When you fish for pocket watches in the murky waters of eBay, estate sales, and pawn shops, you’ll find some seriously mistreated watches. A certain kind of person, when finding an old watch that won’t tick, thinks, “Huh, probably just needs some oil” and hoses down the movement with WD40. That, of course, never works, and then the miscreant has a greasy, smelly watch.
Here’s a victim of such shenanigans: a greasy Illinois Grade 114, a 16-size (Model 1) 15-jewel watch. It’s likely from 1892, according to Pocket Watch Database, making it one of the oldest watches we’ve seen on this blog.
That green ring is thick, gloppy oil that collected under the bezel.
Check out the globs of oil on the mainspring barrel and plates. WD 40 is meant to displace water and prevent rust, so when it evaporates it leaves a sticky residue like this.
A shiny film covered the balance wheel and hairspring.
Here’s an odd thing: the barrel bridge was popped off the movement plate. I think someone started to unscrew the movement, fiddled with it, and then tried to fit it back together but couldn’t get the bridge to sit flush. This model has concealed winding works, and the winding gears under the dial won’t easily mesh together if you randomly mess with it.
The case is in bad shape, as old hunting cases tend to be. The hinge is badly broken.
The crystal is missing, too. These fragile glass crystals, along with the case hinge, are common flaws in hunting-cased pocket watches. Amazingly, the hands are in respectable shape, albeit a bit bent, and accounted for. They often get lost when the crystal is missing.
As a final indignity, the bow has been replaced with a basic steel or nickel piece that doesn’t match the gold-filled case.
Cleaning & Preparing the Movement
The movement was nasty, but it cleaned up well. I keep some old cleaning solutions on hand for the first cycle of greasy watches like this one. Once it was cleaned up, the movement’s only flaw was a tired, set mainspring, which is easy to replace.
The watch roared back to life after assembly. After centering the regulator arm and turning the mean-time screws inward a full turn, here are the dial-up (DU) rates.
Not too bad for a mistreated watch from 1892! Illinois Watch Company really made great watches.
As an aside, the amplitude readings on a Timegrapher presume a specified lift angle. For modern watches, you can look up the lift angles on spec sheets. The default in the Timegrapher is 52 degrees, which fits many wristwatch calibers but often needs to be tweaked to somewhere between 50 and 54 degrees.
But for these really old pocket watches, with not-quite-interchangeable parts and adjustable banking pins, it’s hard to pin down a lift angle that applies to the whole model. I think 52 degrees is probably close enough for this specific movement. Watching the movement of the balance wheel’s arms and detecting where they stop swinging—the original old-school way to measure amplitude—suggests that the timing machine’s amplitude estimate is probably about right and at least 280 degrees dial up.
You might have noticed that the beat error is fairly high, around 5 ms. For modern movements with moveable stud carriers, reducing the beat error is easy. For these older watches, however, you have to adjust the hairspring collet. This video gives a nice overview of how to do it.
When it comes to messing with the hairsprings of watches from the 1800s, discretion is the better part of valor, so a beat error under 3 ms would be fine with me.
This watch, like many watches that have had balance staffs replaced over the decades, has an off-centered roller jewel. Some movements, like the Hamilton 980/982 family, were designed this way; others ended up with way after a repair. This jewel probably should be at a right angle to the balance arm, but I don’t know enough about this family of Illinois movements to be sure.
After a couple tries, the beat error ended up around 1.5 ms, which is definitely good enough.
I let the watch run for a day, changing its position every now and then, so the mainspring and oils can bed in and settle. Here are the rates in all 6 positions at full wind: they’re pretty good. (Remember that pendant left and right refer to the dial side, but we’re looking at the watch from the movement side.) The dial-up and dial-down rates are similar, and none of the positions is way out there.
So the watch seems solid already, but we can improve on the rates by adjusting it.
