REP WATERPROOFING

[RolexAddict 1]

 

At this time my knowledge and experiments are limited to Rolex rep watches and practiced on Daytona, Submariner GMT and Explorer models. These models cover all kind of cristal -sapphire and plexi- assembly and screwed crown systems on all Rolex sports models rep.

Except for the 2 kind of screwed crowns called twinlock and triplock patented by the Rolex company, and except for the screwed chrono pushers system, the various cristal assemblies and the screwed case back on Rolex reps are almost the same compared with the gen Rolex watches.

 

 

OVERWIEW OF THE CONCEPT

Before starting with "how to", procedure pics etc. and before to put a watch in water, I would like first to expose here my philosophy and point of view.

The purpose is not to immerge a watch and try to prouve its able to go 300 meters deep. It can. But I don't have equipment to test the pressure and give numbers. I can bring from time to time a watch to be tested by a shop who has equipment.

One of my Daytonas sec. at 6.00 was 22 meters deep in see water last year. One of my Beginmariner was 70 meters deep in a lake in French Alps mountains. Both run perfect still today.

 

One of my modded GMT Master was tested in a watchsmith lab. I told the guy to start with 50, then eventually 100 meters, no more with a plexi. He didn't listen, put 50, then direct 200 meters !!! and the watch was proofed and agreed for 200 m by the machine !!! I was really affraid for the plexi, but he didn't explose, its a gen plexi.

 

The last experiment was last week. I returned to this watchsmith lab. The guy is not a Rolex specialist, he doesnt know well the models. So I told him my watches are gen... My argument was I don't call for a Rolex AD lab because I didn't want to spend lot of money just for a pressure test. I came with my Josh's Beginmariner. It was already 70 meter deep in real conditions. The guy said he had problems with his compressor, no way to test to 300m but he will try the max pressure available. The Beginmariner was confirmed for 22 bars !

 

here, the photo taken by on of the employee with my little Lumix after the test.

I didn't have the right to go myself behind the client desk. I swear this is my Sub and there is no trick.

 

After these experiences I am sure a rep watch is able to go in deep water as well as the gen models.

 

The goal is to explain and allow to each member here to prepare a watch for a intensive use under wet conditions and without aprehension

This will be possible for each one of you with a minimum of tools and little skills.

Believe me, if during vacations you swimm with your Sub or SD, nobody around the pool will think or say you wear a fake. If you remove your Sub or SD before to go in water... watch educated people around would laugh

 

The goal is just to prepare and "tropicalize" a watch for serious use during summer vacations: perspiring, walk in heavy tropical rain, swimm in a pool or in sea water, car washing, fishing, water skiing, sailing etc.

 

Just to allow this :

 

 

 

SUMMMARY

1) PRESSURE FORCES, THE BASICS

2) BUILDING TECHNICS, TOOLS AND PRODUCTS USED

3) WARNINGS, CARE AND SERVICING A WATERPROOFED REP (also good for gen)

==============================

 

1) GENERAL CONSIDERATION AND WATER PRESSURE

I am not a teatcher or a guru, just try to make it very simple and stop the fear and the myth about rep watches and water.

Remember JohnG topic, - http://www.replica-watch-guide.net/forum/i...p?showtopic=665 -

Everything he wrote is the true. He also pointed out the difference between static pressure and the real under water conditions.

My following considerations are not 100% professional, but the approach is logical, and it works fine.

What is the water pressure ? just the forces exerced by the water weight on a soaked object. Altrough the Rolex company is still claiming for unique professional tools and perpetuate a myth, now for less than 200 USD you find quartz chronos proofed to go 300 meters deep in water.

300 meters is nothing for a watch. Exemple : If you build a bigger DSSD with a bigger case and a bigger rounded sapphire the watch will be good for 10.000 meters, no necessary to be a enginer or physician to understand this.

Water pressure effect on immerged objects goes proportionally with the size and thickness of these considered immerged objects.

