances where a watch thatís watertight and airtight has suffered owing to permeation of gaseous water molecules through the rubber seals.

    Maybe my good habit of wiping all seals with silicone grease helps combat permeation, it creates another small layer for those pesky water molecules to fight their way through!

    Paul

    I am sorry Paul but you are wrong. Due to the small size and particularly the shape of the molecule, Water Vapour permeates much easier through polymer/rubber gaskets than other gases.

    Using a watch based example, you know that Helium permeates through watch gaskets and the higher the vapour pressure either side of the gasket the faster this occurs. That is why some watches have an Helium escape valve. Water Vapour does the same, except much faster.

    Dependant on the composition of the polymer gasket, Water Vapour can permeate at a hundred times or more the rate of Helium.

    Vitron gaskets appear to be the best bet for Water Vapour permeation reducing the rate to about three or four time the rate of Helium.



    Mitch

  17. #17
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    I remember reading about Vostok and how the water pressure is used to create the seal in their gaskets.

  18. #18
    Master alfat33's Avatar
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    Quote Originally Posted by walkerwek1958 View Post
    ...wonít have a problem in normal use.
    Paul, isnít this the critical point? General wear, swimming, diving etc., no problem. 6 months in a humid, tropical atmosphere or steamy working environment, maybe not good.

    Also not all watertight watches rely exclusively on rubber type seals, e.g. crystals might be friction fit. Would that make a difference?

  19. #19
    Master bedlam's Avatar
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    Quote Originally Posted by Mitch View Post
    Are you just speculating, because you are wrong? Water molecules in solution permeate very differently than when in their gaseous state.

    "Water molecules are tiny, electrically neutral and V-shaped with molecular formula H2O a and molecular diameter about 2.75 Ň. Water is much smaller than almost all other molecules. For example, it has a smaller volume, and is much lighter, than the four other common atmospheric molecules, oxygen (O2), nitrogen (N2), argon (Ar) and carbon dioxide (CO2); the density of water vapor being just 62% the density of dry air."

    "In liquid water, the mean O-H length is about 0.097 nm, the mean H-O-H angle is about 106į and the mean negative charge on the oxygen atom is about 70% of that of an electron with each hydrogen atom positively charged sharing the neutralising charge. Individual water molecules will have different values for these parameters dependent on their energy and surroundings."

    "The opposite charges on the oxygen and hydrogen atoms causes different water molecules to attract each other. This attraction is particularly strong when the O-H bond from one water molecule points directly at a nearby oxygen atom in another water molecule, that is, when the three atoms O-H O are in a straight line. This is called 'hydrogen bonding' as the hydrogen atoms appear to hold on to both O atoms. This attraction between neighbouring water molecules, together with the high-density of molecules due to their small size, produces a great cohesive effect within liquid water that is responsible for water's liquid nature at ambient temperatures."

    Mitch
    Its a real-world question. Showers, hot-tubs and the like. How exactly is the average watch going to be exposed to temperatures where the hydrogen bonding of a water molecule is going to be affected? Seriously.

  20. #20
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    The hydrogen bonding aspects of water didn`t immediately spring to mind when I addressed this question. .........I`m struggling to see how relevant this is!

    Mitch clearly knows more about the permeability of polymers wrt water vapour than most of us, but I still question whether there's a likely scenario where this could be an issue in the context of a watch worn in normal circumstances. I can`t think of one.

    Suffice to say I`ve had lots of watches that pass a 3bar pressure test, they've been used in all conditions and I`ve never once had a problem with misting up.

    Never mind the finer points of theory, is the fact that a polymer gasket does posses a finite permeation rate wrt water vapour a problem?

    Answers on a postcard!

    Still don`t know why the OP asked the question.
    Last edited by walkerwek1958; 13th September 2018 at 15:23.

  21. #21
    Master bedlam's Avatar
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    Quote Originally Posted by Mitch View Post
    I am sorry Paul but you are wrong. Due to the small size and particularly the shape of the molecule, Water Vapour permeates much easier through polymer/rubber gaskets than other gases.

    Using a watch based example, you know that Helium permeates through watch gaskets and the higher the vapour pressure either side of the gasket the faster this occurs. That is why some watches have an Helium escape valve. Water Vapour does the same, except much faster.

