Jump to content
TJGladeRaider

Waterproof Watch Testers

Recommended Posts

It was suggested that I repost this for the knowledge base so I have revised it a bit.

Before we start, this is a bit complicated and people may choose to weigh in with different opinions and explanations. If you choose to invest the time and effort necessary to follow this, it is not wasted. I am a Dive Master with something in excess of 3000 HRs underwater, and my second academic pursuit was Mechanical Engineering. I understand Boyles Law perfectly well, PV=NRT is very basic to me, and I am perfectly well qualified to teach this.

I say that because there were some differences of opinion last time this was discussed.

Here we go.

Understand that there is pressurized air inside your watch. If you are standing at sea level, it should be at about 14.7 psi - but we will say 15 to keep the math easy. It doesn't seem pressurized to us because everything is at 15psi - standard atmospheric pressure. If you took that watch into outer space while stuck inside a skin tight balloon, and popped the stem (or otherwise compromised the structural integrity of the case), air would come rushing out to expand the balloon.

If you can understand that -- everything else that follows will be simple.

Personally, I have no use for a watch that isn't genuinely water resistant. I test all of mine:

post-223-1160237495_thumb.jpg

post-223-1160233610_thumb.jpg

post-223-1160233633_thumb.jpg

post-223-1160233655_thumb.jpg

post-223-1160237556_thumb.jpg

post-223-1160237605_thumb.jpg

I think I can say with some confidance that the prevailing belief that reps are not waterproof is a holdover from the old days when they came with cardboard spacers and Timex movements.

post-223-1160237172_thumb.jpg

post-223-1160237190_thumb.jpg

To test a watch, you put the watch in the device - feel free to use paperclips, or whatever you need to help suspend the watch if you prefer to leave the bracelet on.

To start with, there is no reason to go overboard, so pump the pressure up to TWO of atmospheres.

Now, if you are really following along, you would know that you have added two atmoshperes worth of pressure (30 PSI) to the cylinder outside the watch for a total pressure outside the watch of 45 PSI (since everything started at 15 psi).

Now, LET THE WATCH HANG THERE A FEW MINUTES TO EQUALIZE IF IT IS GOING TO (Hopefully, it won't) If the watch equalized while up in the air, that means it is not airtight.

In other words, and this is the part to understand, there was a small volume of air at normal atmospheric pressure inside the watch going into the chamber (say for example purposes on cubic inch of air at 15 PSI)

If you add two atmospheres of pressure, you have tripled the pressure from 1 to 3, but if the watch is airtight, NOTHING happens inside.

That's why men can spend forever in a submarine at significant depths with no decompression issues, but if the watch was an airtight balloon, you would watch it shrink to a third it's size which is exactly what you do see if you take a balloon down underwater about 66 feet.

If the watch is not airtight, the pressure will equalize inside the watch and that means that the amount of air inside the watch will triple - three times the pressure means that three times the volume of air fits into the same space, so what we need to know is, do we have one cubic inch of air inside that one cubic inch case at 15 PSI, or three cubic inches of air at 45PSI.

Lower the watch into the water.

SLOWLY release the pressure -- did I say SLOWLY!!!!!! DO NOT - NOT - NOT dump the pressure.

SLOWLY releasing the pressure releases the pressure on the enitre system - the air, the water, and the watch. As the pressure releases, NOTHING happens inside the airtight watch - like the men in the submarine, they don't know the difference.

On the other hand, if our little experiment packed three cubic inches of air into a one cubic inch space, releasing the pressure makes that air want to come right back out.

At this point, let me focus you on something - think about the inside of the watch case - including the space between the dial and the crystal. Even though the watch looks like it is pretty much filled up with a movement, there is still a LOT of airspace in there. If you take that volume and add twice that volume to it - twice the volume of airspace inside that watch is a LOT of air. When you release it, it isn't going to be a few bubbles.

More on that later.

If air come's pouring out of that watch as you are SLOWLY releasing the pressure -- DO NOT STOP. DO NOT STOP, but even more importantly, DO NOT - NOT - NOT let the pressure go to zero. NO, NO, NO, NO, NO! Pull that watch up out of the water while the pressure is slowly dropping and before it hits zero.

IT MUST NOT GO TO ZERO while a leaky watch is under water becasue once the positive air pressure bleeds out, water can get in. No water can get in that leaky watch while the air pressure inside is bleeding out.

Now, back to my point about volume.

If you test your watches with bezels before reading this, you will report back that they all leak. Not so.

When you pressurized the system, you did that by pumping in air. You stuffed three times the air into that system that was originally there so you pumped three times the air into the space beneath the bezel, where the lug holes are, etc that would be there without all that pressure.

That little airbubble trapped under the bezel, or inside the lug hole, or wherever, is going to expand to three times its size as the pressure released and as it does, it won't fit there anymore. In other words, a few little bubbles are perfectly normal.