For a submarine, 300m deep is a lot. Because for 150 meters long and 20 metres wide, its sides are only 20 or 30mm thick. But if you compare the building specs and proportions, a 40mm diameter watch construction looks like a 150m long submarine who would have 10 meters thick sides...

 

So water pressure is not so terrific for a watch, if you think in advance what and how deep you want to immerge.

And I am not completely convicted by the Rolex tech. arguments about the helium valve on a SD and diving in satured atmospheric conditions, this is just personal considerations.

I say this because I can understand the helium gaz accumulation in a Batiscaphe type submarine, but a watch with a 1 or 2 cubic.cm inside space... volume... hum

O.K, I . I am not a specialist. And I admit Rolex watches are great. And to expensive.

 

But I want to add this: The founder of ChronoSwiss has written "the Art of the Perfection is not to add features, but to keep everything simple"

 

PRESSURE CONSIDERATIONS

The water weight is mesured in atmospher, from 10 to 10 meters. 10 m is one atmospher (ATM) or one BAR. A watch proofed for 30 ATM or BAR is theorically good for 300 meters.

 

The mesured weight of water is taken into consideration starting at 1 ATM, so 10 meters. This is peanuts as its the same weight exerced at see level, as we support the weight of the atmospheric mass.

Between 0 and 10 meters deep the weight of the water exerced on a human body or every soaked objects is 1 kilogram for 1 square centimeter.

At 100 meters deep it will be 10 kg/sq.cm, 300m = 30kg/sq.cm etc.

This theory is the hydrostatic pressure called the relative pressure.

 

But in fact for diving and for watches we have to take in consideration the absolute pressure who is the water weight + the atmospheric weight.

That means :

At 10 meters deep the total weight will be 2 BARS, so 2kg/sq.cm : 1 X 1kg + 1kg for the atmospheric weight

At 20 meters deep the total weight will be 3 BARS, so 3kg/sq.cm : 2 X 1kg + 1kg for the atmospheric weight.

Starting at 30 meters, the atmospheric pressure added will be only 1/5 so the weight will increase like this: 3 BARS + 20%, so 3,6kg/sq.cm.

For a watch, the critical surface exposed at the water weight is the cristal. That's why gen vintage Rolex (exept SD) were rated only at 200 meters, the plexi is more fragile than the sapphire glass.

At 300 meters deep, the sapphire of a Sub will support a weight of plus or less 36kg/sq.cm.

This means, on a Rolex sport model, the sapphire diameter being 30mm, the cristal surface is 7 sq.cm. 7 X 36kg = 252kg dispached on the entire surface. Your rep saphire will resist without problem like a gen.

You can press very hard with your 2 thumbs and get almost 252 kg of pressure. The saphire will resist. The plexi can brake.

 

Have a look here and read, its really interesting !

http://www.gizmodo.com.au/2007/12/jaegerle...ng_watch_m.html

 

If you want to dive with a rep vintage Sub or SD, its IMPERATIVE to change a for GEN OR AFTERMARKET dome plexi. THOSE ON REPS ARE NO GOOD, FRAGILE AND ASSEMBLED WITH A POOR GLUE, THEY HAVE TO BE REMPLACED.

 

 

Only 7 sq.cm surface for a Rolex cristal. The presure is equally dispached. It will not brake, the pressure dispaching is like if you compare with a fakir lying on a bed full of needles. One needle would hurt him.

 

 

About the stress caused by a quick change of pressure : yes this is a problem, but the failure will not come from the crown nor the case back, but only from the type and quality of the cristal assembly. This will be explained in the 2th chapter.

 

The sea water is more heavy than the fresh water, the reason is the weight of the salt. 1 liter of fresh water = 1 kg. 1 liter or sea water = 1,025kg.This means in fact that at 300m deap in sea water the weight applied on your cristal will be a little more than 252kg. On again, the sapphire cristal on a rep is strong enough.

 

2) BUILDING/ASSEMBLY TECH.