    Dependant on the composition of the polymer gasket, Water Vapour can permeate at a hundred times or more the rate of Helium.

    Vitron gaskets appear to be the best bet for Water Vapour permeation reducing the rate to about three or four time the rate of Helium.
    Helium (31 picometers) is far smaller than either oxygen (48 pico) or hydrogen (53 pico), let alone a combination of them in an H2O molecule. Which is why they have Helium excape valves, but don't need water vapour escape valves.
    Last edited by bedlam; 13th September 2018 at 15:27.

  22. #22
    Quote Originally Posted by Mitch View Post
    I am sorry Paul but you are wrong. Due to the small size and particularly the shape of the molecule, Water Vapour permeates much easier through polymer/rubber gaskets than other gases.

    Using a watch based example, you know that Helium permeates through watch gaskets and the higher the vapour pressure either side of the gasket the faster this occurs. That is why some watches have an Helium escape valve. Water Vapour does the same, except much faster.

    Dependant on the composition of the polymer gasket, Water Vapour can permeate at a hundred times or more the rate of Helium.

    Vitron gaskets appear to be the best bet for Water Vapour permeation reducing the rate to about three or four time the rate of Helium.



    Mitch
    Do we need to understand that the water molecule is smaller in vapor state ? And teh watch can be watertight, but not airtight ? Strange ...

  23. #23
    Grand Master MartynJC (UK)'s Avatar
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    So should every watch have a Ďwater-vapourí escape valve fitted? This is getting very silly.

  24. #24
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    Quote Originally Posted by danmiddle2 View Post
    I can't think of any reason why not. Essentially humidity is also water and under way less pressure. I'd have to say yes, but not an authoritative opinion.
    Id agree too

  25. #25
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    Such a technical thread but interesting to read! I would suggest that the answer is 'yes'.

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  26. #26
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    1) Water molecules don't change size in their different states. The phase changes are caused by hydrogen-oxygen bonds forming and breaking between neighbouring molecules. If the h-o-h bonds of the molecule changed, it wouldn't be water any more

    2) helium escape valves, as every fule no, are fitted to watches intended for the very unique environment of saturation diving, during which the diver ( and his Deep Sea) live in an environment held at the ambient water pressure, thus allowing them to leave and re-enter the environment with out incurring a a decompression penalty. Because these dives are too deep to breathe air, the gas mix they breathe in the environment (and on the dive) is helium rich. At a working depth of say 200m, the pressure is 20bar, and this high pressure forces the He molecules either through (permeating) or past (due to seal compression) the seals. No problem, until the diver begins deco and the pressure in the environment is reduced, the gas in the watch can't escape quickly enough and thus the gas in the watch expands and the watch explodes. The escape valve activates on pressure differential and lets excess gas escape.

    This has nothing to do with water vapour getting inside watches, however.

    3) Helium, obvs, is smaller than a water molecule. Helium is monatomic, and it's an element. Water has 2 hydrogen molecules, both of which are bigger than helium molecules, and an oxygen molecule, the negative charge on which gives water some of it's odd properties, as it forms a loose bond with the slightly +ve charge on a neighbouring molecule. Water is a very small molecule, but it's still a molecule

    4) As Mitch says, though, water vapour does have a very high permeability coefficient across the stuff seals are usually made of. This means it can migrate through the O ring, and since molecules will always seek to equalise across a semi permeable membrane (the seal) if their is more water vapour on one side of the seal than the other it will seek to equalise across the diffusion gradient - ie from more stuff to less stuff. There's an enormously complicated way of calculating this, based on the permeation coefficient and the cross section size of the seal material. I haven't done the calculation but my rough estimate is it takes years and years and years, and then only if the concentration of water molecules is in the air is higher outside than inside the watch. As mentioned by someone above, their will be some water vapour in the watch unless it was sealed in a vacuum, but not much (unless the watch maker was sat in a sauna)

    5) However, water vapour is not more transmissive than the small molecules of the gases mentioned. Easy mistake to make, since the permeation coefficient is usually measured in an non SI unit called a barrer, which measures the amount of time it takes for a measured mass of gas to move across the membrane - bigger number means more seconds.

