I’m talking oil. Specifically which oil, how much and EXACTLY where it needs to go.
After much dry stripping and reassembling of the 6498, it’s time to start oiling. First things first, oiling the shock settings that support either end of the balance staff.
To get the practice in without having to keep cleaning the watch, we use a plate with 20 incabloc settings mounted in it. After setting the jewels at the right height, the task is to apply a precise quantity of oil dead centre on the ruby end-cap and then mount the ruby into its setting. After a few practice runs under the tutor’s supervision, we have to implement our own quality control. Oil all 20 jewels perfectly and submit them for inspection. Any mistake on any one of the settings gets the plate dunked in alcohol so the whole lot has to go into the cleaning machine to be started again. Complete the whole plate successfully 5 times and you’re done! 100 jewels straight with no mistakes sure gets your eye in!
Then it’s on to servicing the whole movement. Stripping, cleaning, lubricating and reassembling the keyless work, train and escapement.
Repetition, repetition, repetition. I invested in a finer oiling needle than those supplied in our school toolkit and moved to working under a 30x microscope. Accurate placing is so much easier than trying with an eye glass in.
I’m getting better with practice but could still do with a little more finesse, especially on the escape wheel teeth. Pushing a ‘needle’ with a bead of oil on the tip into a watch movement and ensuring that oil only ends up in the intended place is an acquired skill. I need a few more goes yet.