 

TECHNICAL

Before any experiment, just think a little about the Rolex rep construction and compare with gen. Althrough gens are high tech. building, the rep construction is no so bad. Simple, but efficient and everything sounds O.K and easy to prepare a rep for waterproofing.

 

Here, the Daytona building, not a lot of parts, but very well done and 100% waterproofable

 

 

some various rep gaskets

 

The gen Daytona assembly, o.k, I admit this is serious stuff...

 

All rep and gen chronos have the same feature for the pushers : a pin passing through the case when pushed... I am working on a waterproofed chrono pusher allowing to press the pushers under water. International O.M.P.I patent pending right now. I will sell the idea. Very simple in fact. Look at this pic and think about, not a big deal...

 

THE METHOD

First, before any intervention, the movement has to be extracted out of the case. I make a water resistance test with the watch background features.

But taking the watch and immerge it in water is not really good. The problem if you do that, you will have a lot of air bubbles coming from the bezel, bracelet etc.. you will never be able to see eventual flaws from critical spots like the cristal and his plastic ring or the case back, and finally, the risk is to ruin the watch...

Also

 

_A) CHECKING AND PREPARE THE WATCH FOR A WATER RESISTANT TEST :

I disassemble the bracelet, the bezel, the bezel insert also as he need to be re-glued with a good glue. I open the case to remove the entire movement with the dial. After that, I get a basic empty case ready for a dive. I grease the case gasket and screw the case back tight. The same with the crown : a little among of grease on the rings and threats and I screw tight.

The watch is now ready to take a bath in a tank, and to check for bubbles. No risk, its a empty case.

Then, I submit the watch to a stress test with hight pressure water jets like in spa or jacuzzi. Finally, the watch stay a overnight in the tank full of water.

If the test is good, I deduct the watch is good for swimming with zero risk. I put back the movement inside and use teflon and marine grease to seal everything right.

 

In case of bubbles : bubbles will come ALWAYS FROM THE CRISTAL, never from the case back, crown or pushers if everything is screwed tight. In such case, the cristal has to be removed and glued. Its not really a good thing to try to change the gasket as trying to adapt gens, often they don't work on rep. Also a good cristal press is expensive and need good skills. Not really easy to restack properply a cristal. So, for a rep the best way is the use of glue. (see the folowing explications in C chapter)

 

Here, a Daytona case ready to be soaked for the test

 

High stress in water

 

Here, the stuff I use to coat o-rings and cases back and crowns threats : I mix teflon paste, high temp and marine grease from various brands

 

_ CHECKING AND PREPARE THE WATCH FOR A DEEP DIVING TEST :

No kidding with this: I apply the same rules than above, then I bring the prepared watch to a watchmaker and pass the pressure test. (IN CASE OF BUBBLES : see the folowing explications in C chapter)

 

Also to close tight the case its necessary to use professional tools, no playing with ruber balls or duke tape. The case back has to be closed with a equal torke on all the diameter. This will assure a 100% efficiency for the gasket

 

For this I use a wise -don't be affraid-

 

As I fix a case holder on it, the 4 nylon rings will protect well the watch body

 

Then I close tight the case with the right tool

 

 

C) HOW TO PREPARE THE WATCH IN CASE OF BUBBLES OR WHAT I WILL CALL "BASIC WATCHPLUMBING"

As I told, the cause of troubles will come always from the cristal assembly. The Rolex rep crowns and pushers works quite like the taps in your bathroom. I have observed all types of crowns construction, also Daytona pushers.