Remember, when you pump in six atmospheres of pressure, you are compressing all the air inside that cylinder, forcing every space to hold seven times as much air as it held to start with. That is a HUGE differential.

Watch the springbars and you will see bubbles coming from them, as well as from under the bezel, lug holes, from the underside of lugs . . . anywhere a tiny bubble could cling. When that bubble gets seven times as large, it will float up.

Believe me, when seven times the vollume of air normally inside a watch case comes rushing out, nobody will have to tell you it leaked.

If it passes just fine at two atm, repeat the process at five or six.

You will find that any of the better quality reps does just fine.

Good luck,

Bill

  • Like 4

Share this post


Link to post
Share on other sites
bkdc    0

Great post. OMG that's an obscene collection. How many Rollie subs does one really need????

Share this post


Link to post
Share on other sites
Tropic    0

Great Article,

Explaining in detail what happens during pressure testing.....

Now could you Explain the Procedure in simple step by step for the Dummy's under us? :bangin:

Without Academic theory's? :huh:

Ok Serious now, Noobs, Newbies, Non graduates, DON'T TRY THIS AT HOME! :cc_confused:

Unless You really did understand what the Intellegent Gentleman Said! ;)

I try Again, You are NOT seriously suggesting that People would trust their Asian REPLICA of A Divers watch,

After they Pressure tested It, and depending nothing less then their life (Who Cares About A Wet Replica when Youre Dead?) On It, While Scuba Diving!?

I say this in Jest, and warning to the reader, not the Gentleman who posted this Intersting topic, I take him to Smart to sugest otherwise (As A Life long Free Diver myself) ;):fish:

Oh, And I know they have Dive Computers these days, Still A certified Divers Watch is A Security Backup!

Maybe You Could Pressure test Some watches from Members of this comunity? If theywould Like to take it Swimming or Snorkeling?

Regards,

Kees

Share this post


Link to post
Share on other sites

Very informative post... Mod this should be in the KB indeed. Now where can one purchase testing machines...

TJ are those Bulova vintage ones that just work with airvaccuum and a soapbubble solution on the leak areas usable...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...A%3AIT&rd=1

or is that for rain and sneezeproofness :p

Share this post


Link to post
Share on other sites
Great Article,

Explaining in detail what happens during pressure testing.....

Maybe You Could Pressure test Some watches from Members of this comunity? If theywould Like to take it Swimming or Snorkeling?

Regards,

Kees

As I have said many times, I PERSONALLY have no problem with wearing a rep SCUBA diving - but I do NOT recommend it.

The reason is that SCUBA is a dynamic of time and pressure where everything is affected and once you become thoroughly comfortable with the interaction, and have the experience to know how it all works for you, a guy LIKE ME with 3000+ hours under water has no need for a watch under normal circumstances.

I say LIKE ME not based so much on my experience, but more on personal limitations. At my age, I don't conserve air as effectively as I once did. In my teens, I could free dive to seventy feet and carry a conch to the surface - as a free diver yourself, can you imagine water so clear that you can see conchs seventy feet down? The water in Guantanamo was like that.

That was a lifetime ago. These days, I play with the kids retrieving quarters off the bottom of a swimming pool.

This is an article I wrote about the last time I actually needed a watch while diving - and I did not wear a rep although if I did it today I probably would just to test it (we had Randy's equipment to rely upon).

The Blue Hole

These days, I dive to retrieve an anchor, or whatever, generally diving alone (yeah I know). I am rarely underwater for more than thirty minutes at a time, and I haven't been down more than sixty feet in quite a while.

So, "yes," I wear reps diving, but "no," I do not recommend it to anyone who is new enough to the sport that they should care what others recommend.

As far as working on other people's watches, I really couldn't do that as I spend MUCH to much time screwing around with this stuff as is.

I am currently working on mastering the perfect vintage Rolex . . . did I mention that, once upon a time, I used to manage a machine shop? LOL

Bill

Share this post


Link to post
Share on other sites
Very informative post... Mod this should be in the KB indeed. Now where can one purchase testing machines...

TJ are those Bulova vintage ones that just work with airvaccuum and a soapbubble solution on the leak areas usable...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...A%3AIT&rd=1

or is that for rain and sneezeproofness :p

I wouldn't have a clue without knowing exactly how they work but the fact that they refer to "waterproof" suggests that they are ancient.

Someone probably should invest in a waterproof tester and check watches for people. You could send them your watch (without band/bracelet) with a return fedex envelope and a [?$] bill and they could test it and give you some peace of mind.

I don't have the time to be doing it, but it could be something someone else might want to do.

Bill

Share this post


Link to post
Share on other sites
Thor    0
do you know how many psi is 1meter diving?