    6) Anyway, the barrer measurements are non SI, which means they are measured in lots of different ways so don't mean much

    7) Also, we don't care, since we want to know how much water vapour will actually pass across the membrane (transmission rate), which permeability coefficients don't help with

    8) Also, transmission rate doesn't really help since that doesn't take into account pressure or temperature, which clearly have the biggest impact

    9) However, I've done lots of empirical tests by sitting in Saunas, Jacuzzis and steam rooms, note, with diving watches only, and I've never got condensation in any of them, ever. So no, water vapour doesn't get into watches, at least those are dive rated

    10) Yes, I am a chemist

  27. #27
    Master danmiddle2's Avatar
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    9) However, I've done lots of empirical tests by sitting in Saunas, Jacuzzis and steam rooms, note, with diving watches only, and I've never got condensation in any of them, ever. So no, water vapour doesn't get into watches, at least those are dive rated
    me too... no issues either!

  28. #28
    Grand Master AlphaOmega's Avatar
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    What an excellent thread.

  29. #29
    Quote Originally Posted by berin View Post
    1) Water molecules don't change size in their different states. The phase changes are caused by hydrogen-oxygen bonds forming and breaking between neighbouring molecules. If the h-o-h bonds of the molecule changed, it wouldn't be water any more

    2) helium escape valves, as every fule no, are fitted to watches intended for the very unique environment of saturation diving, during which the diver ( and his Deep Sea) live in an environment held at the ambient water pressure, thus allowing them to leave and re-enter the environment with out incurring a a decompression penalty. Because these dives are too deep to breathe air, the gas mix they breathe in the environment (and on the dive) is helium rich. At a working depth of say 200m, the pressure is 20bar, and this high pressure forces the He molecules either through (permeating) or past (due to seal compression) the seals. No problem, until the diver begins deco and the pressure in the environment is reduced, the gas in the watch can't escape quickly enough and thus the gas in the watch expands and the watch explodes. The escape valve activates on pressure differential and lets excess gas escape.

    This has nothing to do with water vapour getting inside watches, however.

    3) Helium, obvs, is smaller than a water molecule. Helium is monatomic, and it's an element. Water has 2 hydrogen molecules, both of which are bigger than helium molecules, and an oxygen molecule, the negative charge on which gives water some of it's odd properties, as it forms a loose bond with the slightly +ve charge on a neighbouring molecule. Water is a very small molecule, but it's still a molecule

    4) As Mitch says, though, water vapour does have a very high permeability coefficient across the stuff seals are usually made of. This means it can migrate through the O ring, and since molecules will always seek to equalise across a semi permeable membrane (the seal) if their is more water vapour on one side of the seal than the other it will seek to equalise across the diffusion gradient - ie from more stuff to less stuff. There's an enormously complicated way of calculating this, based on the permeation coefficient and the cross section size of the seal material. I haven't done the calculation but my rough estimate is it takes years and years and years, and then only if the concentration of water molecules is in the air is higher outside than inside the watch. As mentioned by someone above, their will be some water vapour in the watch unless it was sealed in a vacuum, but not much (unless the watch maker was sat in a sauna)

    5) However, water vapour is not more transmissive than the small molecules of the gases mentioned. Easy mistake to make, since the permeation coefficient is usually measured in an non SI unit called a barrer, which measures the amount of time it takes for a measured mass of gas to move across the membrane - bigger number means more seconds.

    6) Anyway, the barrer measurements are non SI, which means they are measured in lots of different ways so don't mean much

    7) Also, we don't care, since we want to know how much water vapour will actually pass across the membrane (transmission rate), which permeability coefficients don't help with

    8) Also, transmission rate doesn't really help since that doesn't take into account pressure or temperature, which clearly have the biggest impact

    9) However, I've done lots of empirical tests by sitting in Saunas, Jacuzzis and steam rooms, note, with diving watches only, and I've never got condensation in any of them, ever. So no, water vapour doesn't get into watches, at least those are dive rated

    10) Yes, I am a chemist
    Couple of thought on this: -

    The permeation rate is proportional to the permeation coefficient (as given in tables in references) so a higher coefficient will surely mean more water (vapour) ingress. May still be negligible of course.

    In practice, don't think temperature will have much effect as watch temperature will be very similar to body temperature.

  30. #30
    Quote Originally Posted by bedlam View Post
    Helium (31 picometers) is far smaller than either oxygen (48 pico) or hydrogen (53 pico), let alone a combination of them in an H2O molecule. Which is why they have Helium excape valves, but don't need water vapour escape valves.
    Permeability depends on the shape of the molecule as well as the size. Oxygen and Hydrogen exist as molecules in our atmosphere not as single atoms.