 

Here, the patended gen Rolex twinlock and triplock for crowns

another drawing

 

Here I have made a drawing from all types of screwed stuff on Rolex reps:

 

Water cannot penetrate inside if these crowns are well screwed. Even the DD/DJ/GMT/EXPLO type without the outside tube o-ring. Like a tap it need just to bee light coated with marine grease from time to time. The rubber ring inside the crown body is very efficient. Same for pushers. The screwed part when screwed tight is in contact with the case. The double little rubber o-rings on the pins are efficient to,

 

Important: THESE SPECIAL WATCHMAKER GLUES RECOMMENDED AND SOLD AS PROFFESIONAL FOR WATCH CRISTALS DOESN'T WITHSTAND HOT AND A LONG TIME IN WATER

If I decide to glue the cristal, I use 2 kinds of ARALDITE epoxy. One cristal clear for the background cristal holding, then another type to fill up the space between the case metal and the cristal. I do this especially with gen or aftermarket plexi, as the surface who holds cristals on rep cases is wider. Also when you remove the cristal gasket you have also a space who need to be filled. These 2 epoxies withstand 120°F and are used by Airbus to glue aircraft parts, so for a watch, no problem.

 

 

How the glue is applied :

In white, the original factory plastic ring. In red, the gluing action. No way for water to penetrate.

Also note the difference of building between rotating bezels and fixed bezels on Rolex reps. To remove a cristal on a fixed bezel case you need first to remove the bezel by insering a blade between the case and the bezel, then lift gently. Then push the cristal out.

 

 

4) WARNINGS, CARE AND SERVICING

 

First remember :

_A) A waterproofed watch has to be immerged in water or tested in pressure test equipment with CROWN AND CHRONO PUSHERS TIGHT SCREWED.

 

_ On a waterproofed watch, the hazardous area where water can come easily in, and the most fragile assembly IS THE CRISTAL. Especially press assembled sapphire cristals. There are NO PROBLEMS with glued plexi and sapphires. Under the condition you have used SPECIAL EPOXY instead of REGULAR GLUE.

 

You need to take special care with a waterproofed watch. Avoid chocs/knocks, especially chocs on the cristal area. Avoid to go in hot tubes, sauna or just hot water with a sapphire cristal watch. Remember: the trick to push out a stubborn cristal or a rep factory glued plexi is to let it soak in hot water before...

 

The gasket is in a kind of soft plastic and this one could get softer then loose simply under vapor and temperature elevation actions. Same things for a glued plexi. Glues used are not O.K and they don't withstand hot.

Avoid also violent pressure variation like from jumping or diving in a pool from a diving board. (remember the stress gererated by fast movements in water) This is the best way to get the fog under the cristal... even with a gen.

This is also the same for case back and crown o-rings.These are hot sensitive and fragile.

 

About care and servicing :

The crown of your watch should be always screwed on to avoid dust and wet to penetrate. From time to time put a little grease on the crown threats and in the crown cavity. Use a toothpick for this or a needle. Screw tight the crown before you go in water. When finish, after a pool or a beach day, unscrew just a little the crown, just to allow the o-rings to relax and reduce the pressure. This is good to preserve them. Like a tap at home, never close it to tight for a long time, or the gasket will be ruined very fast.

 

A waterproofed watch will never stay waterproof for the life. For my reps I use to swimm with, every 6 months I open the case backs, wipe off the old grease, check all rings -change if necessary- I check also the cristal assemblies, then coat all rings and theats -case back, tube and crown- with fresh grease/teflon.

 

IMPORTANT:

Beware with cheap replicas. Even if a rep looks fine, you mostly get a piece of shit under 150.00 USD. Its not only a matter of Chinese movement instead of Swiss, the construction material is also inferior. Most of the time you don't get 316L stainless steel who is THE INTERNATIONAL REFERENCE for watches and knifes industry. Most of the time you will get iron cast or MIM (Molded Injected Metal) or "pot metal" with a very thin coat of "kind of" nickel. THESE WATCHES WILL RUST IF YOU GO IN SEA WATER !!!

Beware also with SS bracelet, as many are 316L SS but links and clasps are assembled with polished carbon steel pins or screws who will also rust.

 

Hope you liked these explications, I will regulary edit this and make corrections,

And don't hesitate to say if something is no clear, of seems vrong, nobody is perfect.