1m = 0,1BAR + 1BAR from the atmosphere so we have 1,1BAR at 1m deep

Each 10 meter the pressure rises 1BAR... very easy to calculate

1 BAR = 14,50377 PSI ~15 PSI

129626-19597.gif

Here some additional infos/formulas in german (check point 4)

Click here

Share this post


Link to post
Share on other sites
offshore    28

Slay,

There are 2 answers to this.

If you want the total pressure ( Absolute-if I remember my diving terms) its 14.7 psi +1.47 psi=16.17psi.

However the gauge pressure ( deleting the already existing atmospheric... 14.7) is 1.47psi.

Its a simple equation, for each 33 feet ( or 10m) you descend, you add 1 atmosphere ( 14.7psi) to the existing surface pressure- ( 14.7)... so 1mtr = 1/10 of 1 atm or 1.47psi.

So from the other angle, at 1 mtr, you have 1.47 psi ( gauge) plus 1 atmosphere ( surface) (14.7)=16.17.

Hope thats clear... I haven't taught diving theory in over 20 years... but I can assure you the numbers don't change :p

I,m sure Bill will tell us if I,ve got my terminology wrong.

Offshore

Share this post


Link to post
Share on other sites
offshore    28
TJ are those Bulova vintage ones that just work with airvaccuum and a soapbubble solution on the leak areas usable...

or is that for rain and sneezeproofness :p

@KKS,

I have/had one of the Bulova testers, and they will give you an understanding that a watch leaks ( or doesn't) I have however seen someone post a simple test @ NAWCC, which is so easy, and achieves exactly what a Bulova test does.

1 Place your watch in the sun and get it hot.

2 Immerse the watch in cool water in a glass.

3 Look for a stream of bubbles, if you see same, immediately remove the watch from the water.

4 You have identified a leak... fix it.

This does not give you a "pressure" at which tested, just identifies a leak, as does the Bulova tester.

Simple physics, you have increased the internal pressure of the watch by putting it in the sun, immersing it in cold water, whilst reducing the pressure, creates a initially a differential of pressure internal vs external, ( until the cold water reduces and balances the internal pressure)

The differential ... SHOULD... create a stream of bubbles if the watch has a leak point. And as soon as that is seen, get the watch outa there, before the pressure balances, and water has an opportunity to start moving into the watch.

There you go, simple , easy, no guarantees, and certainly no ability to say " tested to X mtrs" or " X ft"

But a better test than no test, and you would have to be confident if it didn't leak, that you could shower, or surface swim with it. Or as Eddie puts it " Good for a 100m dash in the rain"

Offshore

Share this post


Link to post
Share on other sites
do you know how many psi is 1meter diving?

One meter? I am having a hard time picturing 1 meter diving? If I dangled my oldest son off the side of the boat by his feet, his wristwatch would experience 1 meter diving.

To answer your question though, one atmosphere (14.7 psi) of pressure is the general equivalent of 10 meters in depth or approximately 33 feet in SALT WATER. It is more like 34 feet in freshwater.

So, if you are asking me what is the relative pressure differential when something is submerged 1 meter, the answer is 1.47 psi.

If you are asking the total absolute pressure, you add 1.47 psi to the standard atmospheric pressure at sea level which is 14.7 psi.

Bill

Share this post


Link to post
Share on other sites
Tropic    0

Diving into 1 meter Deep water? :wounded1: Too shallow,

I would not recomend it!

Or Scuba Diving submerged 1 meter deep? Save yourself some money and Go snorkeling :snorkel::fish:

Ok serious know,

I do enjoy the Clear Seas of the Adriatic & Ionian.

I love the Med.

Share this post


Link to post
Share on other sites
bbob    0

TJ as you have tested the watches can you give some sort of list that shows at what pressure you have tested your reps.

On some sites I do see that some offer to put new seals etc in the watch and test is to 5 bars.

What does a standard not modified rep withstand as for pressure.

Share this post


Link to post
Share on other sites
RageRover    0
You are NOT seriously suggesting that People would trust their Asian REPLICA of A Divers watch,

After they Pressure tested It, and depending nothing less then their life (Who Cares About A Wet Replica when Youre Dead?) On It, While Scuba Diving!?

For the reccord, I am a certified diver and have been for over 13 years.

What’s wrong diving with an Asian rep? I've been wearing a $150 Seiko when I dive for at least 3 years (probably more like 4-5, I can't remember). When I became certified, my parents gave me a Heuer, which I wore until I got the Seiko. Why don't I wear the Heuer much? Its Quartz :(

If a watch is made well, if the machining is done well, gaskets are installed, there should not be a problem wearing it in the water.

Just because a gen Rolex is $5000 and a rep $300 does not mean the rep is not equally as water proof. The main thing I find with reps is that there was often no love when they are assembled (along with minimal to no QC). So if a gasket is forgotten, or a caseback not screwed down tightly, the attitude was probably "who cares?"

