| REPAIRS AND WHAT THEY INCLUDE |
There are two broad categories of repairs, Partial Repairs and Complete Repairs, or Cleaning & Overhaul).
The Complete Repair, or Cleaning & Overhaul, is a repair of the clock's MOVEMENT, or "works," that is, the
mechanism of the clock. The movement consists of two brass plates and all the gears, levers and other parts between,
and on, those plates. The overhaul also sometimes includes repairs to the pendulum, chimes or other parts.
On occasion, you may want to send me a clock for a partial repair, for example, an old and high grade clock or an
especially stubborn problem. But, on the whole, shipping clocks to me for partial repairs is not a satisfying solution for
the customer. In a partial repair, of course, I can only guarantee the specific work I have done, and not the overall
running and operation of the clock. To pay for a repair plus shipping, then have something else go wrong with the clock
just doesn't make sense. In addition, by the time a clock needs repair work, it usually needs a cleaning, rebushing, and
possibly other work. For these reasons, I strongly discourage sending clocks for partial work rather than for a "complete
repair", that is, a cleaning and overhaul.
The Complete Repair, or Cleaning & Overhaul, is a repair of the clock's MOVEMENT, or "works," that is, the
mechanism of the clock. The movement consists of two brass plates and all the gears, levers and other parts between,
and on, those plates. The overhaul also sometimes includes repairs to the pendulum, chimes or other parts.
On occasion, you may want to send me a clock for a partial repair, for example, an old and high grade clock or an
especially stubborn problem. But, on the whole, shipping clocks to me for partial repairs is not a satisfying solution for
the customer. In a partial repair, of course, I can only guarantee the specific work I have done, and not the overall
running and operation of the clock. To pay for a repair plus shipping, then have something else go wrong with the clock
just doesn't make sense. In addition, by the time a clock needs repair work, it usually needs a cleaning, rebushing, and
possibly other work. For these reasons, I strongly discourage sending clocks for partial work rather than for a "complete
repair", that is, a cleaning and overhaul.
| THE OVERHAUL START TO FINISH |
1) DIAGNOSIS: Before disassembling the clock I observe it in its case, start the
pendulum swinging, and cycle the hands through the strike points. I look for any
installation-related problems, such as pendulums scraping against the case back,
etc. I make note of what works and what doesn't.
Then I remove the movement from the clock and do the same thing all over again,
looking for problems inside the movement, and generally observing the amount of
wear in the bushings, the condition of the gear teeth, the "end shake" and "side
shake" (tolerances) of the arbors, and other critical problems
pendulum swinging, and cycle the hands through the strike points. I look for any
installation-related problems, such as pendulums scraping against the case back,
etc. I make note of what works and what doesn't.
Then I remove the movement from the clock and do the same thing all over again,
looking for problems inside the movement, and generally observing the amount of
wear in the bushings, the condition of the gear teeth, the "end shake" and "side
shake" (tolerances) of the arbors, and other critical problems
2) DISASSEMBLY: I disassemble the entire movement by separating the two main
plates, removing all the gears and other parts, such as levers, cams, hammers, etc.,
noting problems as I go.
plates, removing all the gears and other parts, such as levers, cams, hammers, etc.,
noting problems as I go.
3) All these parts are then cleaned by both machine and by hand. The cleaning
machine is fine for removing general grime and returning a bright polish to the
plates and gears. But only hand cleaning removes hardened dirt and oil INSIDE the
pivot holes. Over the years, old oil dries to a varnish-like hardness inside the pivot
holes , and must be removed by "pegging out" the holes, that is, turning a hard
"pegwood" stick sharpened to a fine point inside the pivot holes. Some hardened
grime, which the cleaning machine doesn't eliminate, must also must be removed
with special solvents.
machine is fine for removing general grime and returning a bright polish to the
plates and gears. But only hand cleaning removes hardened dirt and oil INSIDE the
pivot holes. Over the years, old oil dries to a varnish-like hardness inside the pivot
holes , and must be removed by "pegging out" the holes, that is, turning a hard
"pegwood" stick sharpened to a fine point inside the pivot holes. Some hardened
grime, which the cleaning machine doesn't eliminate, must also must be removed
with special solvents.
4) The next step is polishing all the pivots, the fine ends of the arbors (gear shafts)
that turn in the pivot holes in the main plates. This is done on a watchmakers lathe
by polishing each pivot with several increasingly fine grades of abrasive while it
spins in the lathe. The end result of proper pivot polishing is what is called a "mirror
finish" on the pivots, which will cause the least amount of friction as the gears turn
in the completed clock. In some severe cases, the pivots are worn so deeply and
unevenly that they must be refaced by cutting down past the wear with a lathe
cutting tool.
that turn in the pivot holes in the main plates. This is done on a watchmakers lathe
by polishing each pivot with several increasingly fine grades of abrasive while it
spins in the lathe. The end result of proper pivot polishing is what is called a "mirror
finish" on the pivots, which will cause the least amount of friction as the gears turn
in the completed clock. In some severe cases, the pivots are worn so deeply and
unevenly that they must be refaced by cutting down past the wear with a lathe
cutting tool.