Edited March 21, 2009 by RolexAddict

[greg_r 81]

Absolutely amazing article RA!

 

If you don't mind, I'll move it over to the Watch repair section so that I can sticky it with your other threads.

[omni 6]

Great article RA. Thanks.

[AllergyDoc 40]

Bravo!

 

Lot's of math, though. Took me back to school.

 

Once a crystal is glued in, is it difficult to change if it gets broken?

[Luthier 1]

OMG...............................................

I'm speechless.

Just fantastic!!!

THANKS, RA!!!!!!!!!!!!!!!

[RolexAddict 1]

Thanks guys for your interest,

 

Bravo!

 

Lot's of math, though. Took me back to school.

 

Once a crystal is glued in, is it difficult to change if it gets broken?

 

Not really difficult, it just takes time to remove all old glue get a clean case

Broken plexies are problematic to remove when glued with epoxy, as they brake in lot of little parts. In this case I use a Dremel with dentist tools to remove all little particles attached to the case. Epoxy glued sapphire cause less trouble when they need to be removed.

[KBH 7]

Very nice write up RA.

 

I have one small disagreement, though.

 

You say:

 

"also remember:

the weight of the water is only exerced VERTICALLY. The max of pressure on a cristal will be effective only if you hold your watch horizontaly."

 

This I believe is false. One of the laws of mechanics is that when water is at a state of rest, pressure is equal in all directions. That is that pressure doesn't know up or down.

 

If fact, It would be a minuscule difference, but there would actually be slightly more pressure on the bottom of the watch since it sits at a deeper depth. Just not enough to matter.

 

 

Minor point I'm sure, but otherwise very good reading. Thanks.

[onzenuub 307]

[AllergyDoc 40]

Pascal's principle?

[RolexAddict 1]

Very nice write up RA.

 

I have one small disagreement, though.

 

You say:

 

"also remember:

the weight of the water is only exerced VERTICALLY. The max of pressure on a cristal will be effective only if you hold your watch horizontaly."

 

This I believe is false. One of the laws of mechanics is that when water is at a state of rest, pressure is equal in all directions. That is that pressure doesn't know up or down.

 

If fact, It would be a minuscule difference, but there would actually be slightly more pressure on the bottom of the watch since it sits at a deeper depth. Just not enough to matter.

 

 

Minor point I'm sure, but otherwise very good reading. Thanks.

 

You pointed out a interesting problem :

This I believe is false. One of the laws of mechanics is that when water is at a state of rest, pressure is equal in all directions. That is that pressure doesn't know up or down.

I had lot of discussions with watchsmithes and divers. This is the theory they told me. But thinking about, what I wrote can be vrong,

We can all together check and search for water weight physic to bring corrections, if any else member has a idea,

 

My opinion:

This subject will stay here, and all members are invited to contribute, this topic stay open and has to be updated with critics, corrections, sugestions etc.

[Massimo 53]

Great article. I applaud the logic applied to the problem: test first with the movement and dial assembly removed - simple but effective.

 

If I read you right, sometimes you will get lucky and not need to re-glue the crystal. Have you found that very often?

[oscarmadfish 0]

outstanding

[onzenuub 307]

outstanding

How do you know ?

[oscarmadfish 0]

one means outstanding post RA

[KBH 7]

Very nice write up RA.

 

I have one small disagreement, though.

 

You say:

 

"also remember:

the weight of the water is only exerced VERTICALLY. The max of pressure on a cristal will be effective only if you hold your watch horizontaly."

 

This I believe is false. One of the laws of mechanics is that when water is at a state of rest, pressure is equal in all directions. That is that pressure doesn't know up or down.

 

If fact, It would be a minuscule difference, but there would actually be slightly more pressure on the bottom of the watch since it sits at a deeper depth. Just not enough to matter.

 

 

Minor point I'm sure, but otherwise very good reading. Thanks.

 

You pointed out a interesting problem :

This I believe is false. One of the laws of mechanics is that when water is at a state of rest, pressure is equal in all directions. That is that pressure doesn't know up or down.