Many of the reps now have a high quality machined case. The tolerances are very good, just like gen. Look at IWC Ingie, Omega SO or Panerai for example. Many of the reps use the same/similar ETA movement as gens.

If a $50 plastic Swatch is water proof enough to dive with, then a $300 steel rep can be made resistant enough to water to dive with.

You should not rely on ANY watch, rep or gen. Gen fails too. This is why you always dive in a group, always have a “buddy”, and have a back up watch or dive computer (i.e. redundancy).

Share this post


Link to post
Share on other sites
geekybiker    0

One thing to remember about tested pressures and diving is that rated pressures are static pressures. IE the watch isnt moving. While driving you'll be moving that watch through the water, increasing the pressure it will experience at any given depth. IE a 50m rated watch wont always stay watertight at 50m. I personally would never take a watch rated less than 100m underwater with me while diving.

Share this post


Link to post
Share on other sites
rkdk    2

Just thinking does anybody know if a chronowatch would be less waterproof, than a non chrono?

Obviously the screw down chronos like the daytona and 187 dont count here.

I just have a hard time imagening a watch like the offshore, or the ingy would be waterproof, since the chronopusher dont seem sealed.

Share this post


Link to post
Share on other sites
offshore    28

Is a chrono less waterproof?

Than what?

If you are asking if a chrono has more chance of water ingress, the answer is YES.

It has potential failure points at the crown stem, the two pusher stems, the rear seal, and the crystal seal.

That's 5! ( POTENTIAL failure points.)

Now a Swiss company Mido, pioneered a watch that was the most "Waterproof"

It had a solid back, entry to the mechanism is via the crystal only, and it has just a single crown/stem. So, only 2 potential failure points! ( No it's not a chrono)

However, if the correct, designed and serviced seals, are not in place, and the watch has not been pressure tested, it probably will "leak"

Just as the chrono will.

So, a well designed and serviced watch, should not leak.

Unfortunately they still do.

You did ask about the difference between screw down, and pusher style chronos.

IF, correctly designed O ring seals are used on pusher style chrono stems, there is no more chance of them leaking, than screw down styles. Screw downs, are using a different sealing principle. ( Again, if the correct design/style is being used.)

Confusing,.... better beleive it... and the examples I have used are for genuine watches, designed for these activities, by watchmakers... not by some backyard operator, who thought putting an O ring there would be a good idea.

Offshore

Share this post


Link to post
Share on other sites
rkdk    2

Thanks offshore. That clarifies it quite a bit. I just cant really get my head wrapped around, how they would seal a chrono without the screwdown pushers.

i know they can, but how, i dont know.

thank god im not a watchsmith:-)

Seems like im gonna have to get my eod pressure tested.

Share this post


Link to post
Share on other sites
Brucelles    0

My gen Breitling chrono has non-screw pushers and is rated to 10atm/100m. tbh it doesn't feel right that the pushers still work under water, but I have used them to reset at 22 metres with no problems.

@KKS,

I have/had one of the Bulova testers, and they will give you an understanding that a watch leaks ( or doesn't) I have however seen someone post a simple test @ NAWCC, which is so easy, and achieves exactly what a Bulova test does.

1 Place your watch in the sun and get it hot.

2 Immerse the watch in cool water in a glass.

3 Look for a stream of bubbles, if you see same, immediately remove the watch from the water.

4 You have identified a leak... fix it.

This does not give you a "pressure" at which tested, just identifies a leak, as does the Bulova tester.

Simple physics, you have increased the internal pressure of the watch by putting it in the sun, immersing it in cold water, whilst reducing the pressure, creates a initially a differential of pressure internal vs external, ( until the cold water reduces and balances the internal pressure)

The differential ... SHOULD... create a stream of bubbles if the watch has a leak point. And as soon as that is seen, get the watch outa there, before the pressure balances, and water has an opportunity to start moving into the watch.

There you go, simple , easy, no guarantees, and certainly no ability to say " tested to X mtrs" or " X ft"

But a better test than no test, and you would have to be confident if it didn't leak, that you could shower, or surface swim with it. Or as Eddie puts it " Good for a 100m dash in the rain"

Offshore

I wonder about this:

You heat up the watch, thereby heating and expanding the air inside it, if there is a leak it leaks out and the pressure equilibrates with the outside pressure.

Then you drop it into cold water. The cold cools the case and thus the air inside it, which contracts and allows air pressure to force water into the case.

It sounds to me as though you will fill your watch with water.

Share this post


Link to post
Share on other sites
prince458    0

wow ... wow ... now i know why the sciences and any of the engineering programs was not for me ... i would prefer to pay someone for this information ... better yet at the prices of current reps low to medium range ... just get a new one

Share this post


Link to post
Share on other sites

×