My stash of watches to fix is slowly shrinking, and I’m reaching some interesting and complicated cases. Here’s the current patient: a big, chunky Illinois pocket watch. This is an old one: an 18-size, Model 2 (Grade I.W.C.) from around 1887. It is relatively low spec, with 7 jewels and a nickel case.

I don’t remember where I picked this one up—probably a coin shop or pawn shop around 5 years ago. Cosmetically, this pocket watch presents nicely. Aside from being grimy, the dial, hands, and case are in good condition and will clean up well.

This is a lever-set watch from the transitional period, so the mainspring can be wound with either a key or with the case stem.

A Few Small Repairs

But many watchmaking shenanigans are concealed beneath the surface. Like most old pocket watches, this one had a list of common flaws of the “dropped and put in a drawer” variety: the balance staff was broken, and the roller jewel had broken off.

Aside from that, there were a few quirks. One of the upper jewel screws had snapped off in the hole.

You can remove these a couple ways, but if you don’t have micro screw extractors handy, soaking in alum works wonders for dissolving broken screws. After removing all the other parts (other screw, regulator arm, jewels, etc.), soak the part in hot water mixed with alum, found in the local grocery store. I used around 1/2 teaspoon of alum in a 1/2 cup of hot water. Keep it hot, occasionally stir, and every few hours scrape away the black gunk that forms on the exposed steel surface.

After around 12 hours, the screw had dissolved, leaving a clean hole behind.

Speaking of the regulator, the pins were broken and malformed. One pin snapped off, and the other looks like it has been filed or shaved. I’ll leave the intact one alone and replace the other pin.

Replacing these pins is easy and something I should probably do a post on sometime.

Modify the Part to Fit the Watch, Not Vice-Versa

But those were just the ordinary flaws—this Illinois watch had clearly been in the hands of someone who was cheap or lazy. An old dictum in watchmaking is “modify the part to fit the watch, not the watch to fit the part.” It might be faster or more convenient to adapt the movement to the parts on hand, but it’s a poor approach and others will pay the price down the road.

Here’s one example. The side of the mainspring barrel was chiseled to create a stop edge, much like the barrels for Swiss wristwatches.

And here’s the mainspring that was installed. You can see how someone chiseled the stop edge and then riveted a tongue end onto the mainspring to catch it.

The only reason to do such a thing is to avoid the time and expense of acquiring the proper mainspring. Illinois watches have never been obscure, and the 18s Model 2 mainsprings have never been rare.

To replace it, I used a Generale Ressorts mainspring: GR7104T, which fits this model and has the appropriate T-brace end secured by the holes in the barrel and cap.

This watch probably had endshake problems in the past. There were signs of old “pig’s ear” dimples under balance bridge that had been filed off, and there was a weird green tape under the bridge.

The balance staff was broken but seemed too short. There are many flavors of 18s Illinois balance staffs, and I’m not positive that this was a correct one.

One way that they corrected large endshake issues back in the day was to modify the jewel depth. For this watch, the lower balance jewels are secured in the potence, the “cup” suspended beneath the top plate. The jewels are seated on a flange. Someone reamed the flange to adjust the jewel depth, bringing them much closer to the wheel than they normally would be.

I broke a cardinal rule of blogging—always take pictures—but bad pictures are probably “on brand” for this blog. Anyway, here’s an example potence from a much later 18s Illinois watch to illustrate the basic idea. Notice how the jewels sit against a flange. By reaming the flange the jewels can be moved upward. For the current watch, the depth was adjusted too much. It will fit the runty broken staff that was installed, but it won’t fit the proper balance staff, which is longer.

This is a curious situation and a good example of the inanity of modifying a watch to fit a part. Modifying the potence saved some old-timer the hassle and expense of buying a new balance staff, but it caused headaches down the road for people who want to get it done the right way.

What to do? There are a few options:

• Replace the potence from a similar donor watch. I’d prefer not to do this. For these old, elegant watches—even humble 7-jewel ones—keeping the original parts is important for collectors.
• Create a circular spacer for the potence, essentially a brass washer that restores the jewels to their proper depth. This can be done with flat shim brass stock or with brass tubing. I prefer this option but I don’t have any suitable material handy and will have to order some.
• In the meantime, we’ll do the third option: create a floating, flat spacer for the balance bridge. This option will allow me to finish repairing and adjusting the watch while I wait for the brass stock to arrive. Creating a flat spacer will also show me how thick the eventual brass spacer needs to be.

Here’s a humble spacer from inert, archival plastic. It is fully flat, so the bridge doesn’t tilt and the staff remains upright to the jewels. A flaw of the old-time “chisel dimples into the bridges” approach—aside from the obvious damage to the surfaces—is that it tilts the bridge at an angle. The same goes for bending the balance bridge, another common fix. A large-surface, flat spacer that surrounds the screw hole will maintain uprightness and suffice until I can create a brass potence spacer.

Adjusting the Movement

As a final step before adjusting, I spent some quality time with fine tweezers and the hairspring to get it centered. I find it easier to do this by removing the hairspring and installing it in the balance bridge. These old Illinois watches have flat hairsprings, not overcoils, and getting them centered is key to good positional timing.

After all the repair drama, we had a watch that was ticking away well. The amplitude was pretty good (the lift angle was around 51 degrees on this movement), and the rates were reasonably clean and stable for a 7-jewel watch from the 1880s.

After demagnetizing and a couple days left to run, here are the rates in all 6 positions. You should think of each number as having +/- 5 seconds around it. The rates are pretty stable in the short run (30-90 seconds) but show the usual wavy variance over the course of several minutes.

I think I may have benefitted from some watchmaking karma here. These are pretty good, especially for a watch of this age and grade. The three main pocket watch positions—dial up, dial down, and pendant up—are pretty close, and the rest are reasonable.

I have been working on “knowing when to quit,” and I think this watch is fine as it is. I’ll nudge the regulator to be near-zero dial up and call it a day.

Wrapping Up

After polishing the nickel case and cleaning the enamel dial, we were in business. I kept the big, chunky crystal, scratches and all, because it suits the case and the watch’s rough life.

This is a cool watch, without a doubt.

This watch illustrates a point we’ve made before about 7-jewel watches. Low-grade watches aren’t inherently poor, and many will keep great time, but they tend to end up in the hands of cheap owners, marginal watchmakers, and beginning hobbyists looking for a cheap watch to practice on. People take much greater care of finer timepieces, so high-grade watches are less likely to have a litany of weird flaws and botched repairs.