So I wanted to post this since it's a little more unusual than the wear I've shown in most of the photos so far. Servicing a micro-brand diver with a Standard grade ETA 2824-2 inside. The watch was barely ticking when it came in, and my inspection showed that some oils had broken down so pretty normal stuff, but the thing that caught my eye was a large amount of brownish debris on the pallet stones:
So as I disassembled the movement I kept a close eye on that area, and found this:
This is not something that I see a lot, but I have seen it a few times. Wear happening at this extent between the fork horns of the pallet fork is unusual certainly. This is where the roller jewel (impulse pin) swings into and unlocks the escapement, and the fork pushes the balance - here is what the roller jewel area looked like:
Tried to get a good shot of the wear in the fork:
Decided that my usual microscope was not powerful enough, so pulled out the bigger one - you can see the wear in the area between the two arrows, and there is the same wear on the opposite side of the inner fork horn:
Over the years I have seen a number of watchmakers debate the cause of this wear, as it's very specific to this area. The sheer amount of debris seems to be more than the actual material that has been worn away from the pallet fork. The material looks quite rusty in colour, and for me the best explanation I can come up with is that there was possibly improper application of epilame to the pallet fork. Epilame is a treatment done to specific parts in the movement to prevent oils from creeping away from where they are placed, and typically only the actual jewels of the pallet fork are treated, so you keep the treatment away from this area of the fork. The application is done using a solvent carrier, and when it dries quickly the temperature of the parts drop rapidly, and condensation can form - my best guess is that happened here and it lead to a slight amount of rust forming in this spot, that in turn lead to this wear.
The roller jewel is fine, so a thorough cleaning of the movement and a replaced pallet fork will get this movement running again. But this is another illustration that when you see debris, it has to come from somewhere, so you must track down the source and check those parts carefully.
Cheers, Al