5) After the pivots are polished, I turn to the pivot holes, the "bearings" that the
pivots turn in. These holes wear oversize and egg-shaped over years of turning
with a force that always pushes them in the same direction. The egg-shape of the
worn holes eliminates the tolerance that the pivots must have (the 2 to 4 thousands
of an inch that the hole must be bigger than the pivot in order to turn freely).
Extremely bad wear will even move the pivot off center, and cause the gears not to
mesh properly.
These problems are solved by "rebushing", a process of reaming out the worn
holes and pressing or riveting in new bushings, which can then be individually sized
to the 2 to 4 thousandths of inch tolerance that is required. In the severe cases
where the pivot hole has lost its center, the original center point must be found
again, and the new hole drilled at that point, not at the drifted incorrect center that
the wear has caused.
Finally, the new pivot holes are polished much as the pivots were, except in this
case with smooth broaches which not only polish the inside of the hole, but also
"work-harden" it for long life.
pivots turn in. These holes wear oversize and egg-shaped over years of turning
with a force that always pushes them in the same direction. The egg-shape of the
worn holes eliminates the tolerance that the pivots must have (the 2 to 4 thousands
of an inch that the hole must be bigger than the pivot in order to turn freely).
Extremely bad wear will even move the pivot off center, and cause the gears not to
mesh properly.
These problems are solved by "rebushing", a process of reaming out the worn
holes and pressing or riveting in new bushings, which can then be individually sized
to the 2 to 4 thousandths of inch tolerance that is required. In the severe cases
where the pivot hole has lost its center, the original center point must be found
again, and the new hole drilled at that point, not at the drifted incorrect center that
the wear has caused.
Finally, the new pivot holes are polished much as the pivots were, except in this
case with smooth broaches which not only polish the inside of the hole, but also
"work-harden" it for long life.
6) There are usually various other repairs to attend to next; bent or broken pins,
bent arbors, broken springs, and so forth. After these odds and ends are
completed, I turn to the mainsprings.
Often or usually, the mainsprings have lost their "springiness". When released from
their barrels or assembly clamps, they sometimes uncoil hardly at all. In a common
American 8-day clock, for example, the springs should uncoil to a circle at least a
foot in diameter. (A brand new spring will uncoil much more than that). It is common
to see them open only a couple inches; they have become "set" by years of
compression. Set mainsprings must be replaced or the clock will run only a short
time, perhaps two or three days instead of the full eight.
bent arbors, broken springs, and so forth. After these odds and ends are
completed, I turn to the mainsprings.
Often or usually, the mainsprings have lost their "springiness". When released from
their barrels or assembly clamps, they sometimes uncoil hardly at all. In a common
American 8-day clock, for example, the springs should uncoil to a circle at least a
foot in diameter. (A brand new spring will uncoil much more than that). It is common
to see them open only a couple inches; they have become "set" by years of
compression. Set mainsprings must be replaced or the clock will run only a short
time, perhaps two or three days instead of the full eight.
7) After replacing mainsprings as needed, it is time to finally reassemble the
movement. All the gears and levers are set in place in one of the plates, then the
other plate is carefully lowered over it. One by one, the pivots of each gear are
slipped into their pivot holes while gentle pressure is exerted on the two plates. The
very fine pivots of the smallest gears are easily bent or broken, so care must be
taken not to damage them. Finally, everything is in place, the plates slip together
and the nuts or screws that hold them together are reattached.
But this isn't the end of the reassembly. Certain gears have pins on them that must
align perfectly with a pin or lever on another gear or on one of the plates. Often,
the plates have to be separated and reassembled several times before everything
is indexed correctly with everything else.
movement. All the gears and levers are set in place in one of the plates, then the
other plate is carefully lowered over it. One by one, the pivots of each gear are
slipped into their pivot holes while gentle pressure is exerted on the two plates. The
very fine pivots of the smallest gears are easily bent or broken, so care must be
taken not to damage them. Finally, everything is in place, the plates slip together
and the nuts or screws that hold them together are reattached.
But this isn't the end of the reassembly. Certain gears have pins on them that must
align perfectly with a pin or lever on another gear or on one of the plates. Often,
the plates have to be separated and reassembled several times before everything
is indexed correctly with everything else.
