The early 1950s was like a change of season for the Hamilton Watch Company. The designs and traditions of the 1930s and 40s was giving way to a new era. Very soon new, Swiss-made movements would be introduced, including automatics. Less expensive materials would be adopted too, like rolled gold plated cases and stainless steel backs.
I wouldn't go as far as to say that Hamilton's standards were reduced. The fine traditions of Hamilton watch making did not go out like lamb with new standards coming in like a lion. Instead, a greater array of products and offerings were available, including at lower prices points to compete with the evolving watch industry, in general.
One of the hold outs for "traditional styling" was the 1951 Kirby. It was produced for three years. It has a strong family resemblance to several 1940s models. I think the dial is very Midas-like with two types of solid gold markers with gold numerals inside the chapter ring at 12, 3 and 9.
The Kirby is on the smaller side, like a 1940s watch. It was cased in 14K gold filled. By 1953 the overall design was the same however the movement inside switched from the 14/0 sized 19 jewel 982 to the 12/0 sized 19 jewel 753 movement. Technically, when that change occurred sometime in 1952, the case changed to the Kirby B to accommodate the differently shaped movement. So the movement inside helps to date the year the watch was made. The price was the same, regardless of the model year... almost $900 when adjusted for inflation.
My project watch arrived in good aesthetic condition but not running. I have to open it to see what movement is inside.
The case back is contoured from side to side and it's very evenly worn. The gold filled layer is worn through on the lower left of the photo below. I won't do too much polishing to the case.
The shape of the case opening and the name are good clues that this is the 14/0 version. If it was the 12/0 version it would say Kirby-B and the opening would be slightly wider and slightly shorter. The dial feel locations are different too so a Kirby dial won't fit a Kirby B - even though they look identical.
The 982 was highly damascened at this point in time. Even the 17 jewel 980 was too. It's a nice looking addition that only watchmaker's at the time would have admired. Based on the serial number on the barrel bridge, this is a 1951 model.
You never know why a movement won't run until you get to check it out closely. Using the tip of my tweezers I can see the balance swings freely and without a wobble. So the balance staff isn't broken. What I don't see though, is the pallet fork moving when the balance swings passed it. So there's either a pallet fork issue or a balance issue.
The balance is a very complicated part. It's the "heart" of the movement and it controls how the energy of the mainspring is released, tick by tick. It has several integral parts including the hairspring on one side, and the roller table on the other side. Installed within the roller table is a tiny precision lapped jewel called in impulse pin. This jewel is what engages the pallet fork, or vice versa. The energy from the mainspring goes through the train wheels and pushes on the pallet fork. When the balance moves the pallet fork, the energy releases and pushes the pallet fork, which in turn, pushes the balance again.
It's sort of like pushing a child on a swing set, you give them a shove, they swing out, swing back past you and then you shove them again, over and over, until all your energy is exhausted.
You may be able to see there is just an empty hole in the roller table of this balance. The impulse jewel is missing. Normally it's held in place with shellac.
There's already a white alloy "lifetime" mainspring installed in the barrel so the only thing I see that needs to be addressed is the balance.
I remove the balance from the balance cock. Now what?
There are LOT of ways to screw up from here. Some of my options include; replace the balance entirely, replace the roller table with one with a jewel, try to find the impulse jewel and then reinsert and glue it.
Option 1 is replace the movement but in order to do that another movement must be sacrificed. So that's really my last option. Option 3 is extremely challenging because the jewel is so tiny and getting the oddly shaped jewel to fit in the D-shaped hole, then glue it, is very time consuming. So I'll go with option 2 and attempt to replace the roller table.
Replacing the roller table is a part of changing the balance staff - another very challenging task. First you have to remove the hairspring without ruining it's shape or knocking it out of level. I'll have to put it on again so I mark the wheel with a sharpie to say where the hair spring stud should go. I also mark the wheel on the other side to indicate where the impulse jewel should point.
I have a donor balance with a messed up hairspring but a good roller table. I can steal this one and install it on my project balance. It's the exact same process, I just have to do it twice.
To get the hairspring off I use my green Bergeon oiler to slowly and carefully lift the hairspring up the balance staff until it comes free.
Now I can use my staking set to hold the balance by the roller table - this is very precise work, I don't want to break the pivots on the balance staff. You can see why I needed to remove the hairspring. It wouldn't fit in the tool.
With a special punch of the exact size needed, I can use a hammer to push the balance staff down and out of the roller table.
Voila. Now I do the same with the other balance to remove the damaged roller table.
Here's my good roller to install on the good balance.
Now I have to change my staking setup to two punches to support the balance staff. I install the roller table with the impulse pin pointing to the mark I added to the wheel so it goes back the way it originally was. I added a tiny amount of red locktite to keep the roller in place once I seat it. A punch on top with a couple of light blows from a small hammer will seat the table.
So far so good. One fascinating aspect of balance wheels is the mass of the balance is matched to the length of the hairspring. Swapping a hairspring from one balance to another is doable, but if the mass of the two wheels isn't the same, the beat rate of the resulting assembly could be way off. You might get lucky but the odds aren't in your favor.
At this point I can flip the balance over and reinstall the original hairspring using the same setup in. my staking set.
Now I place the collet on the balance staff with the stud pointing to the black mark I added to the wheel.
A few gentle taps with the hammer seats the collet on the staff. As you can imagine, there are countless ways to screw up this very precise task. I think I'm in good shape so far. Now I can clean the rest of the movement and the final test will be when I reinstall the balance.
Okay - everything is cleaned and dried. This can be a tricky movement to reassemble but time and patience will see me through.
Well looky here... I found the impulse jewel for option 3. Imagine trying to pick this up with tweezers and install it in an equally tiny hole without losing it a dozen times.
It's the moment of truth... the movement is assembled and wound up. Time to add the balance assembly
Success!!! The movement is ticking away with a good motion. Now to see if it's close to accurate.
Hurrah! The beat error is below my personal spec of 3.0ms. The amplitude didn't register yet but it was a healthy 250+ degrees. I could try to lower the beat error by removing the balance but that's risky business and I've made it this far without peril. I know when to call it a day - and it's been a day.
The glass crystal on this watch wasn't too bad so I just reinstalled it after cleaning the case. Paired with a fresh black leather strap, this little Kirby is ready for some more wrist time.
I'm glad I was able to save the balance - it took a bit of time but it's better than sacrificing another movement that could be used elsewhere.
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