I had lot of discussions with watchsmithes and divers. This is the theory they told me. But thinking about, what I wrote can be vrong,

We can all together check and search for water weight physic to bring corrections, if any else member has a idea,

 

My opinion:

This subject will stay here, and all members are invited to contribute, this topic stay open and has to be updated with critics, corrections, sugestions etc.

 

 

General Phenomena connected with Water in a State of Rest-Pressure as Depth or Height of Water Column.

 

Unfortunately I can't paste the diagrams with this but I think you'll get the idea.

 

Take a column or pillar made of blocks of stone or of bricks superimposed one upon the other and resting upon the ground as a base at a a, fig. 91. In building up the column or piling the blocks or bricks one upon another, when the first brick, as b, is laid down, the

 

 

 

TO,

 

Fig. 91.

 

ground surface of a a covered by the brick will have a pressure put upon it—in the vertical direction indicated by the .arrow i—equal to the weight of the brick b. When the second brick, c, is placed in situ, the brick 6 will have to bear the pressure of that brick, and the surface of soil, a a, the weight of two bricks, b and c. When the third brick, d, is placed on c, the brick b will then have the pressure equal to the weight of two, and the ground surface a a of three bricks. And as the bricks necessary to form a column of a certain height are laid in succession, the pressure on the ground a a covered by the surface of the brick b will obviously increase. The higher the column the greater the pressure on the base, as the height a k will give a much greater pressure than when the column is only the height of am. We then in like manner suppose a mass of water confined in a vessel or in a deep reservoir or tank to be made up of a series of globules or molecules, as in fig. 92, at a b, each placed so as to form vertical columns, as a b, the lowest, b, of which will have a pressure or weight upon it equal to that represented by the weight of the wh.ole series above it. In round numbers, for every foot of depth of a mass of water measuring one inch square in section there is a pressure exerted vertically of half a pound, so that for every thirty feet of depth there is a pressure of fifteen pounds on each square inch of the bottom upon which the water column rests. We have already in a preceding paragraph shown that the pressure of water is equal in all directions. It thus follows that the pressure of a molecule or a set of molecules is exerted in an upward direction, as in that of the arrow a, fig. 93, tending to force the molecules b, c, d, upwards; and this just as forcibly, so to express it, as the

 

 

 

Fig. 92.

 

pressure in direction of arrow e tends to force the molecules f, g, h, downwards, or the pressures in direction of arrow i or arrow k, acting laterally but in opposite directions, tend to push or press the molecules I and To from left to right or from right to left. Some youthful readers will have a much readier conception of the fact that the pressure of water acts in a downward direction, as in that of arrow e, than of the fact that it acts in an upward direction, as in that of arrow a. But the difficulty will vanish if he considers that, unless the molecule b had a power, so to say, to press or push upwards, as in direction of arrow a, it could not possibly support the weight of the molecule c, or this molecule support molecule d. And it is just because the pressure is equal in all directions—downwards as at arrow e, to right as at arrow i, to left as at arrow k, and upwards as at arrow a—that there is a balance of pressure, and that water remains at rest within confined spaces. And as the pressure is as the depth, it follows that the pressure on the bottom of a vessel or of a reservoir, as a dock, is precisely the same where the depth is equal, whether the area of the surface of the water is only a few square feet, or an acre, or the bed of the wide ocean. If it were not for this beneficent law, man could never execute his embanking work to keep water from flowing over cultivated districts—never construct his dock by which he shelters and accommodates ships of all kinds and sizes. For if the law were not so, and the pressure were in some way influenced by the mass of water laterally or of greater surface, the pressure of the ocean or even of a wide river or estuary would be so enormous that no work

 

Fig. 93.

 

of man could possibly resist it. But with the fact that pressure is as the depth only, he finds the pressure exerted upon a sea wall facing the wide extent of the Atlantic no greater than the same depth of a mass of water which extends only a few inches laterally or horizontally from the face of his wall. This latter term, horizontally, brings us to the next truth in hydrostatic science, named in next paragraph.

