Basic watchmaking tips - Oiling part 4 (the escapement)

This is another installment in a series of watchmaking tips – previous threads can be found here:

https://omegaforums.net/threads/basic-watchmaking-tips-cleaning.56365/

https://omegaforums.net/threads/basic-watchmaking-tips-oiling-part-1.62310

https://omegaforums.net/threads/basic-watchmaking-tips-oiling-part-2-the-mainspring-barrel.71246/

https://omegaforums.net/threads/basic-watchmaking-tips-oiling-part-3-the-wheel-train.84482/

https://omegaforums.net/threads/basic-watchmaking-tips-spotting-wear.81025/

In this installment, I’ll go over the lubrication of the Swiss lever escapement. Based on the number of PM’s I’ve received asking for a post on this subject, many from people who appeared to have just joined to send me that PM, I’m guessing this is something that many new and amateur watchmakers will be interested in. Based on what I see in watches coming into my shop, it’s also something that a lot of people (even watchmakers) appear to struggle with.

So the escapement needs lubrication between the impulse face of the pallet fork jewels, and the heel of escape wheel teeth. There is sliding friction between these two parts, and although the watch will run without any lubrication there, typically the balance amplitude would be very low. Before we get to application of the lubrication, there’s a few other things I wanted to cover.

When I get a watch in for service, as I’m taking it apart I pay attention to the pallet fork stones to see how the teeth of the escape wheel line up with the stone. Depending on how well the watch was lubricated to start with, you may be able to see a path that the escape wheel teeth made through the lubrication, or through the dried residue in this case:



You can see here that the escape wheel teeth have made a very clear line, and it’s right down the middle of the thickness of the pallet fork jewel. The reason I check this is that I often encounter watches where the escape wheel teeth and jewel are not lined up properly at all. Omega has acknowledged to me that this is a known problem in some calibers, so for example on Cal. 1861/1863 I always check this, and often I have to correct it. I’ve seen some where the misalignment was so extreme that only half of the escape wheel teeth were contacting the pallet fork jewel, and as a result the lubrication applied was being drawn off the impulse face and onto the side of the jewel, where it doesn’t do any good.

So if I can’t see how well the parts are aligned as I’m taking the watch apart, I will assemble those parts together after cleaning and check the alignment:



And often I have to shift the upper and lower escape wheel jewels using the Horia jewelling tool, to bring them in better alignment:



Here’s an example of a watch where the escape wheel is riding close to the edge of the jewel:



After adjustments were made:



So once all that’s done and I’m assembling the movement, I treat both the escape wheel and the pallet fork jewels with something called epilame – also known as Fix-O-Drop (Moebius 8981). This substance is used on certain parts to create a surface treatment that prevents oil from spreading. Many applications in life where oil is used, for example in a gearbox, the goal is to get the oil everywhere inside that gearbox, so you want it to spread all over the place. But inside a watch oil is placed in very specific locations, and it needs to stay where it’s placed, so we don’t want is spreading everywhere. This epilame surface treatment will keep oil from spreading, so if I place a drop of oil on an untreated surface, it will spread. But with this treatment on the surface, it will bead up like water on a freshly waxed car.

So to illustrate this I’ve applied some oil to a cleaned glass surface in 2 locations. It’s roughly the same amount of oil, but the drop on the left was on an area that is untreated, and you can see that the oil has spread out – this is only a minute or so after I applied the oil. In contrast the drop on the right was placed on a spot that was treated with epilame, and you can see how the oil beads up and doesn’t spread:



To treat the escape wheel, I use a small plastic basket, and the wheel is placed in the basket after it’s cleaned and inspected:



The basket is then closed, and placed inside a bottle that has the solution inside, and the neck of the bottle allows the basket to be submerged when the bottle is inverted:



After just a few seconds in the solution, the basket is removed and quickly dried. The epilame solution is very volatile and the solvent evaporates very quickly, and this rapid evaporation leads to a temperature drop and can cause condensation to form on the steel parts, and possibly rust, so drying it fast using heat is a must. I push the pallet fork horn down into the pith wood as well. I then use a syringe filled with the epilame solution to apply it only to the entrance and exit pallet fork jewels, and not the remainder of the fork:



The reason only the jewels are treated is that the coating can be slightly abrasive, and if it gets into the fork horn it can cause problems like wear from the impulse jewel:



At least this is the best explanation that I have seen the watchmaking community come up with for the type of wear seen above, and in the photos below:







Again the jewels are dried using heat, so that any stray solution that gets on the steel parts does not cause any condensation and corrosion to form. Note that at the factory, the movements are often treated with epilame more widely than I’m showing here, so in many cases the entire movement with the exception of specific parts, is treated with epilame.

The epilame treatment can last 3 or 4 normal washing cycles, so it is not automatically removed when the movement is cleaned, however I always treat the escapement parts again because as part of the cleaning I roll the escape wheel teeth through pith wood, and push the pallet fork jewels into pith wood also to ensure they are very clean.

Once the parts are treated, they are placed into the watch, and the watch is assembled and lubricated, with the exception of the escapement. The watch is left to run with the escapement dry for a period of time – typically not less than 15 minutes. Then the balance assembly is removed, and you can oil the escapement.

There are different ways of doing this, so in addition to what I show here, I know some people oil by letting the watch run, and sticking an oiler through the dial side of the movement, letting the escape wheel teeth run through the drop of oil on the oiler. Personally I’m not a fan of this method as it doesn’t afford the amount of control over the oil applied that the method I use does. Some people will stop the movement and apply oil to the escape wheel teeth, but I prefer to apply it to the impulse face of the exit jewels on the pallet fork.

So before we talk about how to apply the lubrication, we should talk about the lubrication itself. Because of the start/stop nature of the escapement, regular oil applied here would tend to get flung off the escapement, so you end up with oil that is where it shouldn’t be, and not a lot of oil where it should be. For this reason the “standard” lubrication for the escapement is Moebius 9415. Now there was a time when there was another lubricant that was supposed to be for “low beat” watches, and that was Moebius 941. The 9415 was supposed to be for “high beat” watches only, but if you look at any modern tech guide for a low beat watch, say an ETA 6497-1 that beats at 18,000 A/hr, you will see that the 9514 is called out, like so (taken from the tech guide for the 6497-1):



The 9415 appears more as a thin grease than an oil, and in fact it’s a grease that has thixotropic qualities. So when it’s not under load it is viscous (thick) but when under the load/pressure of the sliding friction of the escape wheel teeth coming across the impulse plane of the pallet fork jewel, it becomes liquid momentarily, before returning to that thicker state immediately after. This property helps keep the escapement lubricated, and the 9415 staying where it belongs.

Okay so how should the oil be applied? Using your finest oiler, take a small drop and place it in the middle of the path that the escape wheel tooth will take across the impulse plane of the jewel:



Here’s an example with a drop of lubrication applied:



You can see I’ve added a drop of oil at the back of that surface, and this is probably the maximum I would use on this particular watch. The drop can be smaller, and it’s always easier to add more than to take away when you add too much, so going easy here is a good idea. Once this drop has been applied, I use my bronze tweezers to move the pallet fork back and forth, slowly across the jewel and through the drop of oil. I keep cycling the pallet fork back and forth (slowly) until the drop of oil has been taken away by the teeth. I then apply another small drop, and repeat. I then apply a third drop, and that will typically take me one full revolution of the wheel by the time it’s used up. Again if you want to start on the conservative side, you can just apply the drops twice for one revolution to start with, and after the checks I’ll describe you can add more if needed.

So once you have gone around the escape wheel teeth once, you should have oil on most of the teeth, but it won’t be evenly spread out, so the next step I take is to keep using my tweezers and run the escape wheel around at least a few revolutions. I personally count the spokes of the escape wheel as a move the pallet fork back and forth, and when I count 40 spokes gone by, I know the oil will certainly be spread out evenly by that point. you could probably do it less (my watchmaking instructor used to say at least 4 revolutions) but this is a habit I’ve developed over the years and I stick with 10 complete revolutions – 4 spokes on the escape wheel usually.

