Adjusting a Greasy 1918 Waltham 645 16s Pocket Watch to 6 Positions: On Motor Barrels and Motor Oil

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Although eBay is the wellspring from which grimy pocket watches flow, I fish in a few smaller rivers. A local, family-run coin shop gets a surprising number of broken and ugly watches that they’ll sell for a fair price. These days, when every pawn shop and antique mall thinks a 7-jewel Elgin in a gold-filled case is worth $175, finding a fair price in a brick-and-mortar store is no small feat.

I recently picked up this Waltham 645, a 16-size Model 1908 pocket watch. We haven’t done a Waltham yet on the blog, and this is a particularly nice model. It has 21 jewels, 2 of which are in a jeweled motor barrel. The balance swung and the watch would wind and set, so nothing seemed obviously wrong.

At first glance, it looked grimy but not unusually so.

The chip in the dial is typical for lever set watches and adds some period-correct character, I think.

But here was the first bad sign when I started to strip it down: greasy oil leaching out of the movement.

The back of the dial and the plate are covered with what looks like motor oil. It has the viscosity of the Mobil 1 0W-40 I put in my Saab. You hear about these acts of watchmaking malfeasance—someone thinks a watch “just needs some oil” and hoses it down with WD40 or silicon grease—but I haven’t seen it yet. Gross.

The whole watch was like this: everything from the hairspring to the wheels was coated in oil.

So it’s off to the cleaning machine. After a good scrubbing, the watch is bright and shiny. As always, the old blue steel mainspring was replaced with a white-alloy spring. This watch takes a 2227, if you’re curious.

After assembly, the watch started ticking nicely with huge amplitude in all positions. I demagnetized it for good luck and let it run for a couple days to settle in before measuring the rates.

Adjusting to Positions

After a watch has settled in, it’s time to adjust it to positions. Anyone can service a watch and get it to tick—getting it to be accurate is what the venerable craft of adjusting is all about.

Before fiddling with the watch, it’s a good idea to think of the good and bad omens so you can set realistic accuracy goals.

This watch has many good omens:

  • The watch has 21 jewels, including a jeweled motor barrel.
  • It was originally adjusted to 5 positions, so it was an excellent watch in its day.
  • This watch was made during one of Waltham’s best period for watches, before they got “asset stripped” through chronic under-investment.
  • The watch has handy features, such as a micrometer screw regulator and meantime screws.
  • The balance screws look pristine—no evidence of gouging, scraping, or hacking.

As for bad omens, we have only one: at one point, it had an owner foolish enough to douse it with motor oil.

All told, I think we can do good things here. We’ll aim for 5 positions, with no position more than 7 seconds from 0.

Measuring the Initial Rates

Off the bat, the watch wasn’t terrible. The amplitude was at least 280 degree in all the vertical positions and over 310 in the horizontal ones. The timing traces were stable, clean, and parallel—Waltham’s best watches were fine indeed.

Here’s what we were looking at.

The best news is that the dial up (DU) and dial down (DD) rates are basically the same. The first task of adjusting is getting the DU and DD positions aligned, and a million little things can cause them to vary.

The vertical rates are far apart, but some are faster and some are slower than the DU position. It should be easy to get all 6 positions to converge to zero.

Overall, the watch is running fast. I prefer that because the wheel’s poise can be improved by adding weight, which is easier and safer than removing weight.

Tightening the Rates

As we have described in the dynamic poising series and in some detailed posts, you start by finding the balance wheel’s heavy spot. To do this, run it at low amplitude and find the fastest position.

When run at 140 degrees of amplitude, the watch was fastest in this position.

This means that the heavy spot is directly below the balance staff

Awkwardly, the heavy spot is between two screws. In these cases, you can place small weights on the screws on each side. (Alternately, sometimes it makes sense to place a heavy weight on one of them, thus shifting the heavy spot to a spot with timing screws.)

Dynamic poising is a rinse-and-repeat process: find the heavy spot, make an adjustment, observe the rates, and then do it again.

It took 4 rounds of adjusting to get this watch tight. Only timing washers were used, so no weight was removed. The heavy spot was always in an awkward spot, such as between screws or at a mean-time screw. But the vexation paid off—all’s well that ends well.

Here are the final rates:

This is a phenomenal result, and the watch deserves much of the credit. It is much easier to adjust a fine watch than a crappy one, and this Waltham was designed to keep railroad time.

The Case and Dial

So, with the movement ticking along nicely, it was time to confront the oil-soaked dial and case.

I started by running the dial, case, and crystal through the cleaning machine—not my usual practice, but the cleaning solvents removed the caked grease. The gold-filled case then got scrubbed with a soapy toothbrush and got a light polishing with Menzerna Yellow, a compound that gives a nice shine to gold without removing material.

This watch came with a plastic crystal. These are a little tacky on vintage railroad watches, but I’ll keep it for now. I prefer plastic crystals on watches I carry every day—they are rugged and easy to buff clean—so I buffed the crystal and will see how I like it after a few days.

Don’t tell my Illinois Bunn Special, but I think this might be my nicest pocket watch. It’s quite a sight.

Wrapping Up

This sucker looked nasty, but beneath the grime was an incredible watch. With a simple cleaning and some standard, no-frills dynamic poising, it was brought back to the railroad-quality time it kept when it left the factory.