    Here are actual permeable rates as confirmed by various experimental sources. Water Vapour's permeability exceeds the other gases by an enormous amount. The actual composition of the polymer affects the rate different gases will permeate, again the shape of the molecule influences this.


    See Table 1 of this paper.



    https://agupubs.onlinelibrary.wiley....9/2003JD004073


    Many things influence the actual permeability rate, thickness of gasket being an obvious one. Vapour Pressure is a major one the greater the difference in vapour pressure across the barrier the greater the rate of permeation.

    As an example if you have a car tyre and leave it, it will lose pressure as the air permeates out and eventually go flat if left long enough.

    If the tyre was filled with pure oxygen it would exhibit the same behaviour. However, Nitrogen and CO2 etc would be permeating into the tyre whilst this was going on, actual gas pressure in the tyre would not affect this. Eventually the tyre would be flat but with an equal composition of air as outside the tyre.



    Mitch
    Last edited by Mitch; 13th September 2018 at 20:52.

  31. #31
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    Quote Originally Posted by Tinker View Post
    Is a watch that's water resistant also humidity resistant?
    Did you just want to know whether you could take your watch in the steam room in holiday?!!!

    2 -How many chemists and physicists have answered this thread?

    3 - this is probably the most intellectual watch thread I've ever read.

  32. #32
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    Quote Originally Posted by Mitch View Post
    Permeability depends on the shape of the molecule as well as the size. Oxygen and Hydrogen exist as molecules in our atmosphere not as single atoms.


    Here are actual permeable rates as confirmed by various experimental sources. Water Vapour's permeability exceeds the other gases by an enormous amount. The actual composition of the polymer affects the rate different gases will permeate, again the shape of the molecule influences this.


    See Table 1 of this paper.



    https://agupubs.onlinelibrary.wiley....9/2003JD004073


    Many things influence the actual permeability rate, thickness of gasket being an obvious one. Vapour Pressure is a major one the greater the difference in vapour pressure across the barrier the greater the rate of permeation.

    As an example if you have a car tyre and leave it, it will lose pressure as the air permeates out and eventually go flat if left long enough.

    If the tyre was filled with pure oxygen it would exhibit the same behaviour. However, Nitrogen and CO2 etc would be permeating into the tyre whilst this was going on, actual gas pressure in the tyre would not affect this. Eventually the tyre would be flat but with an equal composition of air as outside the tyre.



    Mitch


    Err, no. I read the paper you quoted. It's very practical, and in fact its stuff that I used to to have to do, as I collected remote samples in the field and needed to know about how the contents may change.

    It gives the same coefficients - and they say very clearly that a very very tiny atom of helium will permeate - remember this mean dissolving into a substrate, the polymer, and then emerging out the other side, much more quickly than a big molecule.

    It's not rocket science. Small stuff gets through small spaces better then big stuff.

    If you're going to say, got you, I'm professor of permeation dynamics at Imperial, then I'll bow to your superior wisdom, but mostly it looks like you've just trawled some stuff on the internet.

    I even forgot what your original point was, except that if it was true possibly everybody's watches would be full of water.

  33. #33
    Quote Originally Posted by berin View Post
    Err, no. I read the paper you quoted. It's very practical, and in fact its stuff that I used to to have to do, as I collected remote samples in the field and needed to know about how the contents may change.

    It gives the same coefficients - and they say very clearly that a very very tiny atom of helium will permeate - remember this mean dissolving into a substrate, the polymer, and then emerging out the other side, much more quickly than a big molecule.

    It's not rocket science. Small stuff gets through small spaces better then big stuff.

    If you're going to say, got you, I'm professor of permeation dynamics at Imperial, then I'll bow to your superior wisdom, but mostly it looks like you've just trawled some stuff on the internet.

    I even forgot what your original point was, except that if it was true possibly everybody's watches would be full of water.
    What are you saying exactly?

    That all scientific experiments showing that Water Vapour has a much higher permeability coefficient than Helium, across a polymer barrier, are wrong? Have you conducted your own experiments, have you got the true figures you can let us have?

    As well as size, the shape of the molecule affects the permeability rate.

