I was going to just report about my experience so far with lubrication of the gears on my SP14 Moon Phase clock. But I decided it would be cool to start a Post about the subject in general to see what experience others are having. Maybe we can find an ideal lubricant. Which, I don't know, this one I used may be it. So if you would like to share, please post what lubricant you are using and what experience you have had with it. Here is mine.
When I was first starting up and breaking in my clock, I ran it dry (no escapement) to break it in with whatever weight I needed to make it free-run. After brushing some of the Synthetic Gun Oil (shown below) into the pinions using a small brush, while it was free-running, it really took off. And I found I could make it free-run on it's own with significantly less weight. Over the next day, I applied this lubricant, very thin film each time, three more times, mostly to the faster running gears, allowing a few hours in between each application. I honesty think this has helped my SP14 clock run well. Currently ticking along nicely since it was started, and keeping time very accurately.
My theory is that the microscopic Teflon particles, and other additives, suspended in the oil get embedded between the layer lines of the working gear surfaces, and over time and a few applications, builds up enough to fill in the voids and provide much smoother, less friction working surfaces. Doing it while the clock is free-running not only helps distribute the film evenly, but also serves to ram the suspended additive particles into the layer voids. My thinking in regards to using a PTFE based technology, compared to something like a grease, is that it is less "sticky" than a grease product.
Anyways, not sure if this is real or not, just a theory. But my clock does run with very little friction, at least for now. Only time will tell how this behaves in the long run.
Here is a link that has a description of the product. Show us your lubricant.
I use the very popular WD40, applying a very light layer on the axles: I spray a small amount on a cloth and take the axles to lubricate them.
The thing that in my opinion is fundamental is to cut the axles to the right size so that there is a play of at least one millimeter once the chassis is mounted and file the tips of the axles with a Dremel.
Another fundamental thing is to enlarge the holes in the gears.
In the end the entire gear train must practically "float in the air" reducing friction to a minimum.
On the pinions, as recommended by Steve, I sometimes applied a very light layer of lithium grease.
My experience is based on the following watches:
- SP5
- SP13 printed twice
- SP14 with the old gear design
All 4 watches work perfectly with just 2 kg of weight on the pulley!
The SP14 watch even without even a little grease on the gears!
All 4 clocks have a pendulum swing of 5 to 6 degrees, making them extremely reliable.