[KBH 7]

P. S.: Last post was from:

 

The Technical Student's Introduction to Mechanics: Being a Series of Practical Papers Showing the Leading Principles of Physical Science ...

By Robert Scott Burn

Published by Ward, Lock, Bowden, and co., 1892

Original from the University of Michigan

Digitized Jun 9, 2007

544 pages

[JohnG 41]

Very nice write up RA.

 

I have one small disagreement, though.

 

You say:

 

"also remember:

the weight of the water is only exerced VERTICALLY. The max of pressure on a cristal will be effective only if you hold your watch horizontaly."

 

This I believe is false. One of the laws of mechanics is that when water is at a state of rest, pressure is equal in all directions. That is that pressure doesn't know up or down.

 

If fact, It would be a minuscule difference, but there would actually be slightly more pressure on the bottom of the watch since it sits at a deeper depth. Just not enough to matter.

 

KBH is absolutely correct. It makes no difference whether the watch is held vertically or horizontally - static pressure is exerted equally in all directions.

[alphakazi 0]

awesome contribution RA - makes me want to waterproof one of my reps now - great idea testing without the movement inside - so simple yet overlooked

[RolexAddict 1]

o.k KBH, thanks for the findings, and I am sorry for the mistake, I will edit and put the correction.

 

 

If I read you right, sometimes you will get lucky and not need to re-glue the crystal. Have you found that very often?

 

Thats right. Most of the time the factory stacked cristal is waterproof, even with a pressure test

Only one time for a Daytona I got bubbles , but I noticed the bezel and cristal were not very well seat on the case.

But remember, on vintage watches plexi has to be remplaced, not enough thick and the glue used doesn't withstand water

[trailboss99 994]

Exelent post RA, as usual.

Kinda a lot simpler than a lot of folk would have us belive hey? The boys are correct on the water colum bit tho. It's a tricky concept to grasp.

Post of the month for shure! Thanks for the effort you put in to bring us this one.

 

 

Regards, Col.

[offshore 0]

As I read through this, I had copied the "pressure" quote to comment, as I was sure it was incorrect... as has now been agreed.

Having dived (deep-frequently), and spent a fair bit of time playing with crystals/plexis, I would make a couple of comments.

If you opt to remove the press fit seal (which I agree is a great idea) then you must remeasure the crystal/plexi to be fitted and fit another a few sizes up (depends on the seal thickness)

It is a backward step, to think that glue will fill the gap left after the seal is removed.

I find replacement crystals/plexis, will be +1mm bigger to have a neat fit (depends, as stated, on the seal thickness.)

For a glue, I use Loctite 358, which is a UV cure glue. It is a joy to work with, it is "thin", (almost like water) and easy to spread. Any surplus can be wiped away before curing. It is easily removed after cure, with acetone. I tend to run a small amount around the crystal seating area with a toothpick, go back and wipe off any "shaky hand" spills/overflow, and insert the crystal, which should be a neat fit, but not tight. This insertion tends to overflow more surplus glue, which is then wiped away.

Then it is placed under the UV lamp, or in the sun for a couple of hours.

Then a further 24 hours to cure properly.

You can then get a cottonbud, with acetone, and go back and clean up any "mess".

 

To summarise, it is no good, removing a press fit seal, and using the same plexi. The glue is NOT a filler, it is an adhesive, and expecting it to "fill" out the area between the case and crystal edge, is frankly, a nonsense.

Have to agree, that the majority of failures I see when pressure testing, are crystal based, although I do see pushers as a weak area, as a lot don't have properly designed seal systems.

 

There is a great little publication " The Watch Crystal Encyclopedia", put out by Norman Helfland, (who has a watch parts business in Florida) which discusses all these things, and much more.