    Sinn make watches with a capsule that absorbs water vapour. They start life filled with a gas with no water vapour present and with more resistant polymer gaskets than the usual watch (probably Viton I reckon) but over time that capsule of copper sulphate will turn blue as it absorbs the water vapour permeating into the watch and will need replacing. Nothing wrong with the watches but they cannot prevent water vapour getting in.


    https://www.sinn.de/en/Ar-Dehumidifying_Technology.htm



    Mitch

  34. #34
    Quote Originally Posted by berin View Post

    I even forgot what your original point was, except that if it was true possibly everybody's watches would be full of water.
    You seem to not have a strong grasp of the subject. Permeation of water vapour will only happen if the vapour pressure is higher on the outside of the watch and will stop when it equalises, it does not keep going to fill the watch with water. If the watch was made in a high humidity environment and is moved to a lower humidity area, water vapour will permeate out of the watch.



    Mitch

  35. #35
    Master murkeywaters's Avatar
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    So just to chuck a spanner in the works, how does my Sinn EZM2 cope with vapour as its filled with oil and classed as waterproof - not water resistant?

    We need a picture of a watch in this thread before us at the back keel over asleep!


  36. #36
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    Quote Originally Posted by walkerwek1958 View Post

    Still don`t know why the OP asked the question.

    Thatís because you already know (or in your opinion, know) the answer! Itís perfectly acceptable for someone to ask a question if they would like to learn something.

  37. #37
    Quote Originally Posted by Bobbyf View Post
    Thatís because you already know (or in your opinion, know) the answer! Itís perfectly acceptable for someone to ask a question if they would like to learn something.
    Don't think he did.

  38. #38
    Quote Originally Posted by murkeywaters View Post
    So just to chuck a spanner in the works, how does my Sinn EZM2 cope with vapour as its filled with oil and classed as waterproof - not water resistant?

    We need a picture of a watch in this thread before us at the back keel over asleep!

    ]

    No water vapour can get in there and the WR must be incredible.




    Mitch

  39. #39
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    Quote Originally Posted by MrGrumpy View Post
    But what do you mean by 'humidity resistant'? What would be the symptoms of failed humidity resistance?
    I recall reading something years ago where some guy said that he went to live in Hong Kong or somewhere similarly hot and humid and found his 'posh' watch rusted on his wrist!
    It doesn't have to be hot to be humid. England may not have the heat but its Very humid, right up there with louisiana or Singapore.

    https://www.currentresults.com/Weath...y-november.php

  40. #40
    Master murkeywaters's Avatar
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    Quote Originally Posted by Mitch View Post
    No water vapour can get in there and the WR must be incredible.
    Thatís nice know! It is regarded this watch will go beyond 12000ft which for a 11mm thick watch is very impressive..

  41. #41
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    Quote Originally Posted by Bobbyf View Post
    Thatís because you already know (or in your opinion, know) the answer! Itís perfectly acceptable for someone to ask a question if they would like to learn something.
    I would've expected some response from the OP. In all my years of involvement with watches it isn`t a question that would've entered my head; that's why I asked the question.

    Have you any constructive input to add?

  42. #42
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    Quote Originally Posted by walkerwek1958 View Post
    I would've expected some response from the OP. In all my years of involvement with watches it isn`t a question that would've entered my head; that's why I asked the question.

    Have you any constructive input to add?
    I can only provide real world experience in that I have never had a problem with any watch I've used in hot and humid conditions. The only watches that have ever shown condensation is a g shock which mists over for a few minutes when going out into the cold from a warm environment.
    Iím not a watchmaker, physicist or chemist but I can spot a condescending tone a mile off.

  43. #43
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    Living in a country where humidity in the summer regularly goes over 90% I have never had a problem with humidity in any of my watches - however my assistant brought in her brother's watch this week that was completely fogged - beyond my abilities to fix and not economic to repair.
    On a similar theme lens fungus is an issue for photographers here it is best not to keep lenses in cold A/C and work with them outside- obviously they are not constructed to watch WR standards.

    Interesting thread to read - thanks all.

  44. #44
    Quote Originally Posted by MarkO View Post
    Living in a country where humidity in the summer regularly goes over 90% I have never had a problem with humidity in any of my watches - however my assistant brought in her brother's watch this week that was completely fogged - beyond my abilities to fix and not economic to repair.
    On a similar theme lens fungus is an issue for photographers here it is best not to keep lenses in cold A/C and work with them outside- obviously they are not constructed to watch WR standards.

