Hi Everyone, I originally intended to post this in the owner built precision regulator thread that I started in the clock construction forum. However my life doesn’t seem to be settling down as much as I would like and I think this is too important to wait until I get to discuss it there. Also, this thread has more exposure. In 1982 I started full time construction of 5 precision regulator movements as I have pictured at the end of my first post in the above-mentioned thread. Tonight, because I could not get enough lighting into the assembled movement I pulled it apart to give you an idea of how the arbors looked before I tried to use WD-40 as a preservative. Here is the movement with front plate removed to show the placement of the arbors: I seldom take this down because all the tolerances are very close and with plates that are 5/16 inch thick the risk to the ruby and sapphire jewels is rather high. The white arrow points to a clear sapphire that disappears in the photo, the rubies are obvious: Here are the 3 arbors from the movement. Note the finish: This particular movement was to be a demonstration piece that I never intended to case. Because of this I used arbors that weren’t up to my standards. The other 4 arbors of each size were actually finished to a higher standard. All told, they all took about six weeks of full time work to make, including weekends. Before we moved from Wisconsin to Virginia in 1984, I was not able to finish everything so I removed all of the wheels and stored the arbors in a tin can covering them with WD-40. I figured that if any condensation got into the can, the water-displacing feature of WD-40 would keep moisture away from the polished steel surfaces. About once a month I would check the can and top off the WD-40 to keep everything submerged. In 1993 we moved across the country again, this time to Arizona. In 1997, after 13 years of having no trouble with this method of preservation, I was heartbroken to find that, since my last check, the surfaces of arbors had all been destroyed, making them all useless: Here is a close up of one of the escapement arbors where you can still se a little of the original surface on the right: Here are two closer views of the same arbor: What puzzles me are the deeply etched lines that run along the surface, more or less parallel with the shaft. When I discovered this I was working for the Physics & Astronomy department of a university and nobody I showed these to had any good explanation for what caused this. One person did however mention that he had heard that WD-40 will actually absorb moisture from the air. This is the closest I have come to finding an answer and I ‘m just passing the information on.