Vintage Omega Seamaster – Omega 285

I was speaking with a fellow watchmaker recently and we spoke about the fact that timekeeping results are not a reliable indicator as to the quality of the service you receive This alone does not answer the question whether or not your watchmaker has performed a ‘good’ service and given your watch the attention it deserves. I decided to outline the process of a full overhaul when a watch makes its way through my workshop. And the quality of service you should be receiving from your watchmaker. Here we have an Omega 285.

The watch came in looking a little worse for wear. The crystal was marked and the crown was completely worn away.

First, I need to un-case the movement and asses the damage. The dial and hands show signs of age, but they will be left as is, apart from some light cleaning of the hands to bring their luster back.

The watch is dismantled and broken down into sections. The parts we know we need such as a new mainspring (standard with every overhaul), crystal and crown are assigned to the watch. The dial and hands are stored for safekeeping.

Once the dial was removed the problems can be seen. There is lubrication that has ‘crept’ all through the movement. Thankfully, none of that lubricant made its way to the dial and hands. Whilst this watch had not been serviced in a long time, this picture shows the dangers of judging a service by timekeeping alone. This watch could in theory keep good time in such a condition, but could have disastrous long time consequences if the excess oil makes its way onto the dial of any watch, but especially a rare, important or sentimental one. New watches and parts can be replaced, vintage ones cannot.

The oil on the back of the dial.

I now flip the movement over and get to dismantling. As we dismantle the movement, the various functions such as escapement depth and end-shakes are checked. All the necessary adjustments are then made before the watch is cleaned.

More dirt and oil.

The movement is slowly stripped down, carefully checking each component as I go. We are looking for wear or damage to any part.

With all the bridges dismantled we can see the gear train.

We can now remove the dial-side components.

The barrel is opened and then the mainspring can be removed. Note how dirty the mainspring and barrel are.

Mainspring now removed.

All the jewels and bushing are ‘pegged out’ to make sure that the old lubricant is removed and makes life for the cleaning machine a little easier. Dried up oil can be stubborn and difficult to remove.

After the components have been thoroughly inspected it is time for the movement to go though the cleaning machine. It goes through a 5 stage cleaning process. One cleaning cycle, three rinsing cycles and heating cycle.

Once the movement is clean we lubricate the balance jewels and make sure the balance spring is flt and centered. It is important to do this after cleaning, as dirt and oil could have made its way onto the balance spring which would give us a false visual. When the spring is properly adjusted, we can move onto the next step.

We can install the new mainspring in the barrel. New mainsprings do not need to be lubricated, as they are treated at the factory. However, the seating for the barrel arbor must be correctly lubricated. Also, an automatic mainspring needs to have the barrel wall lubricated so that spring is able to slip around the walls of the barrel. This being manual wind watch makes that unnecessary.

The endshake of the barrel is then adjusted by using the lid. The endshake of the barrel arbor between the drum and lid needs to be minimal, but sufficient.

The barrel is then closed using this specific tool, NOT a pair of tweezers.

Next we can install the click and spring, being very careful with the small, delicate spring.

Next, we want to make sure we epilame the escapement, and a other necessary components so the lubricant stays where it should.

We can then put all the gear train components in place.

And then install the train bridge.

And then the barrel bridge, ratchet wheel and crown wheel. We can also install the over 4th wheel at this time, which is the wheel that engages the pinion which the seconds hand sits on. We will also lubricate the gear train as we go.

Now we want to turn the movement over and install the cannon pinion, and lubricate the gear train pivots on the dial side.

Gear train pivots should be lubricated sufficiently, but neatly, making sure no oil is allowed to come up onto the seating of the jewel. In horological terms, lubricants should only be on surfaces that have friction, no where else.

Then the winding and hand setting work is installed. This is a problem area for many watches, as far too many people over lubricate this section and the oil or grease runs everywhere.

We know turn the movement back over, install the seconds pinion and bridge, then put the pallet fork in place. It is at this point I will give the watch power by winding it via the crown. I can check the escapement functions again, just to make sure and then lubricate the pallet stones. It is very important NOT to lubricate the pallet pivots.

When lubricating the escapement, I choose to do it under the microscope so as to avoid any issues or mistakes. I lubricate the exit stone, and then move the pallet fork a few teeth around.

Note the quantity of oil applied each time. This is done several times to ensure even coverage.

I can install the balance, let the watch run for 24 hours and then check the timing. Letting the watch run allows the lubricant to settle and you will have more accurate timing results.

The watch is gaining time and severely out of beat.

I remove the balance and adjust the positioning of the spring to bring the beat error back into range. I can then adjust the timing.

Much better.

I can now clean the hands to bring back their shine, fit the new crystal and crown and then the watch will be tested for 48-72 hours to ensure accuracy.

So as you can see, there is more to a watch overhaul than timekeeping results. If I had over-oiled, left hairs in the movement, scratched all the bridges or screws, or even left the watch out of beat, you probably wouldn’t notice and for the first little while at least, there would be no signs to tell you that. You would probably tell or your friends about a great watchmaker you know.

I am not suggesting that you start opening all your watches to check (as that will void my warranty 😉 ) but ensuring you thrust the person doing your work is key. I receive watches on a daily basis that have been serviced by so called experts with decades of experience. The timekeeping is usually acceptable, but that is about it. If a watchmaker is willing to do ‘partial repairs’ by putting a splash of oil here, or a touch there, red flags should be raised. The question is this: Is your treasured watch getting the service it deserves?

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