Servicing a Doxa dive watch

I recently received this Doxa Sub 600T with the complaint that the watch would not run for very long. 

The owner had also complained that the bracelet end link didn’t fit tight to the case on one side, and when I removed the bracelet I found out why.  The spring bar just fell apart on my bench, so very fortunate this didn’t happen while the watch was being worn:

Opening the case, the ETA 2824-2 is seen:

Here the hands and dial have been removed:

Now I start removing the calendar:

Here the winding/setting mechanism has been removed:

Now to the top plate, and the ratchet wheel has been removed.  I wanted to point this out as here there is a boss that is part of the barrel bridge that the ratchet wheel rides on.  You can see the black material where the green arrows are, and this is material that has worn off the boss at the spot indicated by the red arrow.  This movement can wear a great deal here so one reason why regular service is a good idea, even if the watch appears to run well:

Carrying on with disassembly:

Here the base plate has been stripped of all parts:

And everything is apart now and placed by function in the storage trays: 

But they don’t stay there long as up next is the cleaning machine:

Here I am applying the braking grease to the mainspring barrel:

Here the new mainspring has been installed in the barrel:

And the barrel is back together as a unit and set aside ready for the movement at a later time.  The next thing I do is lubricate and install the balance jewels, and install the balance to check the hairspring.  Here you can see the spring as it goes through the regulating pins, and it’s too far to the right and touching the inner pin, where it should be centered between the pins:

Here the spring has been adjusted, with attention being paid to the overall centering/spacing of coils from above.  This required rotating the hairspring stud and also manually manipulating the spring:

Now the balance is removed and the assembly can begin, so here the barrel and barrel bridge is in place:

More reassembly:

Now we are at the point where the escapement needs to be lubricated, and the pallet stone I will oil is shown in the small blue circle:

After that is complete, I place the balance cock and the balance fires right up:

I then check and oil the reversing wheels, and assemble the bridge

 

So now to assemble the calendar:

Now it’s time to put this back together, so the dial and dial spacer are first:

Then the hands are pressed on, paying attention to the date change so that it’s within the tolerances:

Now the watch is cased:

And I install the auto-winding bridge:

And onto the timing machine for initial regulation:

Once that’s done, time to close it up and do some extended timing and power reserve tests:

The next step is checking the water resistance of this watch.  For this I use 2 machines.  The first is the Witschi Proofmaster S dry pressure testing machine.  This machine is set to the dive watch program, which first subjects the watch to a -0.7 Bar vacuum, and then a +10 Bar pressure.  The watch is constantly measured to detect deflection in the case, and through those measurements determines if the watch is water resistant.  Here the watch is ready to be mounted in the chamber:

And here the test is complete, and I have magnified the results screen and inset it into the photo:

But we aren’t done yet.  This watch is rated to 600 m or 60 Bar, so a test at 10 Bar won’t really tell us if it’s performing as it should.  For that we use a wet testing machine.  There is some risk with this second test, as the process basically involves trying to force water into the case at high pressure:

The watch is placed in the holder, and then into the test chamber.  The test chamber is filled with distilled water to the very top:

The lid is placed trying not to allow any bubbles inside the chamber:

The watch is tested at a higher level than it’s rated capacity, so for a 60 Bar watch, the machine is set to 70 Bar, or just over 1,000 pounds per square inch:

The watch is left at this pressure for 2 hours, then I come back and lower the pressure, and remove the watch:

The watch is dried off and placed on a heating station that heats the watch to 47 degrees C:

30 minutes later, I return and place a few drops of room temperature water on the watch crystal:

I wait a couple of minutes and then wipe the water off.  If the watch has leaked the inside of the crystal will have fogged, but this one is clean:

The bracelet was mounted and the watch returned to the client.

I hope you enjoyed seeing how a modern dive watch is serviced.  If you have any questions or would like to have your watch serviced, please contact me at archer.watches(at)sympatico.ca

http://www.archerwatches.ca/

Cheers, Al

Advertisement