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Posted by Esslinger Staff

We’ll begin with clarifying the meaning of waterproofing. No watch can be fully waterproof, the term water proof in a watch is illegal to be used in the USA since the 1960s. Water resistant is what is used today, and that can mean from a splash in the water fountain to a dive of 600 meters. We are going to make sure that watch, any watch, diver or not, lady’s or men, can be water resistant to a maximum possible. Watchmakers normally list in the dial or in the back of the watch to how deep a watch can be submerged, this is noted in bars or meters.

This process would ensure that a regular watch will be water resistant, better than when it came out of the factory. We will return to diver’s watches later. Let’s take an everyday watch from anybody – Fossil, Guess, even Timex. We replaced the battery and now we want to be sure that this watch will be as water tight as possible can be.

Tools Needed:


Step 1

Open the watch back.


Step 2

Check the O-ring or gasket and replace if it is needed. We place the new or old gasket in Gasket/O-Ring Lubricator, and leave it there while we continue with the watch inspection.


Step 3

Clean the back of the watch carefully, use q-tips with silicone, and make sure that both the watch back and watch case are free of any dirt.


Step 4

Remove the stem and crown, and clean the case tube ( if any) and the crown . If the crown is damaged, it needs to be replaced.


Step 5

After cleaning the crown and the tube (the hole in the case), apply silicone in the crown and parts of the stem. Make sure that the stem and crown are back in place in the watch and are functional.


Step 6

Clean the crystal of the watch and inspect. There should be no cracks or damage to the watch crystal, if any are found the watch crystal should be replaced.

If you replace the crystal, reset it with epoxy or similar cement to provide maximum water tight seal.


Step 7

Now that the crystal is either clean or new, so we get our The Rocket Glue, G-S Crystal Glue and we go carefully around the crystal and the case, applying glue on the edge. You only need to use a very small amount of this glue. The purpose of this is only to seal little imperfections that either the crystal gasket or the existing crystal glue may have. Let it dry.


Step 8

Now Remove the gasket from Gasket/O-Ring Lubricator, the gasket or O-Ring should covered with silicone. Place it either in the groove of the case, or in the back of the watch.


Step 9

Apply more silicone to the back and the case and close the watch.


Step 10

Set the watch and look for any glue or silicone left over and clean it.


If everything is done as mentioned, a watch water resistant to 3 Bar would probably be resistant to 4 or 5 in control environmental A.K.A. Bergeon Waterproof Tester.



Diver’s Watches

Let’s define what a diver’s watch is and more important what is not a diver’s watch: 99% of Chronograph watches are not diver’s watches even though they are sold as if they were. Buttons are very difficult to reseal so the more functions there are, the more places water can enter into the mechanism.


So if you work on these watches, you should warn the customer that you can’t be responsible for it.

Plastic watches, like Casio watches with a metal back and four screws, may be water resistant when they are sold, but when the battery is replaced, it is impossible to reset the screws with the right pressure – plastic case and metal screws are not a good combination. It becomes dramatically less water resistant after the battery has been changed, therefore you should not guarantee it will be water resistant after working on one.


A diver’s watch should have no functions. If it does have functions, all the buttons should be screwed in, like the crown and also the back to prevent water leakage. So we are going to change the battery and reseal the watch. The process is very similar as done before, everything needs to be cleaned; everything needs to be checked. All the buttons need to be removed and cleaned and lubricated with silicone, all the gaskets.


Most of the moisture in the watches comes in through the crown and the crystal, more so in a diver’s watch. We need to make sure that the crown gaskets are in good condition, that the crown is screwed back in the tube, the PPC gasket in the crystal is in good condition. The rocket glue will fix little imperfections, but if the gasket is damaged, it definitely needs to be replaced.


If you do everything I have written, the Bergeon Waterproof Tester tool should prove that there is not a leak in the watch – and can be a selling point tool or something to prove that your work was done right and impress your customers.

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