    Interesting thread to read - thanks all.
    You could also have 90% humidity inside the watch and wouldnít necessarily see anything.

  45. #45
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    Quote Originally Posted by Mitch View Post
    What are you saying exactly?

    That all scientific experiments showing that Water Vapour has a much higher permeability coefficient than Helium, across a polymer barrier, are wrong? Have you conducted your own experiments, have you got the true figures you can let us have?
    The experiment has been running for decades. People living their whole lives in humid climates don't report their dive watches having problems with humidity ingress. People in saturation chambers find helium in similar dive watches within days.

    Theory aside, the data is clear. The OP can expose his watch to high humidity without intrusion into the watch in any context that is safe for him to be in. The same would not be true for helium. The WR that makes the watch dive capable means it is also resistant to water vapour.

  46. #46
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    This issue reminds me of the comparison between 904 and 316 steel for dive watches. Advocates for 904 say it is more corrosion resistant, but its not more corrosion resistant in the conditions that a human could survive. Claims about things do need to pay attention to the context in which those things actually happen.

  47. #47
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    Quote Originally Posted by bedlam View Post
    People living their whole lives in humid climates don't report their dive watches having problems with humidity ingress.

    England has a humid climate. Its a "Temperate Maritime" climate.

    It doesn't have to be a hot climate to be a humid one.

    High temperature and High relative humidity can overheat a body because the water moisture in the air prevents the sweat from evaporating off your skin. Your pores basically clog up and you overheat. That's when you really feel humidity and perhaps thats why we associate humidity with heat, but heat is not necessary.

    So if you have a watch in England. Its in a humid climate.

    https://www.quora.com/In-the-UK-why-...all-year-round

  48. #48
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    Quote Originally Posted by MikeP View Post
    It doesn't have to be hot to be humid. England may not have the heat but its Very humid, right up there with louisiana or Singapore.

    https://www.currentresults.com/Weath...y-november.php
    True...however, my vague recollection of school physics tells me that the hotter air is, the higher its capacity to hold water (or maybe my brain has failed again). In that case, even though the % humidity of Scotland and Hong Kong might be the same, there would be a lot more moisture in the air in Hong Kong???

  49. #49
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    Accepting that permeation of water vapour (water molecules in the gaseous state) through a polymer seal can occur, treating the surface of the polymer with a substance such as silicone grease may influence the permeation coefficient. Whether this serves to reduce the overall permeation coefficient or not cannot be predicted without knowing the permeation coefficient for silicone grease. A value for silicone rubber is quoted, itís orders of magnitude higher than the value for viton rubber, but does that imply that the permeation coefficient for water vapour/silicone grease will be correspondingly high? ........I donít know.

    Treating seals with silicone grease is standard practice when fitting to a watch. I donít mean smearing it on liberally, itís wiped on and wiped off thus leaving a trace as a monolayer on the surface. Its primary purpose is to lubricate the seal, but it also serves to increase the hydrophobic nature of the seal (and mating faces of the watch) thus improving the likelihood that water ingress will be avoided when the mating surfaces are less than perfect; this condition exists when crevice corrosion has ocurred on old stainless steel watches to cause pitting, greasing the seal wonít give much improvement in WR but an increase from zero to splashproof (literally) is huge advantage!

    What I donít know is whether silicone grease permeates into the rubber, I suspect it may be absorbed to some extent. If this happens the permeation of gases through the rubber us likely to be influenced and (hopefully) be reduced. What troubles me on this point is why the folks who addressed the problem of flawed sampling/ results ( quoted in the paper) didnít try this as a simple expedient......perhaps it didnít work?

    All this conjecture is interesting to a greater or lesser extent, but I question how relevent it all is to the wristwatch scenario! Iíll continue to treat seals with silicone grease, Iíll pressure test watches in air, if they pass the test they wonít suffer from damp/condensation/water ingress problems,of that Iím confident. Whether the humidity inside the watch is changing or not wonít worry me, if the big manufacturers arenít worried neither am I.

    At least itís given my ageing brain cells some excercise!

  50. #50
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    Molycote silicone grease is the best for seals in a HeO2 environment I find.

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