Dial
The porcelain dial had actually been cleaned once or twice with a dish cleaner when this picture was taken; note, do not try this with a non-porcelain dial! The liquid dish cleaner took off some of the rust areas; however, diamantine, a very fine polishing compound, removed the rest. There are still some spots on the dial, but it looks a lot better. The first photo on my site and in this article show the cleaned dial.
Mainspring
The mainspring, broken at its center, was replaced.The mainspring stores and releases the power that drives the gear train.
When the key (stem in other watches)is wound, the coils of the mainspring wrap tightly around an arbor that is enclosed inside a barrel.
Be sure and wind your key wind watches slowly because there are not any gears to reduce the torque of the winding.
Upper Staff Pivot
The upper pivot was damaged. When replacing a staff, the hairspring and roller table are removed. The easiest way to remove a hairspring is by positioning a v-shaped lever under the hairspring collet and prying up. I used a Rex Roller Remover and a staking punch to take off the roller. The positions of the roller jewel and hairspring collet were noted on paper in relation to the balance rim. The balance screws helped with alignment of this location. This gives an approxiamate idea of the beat of the watch. The old staff was removed by cutting it out on a lathe.
When selecting a staff, it is a good idea to have at least two or three to choose from to find the best fit. Check the fit of pivots in the balance hole jewels. See how far the roller table goes down onto the staff. If it is too far away from the shoulder and the roller table is pressed down then it will split the roller table. The same is true for the hairspring collet. I had to reduce the diameter of the roller shoulder on the staff for this Rockford. I have had to re-pin hairsprings to new collets because they have been cracked by someone forcing them into place over a diameter that was too large; of course, the condition may be reversed with the staffs diameter too small. If the brass hairspring collet is too large for the staff then it may be tightened by using a cup-shapped concave staking punch that fits over all of collet. When the punch is tapped it causes the sides of the collet to close.
Roller Jewel
This roller jewel was broken off. Often enough, the shellac loosens with age and the roller jewel has to be re-shellaced. The part is heated in a holder to apply heat indirectly. The shellac is melted, the jewel is positioned upright before the shellac cools. The jewel may not lean as this will have an effect upon the action of the pallet fork. The height is important too. The roller jewel is selected based upon its fit in the pallet fork slot.
Pallet Fork
One pallet jewel was broken and the other loose. Notice that a pallet arbor pivot is broken too. The pallet has two jewels or stones: the "L" and "R" stones. They have different angles and are set to lock and unlock at certain depths upon the escape wheel. The escapement transfers the power from the mainspring to the regulating unit, changing the circular motion on the train wheels into the back-and-forth motion of the balance.
Pallet Pivot Fabrication
After searching for a pallet arbor, I made this pivot and the one above. There were three dimentions to cut on this pivot. A tiny hole was drilled in the pallet arbor. The finished pivot was turned to a snug fit and cemented with Loc-Tite for extra security.
Blued Screws
One screw was broken in this movement. Replacement screws were selected with correct threads and diameter, altered, then blued.
Conclusion
At the out set of this project, the desire was expressed that the watch would keep time to within five minutes a day. That expectation was exceeded. The Rockford timed at under a minute a day during its observation period. This is exceptional given all the work that had to be done to the watch.
Watch restoration may be unpredictable, but it is rewarding.
