Thursday, December 26, 2013

Oil Spill

The last thing I tackled this last quarter was to change the battery on an oil-filled quartz watch.  Whoever had attempted this in the past has let an air bubble into the case and the watch had stopped.

After installing the battery the watch was still not working.  I am used to working on these movements.  It's essentially the same watch movement we had to complete on our SAWTA 2 tests.  So i took everything apart and during the process I dinged the coil and ruined it.  Replacing the board was not an option because this is a special 3 volt board with a custom battery holder.

No big deal, we have plenty of extra coils around.  So then began the painstaking process of melting off the existing solder and epoxy and soldering on a new coil.  This is difficult because the wires are VERY fine.  After about a half an hour I was able to get a new working coil installed.

This process is incredibly messy.  There was oil everywhere, all over my bench and my tools.  It was a very strange feeling getting oil all over a newly cleaned movement as that's usually exactly what you are trying to avoid.  At least putting the movement back together was quick because you didn't have to worry about oiling anything.

Once back together and ticking once again I refilled with oil, vacuumed most of the air out and we now have a watch that only has almost microscopic bubbles suspended in the mineral oil.  I've not figured out how to remove those yet, I'm guessing a stronger vacuum pump would help with that.
Oil-filled watch, complete with bubble

Even with a new battery the watch did not run, it needed an ovehaul

My vacuum platform, made mostly from scavenged materials helped pull some bubbles out of the oil.  The air compressor's pump does not draw a very efficient vacuum though so it was not as effective as it should have been.  We need a proper vacuum pump.

Thursday, December 5, 2013


Three down,  one to go!
I passed my SAWTA 3 exam this week.  The test involves 4 parts:
1. Overhauling, repairing and casing of a 2824
2. 15 question theory
3. Case refinishing
4. Bracelet refinishing
Things went very smoothly this time around.  The only critique the examiner had for my watch was that I over-oiled the crown wheel and was a little light on the oiling for my lower balance pivot.  Besides that I got full marks!
The quarter is nearly finished, the last project I have on my plate is a cell change in an oil-filled quartz watch.   I am devising a vacuum system to make this simpler.  I will post soon.