Adjusting the Movement with Dynamic Poising
The basic notion of dynamic poising, as we’ve explained throughout this blog, is that you can find the heavy spot on a balance wheel by running the watch at low amplitude, around 140 degree in the vertical positions. Running at low amplitude exaggerates the effects of poise errors and thus makes them much easier to spot.
Here’s what this watch looks like at around 140 degrees.
The red positions are the fastest, at around +80 seconds a day. The PD and PR-diagonal value were basically the same, which happens sometimes. This means that the heavy spot is in between them, which I checked and confirmed but didn’t put on the picture. This means that the heaviest spot is directly under the balance staff when the watch is in this position.
So, what is exactly beneath the balance staff? Interestingly enough, there’s a rough looking screw with a huge timing washer under it at that spot, circled in red.
The screw looks bad. It has been filed on the face at an angle and has a ragged edge, a sign of poor filing. For screws with slots, it’s better to undercut the screw or deepen the slot, two unobtrusive methods.
I call these “Oh crap!” screws. Whenever you see a screw missing a lot of weight on top of a huge timing washer that adds weight, you get the impression that someone, way back when, made a mistake when working on the watch. They filed off too much weight, said “Oh crap!”, and put a timing washer on to correct their error.
Before adjusting, it’s best to take stock of what you’re looking at and what kinds of accuracy goals are realistic. For this watch, the good omens are many:
- This watch was designed to be a high-quality, high accuracy watch in its time.
- The overall condition of the watch is pretty good.
- The rates are stable instead of wavy.
But there are some bad omens:
- The gear train has a lot of small flaws that are common in old pocket watches. Some of the gear teeth are a bit rough, many of the pinion leaves have uneven wear, a couple wheels seem slightly out of flat, and the pivot holding the seconds hand is very slightly bent.
- While not exactly fatal flaws, taken together, these will degrade the consistency of the watch’s timekeeping. When you watch the rates for minutes on end, there’s a slow, long-wave periodicity to the traces. This watch will never be a “dead accurate” watch.
Overall, I think going for a “straight limit” of 10 seconds (no rate more than 10 seconds from zero in any direction) seems reasonable.
If you’re new to dynamic poising, you should read your way through the how-to series to learn more about it. The dial-up (DU) and dial-down (DD) positions are already close, so the first step is checked off.
Our next goal is to align the four vertical rates—pendant up, right, down, and left (PU, PR, PD, and PL)—to be more similar. And we want to align them in a way that brings them closer to the DU and DD rates, so that all 6 start to converge.
If a watch is running a bit slow DU, then removing weight from the heavy spot will do two desirable things:
- It improves the balance wheel’s poise, thus aligning the 4 vertical rates
- It speeds up the watch, bringing all 6 rates closer to zero
Remember, if the watch runs slow DU, remove weight; if it runs fast DU, add weight. (And, of course, if you want to avoid removing weight, you can make the watch run fast DU via mean-time screws.)
To remove weight, I used a balance screw file and a screw slot file. This screw was already mangled, so filing it would both improve the balance wheel’s poise and improve the screw’s appearance by smoothing its ragged edge.
It took two rounds of very slightly filing the screw and then testing the rates, and here’s where we ended up—notably better than before, but not the ultra-close rates you can achieve in modern watches or high-grade vintage watches.
All the rates are under plus/minus 10 seconds, on average. Because the watch is slightly wavy over long intervals, these rates are basically averages and have a margin of around plus/minus 4 seconds, so they aren’t as great as they look. It’s just the way it is when the gear train has accumulated a lot of small flaws.
This movement is a good example of how watch adjusting needn’t be a long, drawn-out drama. It is sometimes (ahem, 12-size Hamiltons), but most of the time adjusting is making a solid watch appreciably better by spending 15 minutes to improve its poise.
Wrapping Up
Overall, I’m pretty happy with how this movement turned out. This watch will keep excellent time for the dapper gent who carries this watch to work. But for that to happen, first we need to do something about that broken hunter case, the topic of Part 2.