So now we need to check the amount. I’ll mention the way I was taught first, which is a little less clear unless you are sitting in a classroom seeing it demonstrated first hand. I was taught that as you move the pallet fork, and the escape wheel starts to come across the impulse surface of the pallet fork jewel, you will see a small ball or wedge of oil form in the angle between the tooth and the jewel. If that forms when the leading edge of the tooth is about 1/2 way across the surface of the jewel, that’s is about the right amount of oil. If it forms earlier than that, it’s probably too much, and if it only forms very late as it moves across, that’s probably too little.

Omega defines this in a more specific way, so they recommend that when you are cycling the pallet fork back and forth, you move it so that the tooth of the escape wheel goes just beyond the end of the jewel, then you stop and back it up to a point that is 3/4 of the way across the impulse surface. When it is in that spot, the drop of oil formed between the escape wheel tooth and the jewel should cover 1/2 to 3/4 of the length of the escape wheel tooth.

Since that’s probably as clear as mud, I wanted an example to show you, and I’ve used a special movement holder used for oiling Cal. 2500 co-axial escapements to rotate the balance on a Cal. 1120 and take some photos and video of this – here’s the holder:



Note that because this holder has the dial side of the movement facing up, the photos an video of the exit stone will have a different orientation than they did in previous photos. Here is a photo that shows what the rather wordy description above means:



So when you can see that the tooth is about 3/4 of the way across the jewel, and the oil under the tooth is 1/2 to 3/4 of the length of the tooth. Here is a video showing the checking procedure, again using that special holder so it’s a different orientation:


So this is all the oil you need here, and really controlling this amount is important. If you apply too much, I can cause low amplitude, and in some cases cause the oil to spill off the impulse surface and eventually it will be drawn away from where it belongs. Although I could show you countless examples of bad escapement oiling, I’ll just show a few.

In this example the oil is simply far too much:



This one has oil going way up the escape wheel teeth – enough oil on this one tooth to oil a few escapements:



Oil here isn’t helping the watch run better:



And in this one it’s also too much, but you can see oil has migrated to the side of the pallet fork jewel on this one:



And this one:



And this one:



Some days I just shake my head:



And you can see here that this watchmaker took photos of the oiling, and it’s excessive to say the least:



I could go on, but I think this illustrates that this is often a task that is not done well.

So I hope this gives you a better idea of what is involved in oiling an escapement, and what Omega considers to be the right amount of oil.

As always if you have any questions, please ask.

Cheers, Al

Most excellent post and pictures. Thanks Al.
I have a question about the 9415 lubrication. Since it is a grease and not an oil, is epilame important to keep the lubricant from migrating away from the initial location? It really doesn't flow like an oil.

I use epilame on every watch, and you will find most watchmakers with any sort of modern training will do so also - it is the current watchmaking standard. Omega does give instructions for oiling the escapement when not using epilame, and it requires a lesser amount of 9415 is used. So the image and video above that show the drop being between 1/2 and 3/4 of the length of the escape wheel tooth would be reduced to 1/3 the length of the tooth max.

Although the 9415 is more viscous than say 9010, that doesn't mean it will stay put on it's own. Since the lubrication will dry out over time, having more there is better than having less - I don't mean flood the escapement with oil, but the job will last longer and be more reliable if you use epilame, as that allows more oil to be used in the escapement without it migrating away.

Keep in mind that the application of such surface treatments is not new by any means. While the modern epilame solutions are a fluoropolyester in a carrier solvent of perfluorohexane (actually I think the solvent changed recently to something more environmentally friendly), in the past many watchmakers used cleaning machines that had a chamber of stearic acid, and parts would be held in the chamber to create the same kind of barrier film that the modern epilame solutions create.