Another great reference, is Henry Frieds' "The principles of waterproofing Watches"

 

Nominally, there are 3 areas, water can enter a watch.

Crystal, stem, and rear seal. (Pushers excepted)

If the watch has even reasonable tolerances, and some form of seal at stem and rear, and the seals fit, are undamaged and lubricated, the chances for water ingress are remote. So it then becomes a matter of making sure the crystal is fitted and sealed properly.

It's not bloody difficult to build a waterproof watch, and not much more difficult to make one waterproof...as long as the original design tolerances are good, and a decent sealing system has been used.

Hope this helps.

Offshore

[RolexAddict 1]

It's not bloody difficult to build a waterproof watch, and not much more difficult to make one waterproof...as long as the original design tolerances are good, and a decent sealing system has been used.

Hope this helps.

Offshore

 

 

 

Yes, Master Offshore,

 

my article is just a piece of shit, I will delete it, shame on me

You write exactly what I wrote,

 

Let me a little time to give you a consistant answer about using glues and tell you the difference between cristal materials

[KBH 7]

Question for Offshore:

 

How does acetone and plexi react? Seems like not a good combination.

[RolexAddict 1]

First, the difference between cristals (watch glass surface for nobs):

 

1) Sapphire

2) Plexiglass

 

For a sapphire construction:

On reps, if the factory building is good after a test, its not necessary to remove the cristal. If no good, I remove it, I use the same but I fix it using special epoxies who are excellent sealers, as replace the original is no good and reps have the same specs as gens. Difficult to adapt gen O-rings.

 

I already told this

 

For a plexiglass construction :

On reps, they are glued with a bad glue.

Even if the watch pass a test, these glues used don't withstand heat, steam and water.

 

I have a good experience with glues. I use stuff who is isued from the latest epoxy technology (nylon derivative) and used for gluing and sealing parts on aircrafts and glass fish tanks. Epoxy I use is WATERPROOF it has a skin-tight molecular struture. It hold tight and seals at the same time on all well prep material like steel/steel, steel/glass or steel/plexi. Sometime also a mix epoxy with atomised SS or tungsten to fill space between the case side and the cristal. No issue for water to find a way. To fill empty space between the cristal and the case side, I apply the same technology like for bedding action on hunting riffles for accuracy.

 

Here, the cut shows the factory assembling :

The cristal rest on the case and is sealed with the plastic ring (in white).

 

If I glue, I use first a clear epoxy just to hold the cristal in place (in red onthe pic). I have 10 minutes to work, then it cures in 2 hours. I use a tooth pic for this. Then the empty space is filled with a other kind of epoxy, white color -in yellow on the pic-.

This product has a 16 hours time to cure. Believe me, to remove this you need a dremel and hight speed carbide tools. This job withstand hot, vibrations, acid, etc.

No way for water to penetrate.

 

Here, the job done on a Retro Edition GMT case, I removed the sapphire to put a plexi like on the first 116750 models

you can see the ivory color of the cured epoxy around the plexi

 

Here the job done on a Daytona case. This construction allows a generous among of epoxy, running down on the right. No problem, I have enought clearence to re-stack the bezel.

 

So please, constructive critics are welcome, but don't piss me off telling I wrote shit. What I wrote is more than 6 month continually research and experiments.

[offshore 0]

@RA,

I think your article is a wonderful piece of work, and agree with almost all you have said.

However I don't believe trying to "fill" out the area left when removing a crystal seal, with an adhesive, will offer the best solution. Sure, it can be done, and made to work, I have done it myself on some occasions, but in the abscence of an ability to pressure test that seal area after gluing, the chances of a leak are present.

So my comment was more a caution to those attempting to waterproof their watches, that without a final pressure test, this seal area, may become the point of failure.

I have seen and worked on many watches, that due to unbelievably shabby tolerances, would never be able to be made waterproof, no matter what was done! And not necessarily reps either....some of the cheap quartz cases from China, just aren't even substantial enough to not flex and leak under the pressures involved.

Offshore