There's no doubt that epilame is expensive, and I am assuming that is what may be driving your question. A 100 ml bottle is around $175 Canadian, and given that the solution in the jar is changed frequently, this is an ongoing cost that can add up. In my view something that you should not do without.

Cheers, Al

It depends on how much excess is present. If it you put too large a drop on the jewel and haven't run any teeth through that drop yet, you can clean off your oiler and use a clean oiler to pick up some of the drop. If you have oil where it doesn't belong, you take it apart and run it through the cleaning machine again.

I use the smallest of the Bergeon ergonomic oilers, so either the red or black rings on the handle, as they are both the same size.

It does take some practice to get the hang of doing this, and it’s important to pick up a smaller drop of oil on the oiler to start with. Easier to add more if needed than to take away oil.

Cheers, Al

Thanks - I'm glad you enjoyed it. I do not have a tutorial on lubricating the co-axial escapement, and it's unlikely that I will produce one. The servicing of co-axials requires specific tools that as far as I know only Omega sells to authorized watchmakers, and if you are authorized you have already taken Omega's training. This isn't something, IMO, that people who haven't had training directly from Omega and have access to the correct tools should be doing on their own, although I do know that many watchmakers who don't have the training or equipment "wing it"...

Cheers, Al

My watchmaker told me that he took that training, and then decided he would try to avoid servicing co-axial movements as much as possible. 😉

Of the 5 watchmakers in the course I took in NJ, essentially only myself and one other guy indicated that they planned to actually service these once the training was done. Most of the guys there worked for stores (they didn't work in their own shops) and said when a co-axial came in, they would just have the store send it to Omega for service. That way the store can take their cut off the top and not have the hassle of servicing these movements.

The course included servicing a Cal. 2500 Aqua Terra, and an SMP chronograph with a Cal. 3313, so we were supposed to complete 2 watches in their entirety. Even though we obviously had time just listening to lectures, had to wait for the instructor to check a various stages of the service before you could move on, spent part of one day on a service center tour, and a 1/2 of one day in the refinishing department, it was still plenty of time to service two watches. I had never done the 3313 before and I had then all done (including complete service of the movement, timing, mounting dial, hands, casing, etc.) with a full 1/2 day to spare on Friday afternoon. I'm quite sure the one guy who spent the entire 5 days just trying to lubricate the Cal. 2500 escapement properly just once, wasn't going to be working on these after it was over.

When I was servicing them very regularly, the additional time for a 2 level co-axial wasn't big - maybe an extra 15 minutes for servicing a 2500 on top of what an 1120 would have taken me. But it took me some time to get that quick, and initially it was a big time penalty to service a co-axial. The three level co-axials will ne less time, since there are only 10 lubrication points on that escapement, compared to 30 on the 2 level design...

There are a few steps involved in doing a routine service that I enjoy less than other steps, and I'd have to say lubricating the co-axial is up there with the things I like doing the least.

Cheers, Al

Mr.Daniels must be spinning in his grave!

This is similar to what my watchmaker said. He gave me the impression that it was a finicky process ... my word, not his.

It is. The drop of oil that you have to apply to the co-axial teeth is by far the smallest drop of oil I've had to apply in any watchmaking situation. The only way to do this effectively is under 50X magnification:



Apply too little and the escapement will get chewed up. Apply too much and it will wick away from where it's supposed to be, and the escapement will chew itself up...

The key is knowing that you have it done right. If you run a traditional lever escapement dry, it will be completely obvious on the timing machine that something is wrong. On a co-axial, you can run the escapement dry, oil it properly, or oil it too much, and it will all look fine on the timing machine. This characteristic unfortunately gives some of the watchmakers who "wing it" a false sense that they are doing things right, when they really aren't.

This is why I always suggest that if you have a co-axial, you either send it to Omega, or only use a watchmaker who has the training and equipment from Omega.

Cheers, Al

How to Help Oil a 2500D Coaxial Wheel?

Probably best if you use Google translate and include a photograph if you can.