8) All that's left now is lubricating the newly repaired movement, test running it and
regulating it. Minor adjustments are almost always required. After a minimum of 1
to 2 weeks running time, the repair is completed, and the clock is ready to be
returned to its owner.
regulating it. Minor adjustments are almost always required. After a minimum of 1
to 2 weeks running time, the repair is completed, and the clock is ready to be
returned to its owner.
Nothing to it, huh?
| It is a principle of professional clock repair never to use "unworkmanlike" methods or techniques, and never to perform a repair in a manner that will make the work more difficult for the next repairer who services the clock. |
| WHAT THE REPAIR DOES NOT INCLUDE |
The Complete Repair, or overhaul, does NOT include any case work, that is, refinishing or polishing of the case, regilding of
goldtone metal decorative parts or other repairs to the case or decorative attachments. It also does not include refinishing or
touchup of the dial (face), resilvering of metal dial parts or polishing of brass dials or pendulums. And it does not include glass
replacement.
Most such case work is available at extra cost, which can sometimes be substantial. I discourage complete refinishing and
especially, dial repainting or reverse glass repainting unless the damage is very severe. The value of an antique clock with the dial
paint chipping off slightly will remain greater if left alone than if the dial is completely repainted or replaced. Of course, there is a
point where damage is so great that repainting or replacing will at least not hurt, and may improve, the value of the clock. This is
often seen in American gingerbread clocks, where the painted dial may become almost completely unreadable due to chipped
paint.
I can discuss all this type of work with you, and give you a separate estimate or opinion on such repairs.
In a complete repair, the replaced bushings will be minimally visible on the plate, but very neatly done. Most people not familiar with
clock repair will be unable to distinguish them from original construction. In repairs of Fine Antique clocks, I usually finish off each
bushing by chamfering the new pivot, so that it is virtually invisible. I can do this for any clock, but it will of course increase the
repair cost.
goldtone metal decorative parts or other repairs to the case or decorative attachments. It also does not include refinishing or
touchup of the dial (face), resilvering of metal dial parts or polishing of brass dials or pendulums. And it does not include glass
replacement.
Most such case work is available at extra cost, which can sometimes be substantial. I discourage complete refinishing and
especially, dial repainting or reverse glass repainting unless the damage is very severe. The value of an antique clock with the dial
paint chipping off slightly will remain greater if left alone than if the dial is completely repainted or replaced. Of course, there is a
point where damage is so great that repainting or replacing will at least not hurt, and may improve, the value of the clock. This is
often seen in American gingerbread clocks, where the painted dial may become almost completely unreadable due to chipped
paint.
I can discuss all this type of work with you, and give you a separate estimate or opinion on such repairs.
In a complete repair, the replaced bushings will be minimally visible on the plate, but very neatly done. Most people not familiar with
clock repair will be unable to distinguish them from original construction. In repairs of Fine Antique clocks, I usually finish off each
bushing by chamfering the new pivot, so that it is virtually invisible. I can do this for any clock, but it will of course increase the
repair cost.
In the upper right of the left picture, a
badly worn bearing. On the right, the
same bearing with the pivot pushed
back into place. The pivot, being too
short to extend beyond the plate, has
bored a path into the plate more than
half the diameter of the pivot.
badly worn bearing. On the right, the
same bearing with the pivot pushed
back into place. The pivot, being too
short to extend beyond the plate, has
bored a path into the plate more than
half the diameter of the pivot.
Another worn bearing.
This pivot is on the end of
the shaft which holds the
Great Wheel, which in
turn holds the chain (or
cable) connected to the
weight. The constant
downward pull of the
weight as the wheel turns
has worn the pivot in a
downward direction. The
black crescent shape at
the top of the pivot is not
a shadow, it is the original
pivot hole.
This pivot is on the end of
the shaft which holds the
Great Wheel, which in
turn holds the chain (or
cable) connected to the
weight. The constant
downward pull of the
weight as the wheel turns
has worn the pivot in a
downward direction. The
black crescent shape at
the top of the pivot is not
a shadow, it is the original
pivot hole.
The black, greasy gunk around each
of these three pivots is a mixture of
accumulated old oil and finely ground
metal from the plate and pivot. This
is an extremely bad case, and much
less accumulation can be a sign of
bearing wear. But, either way, this is
a sure sign of a movement that is in
need of an overhaul.
of these three pivots is a mixture of
accumulated old oil and finely ground
metal from the plate and pivot. This
is an extremely bad case, and much
less accumulation can be a sign of
bearing wear. But, either way, this is
a sure sign of a movement that is in
need of an overhaul.
A particularly egregious example of a "Pin
Punch" repair, a shortcut method of repairing
worn bearings. Often without even
disassembling the movement, the clock
butcher uses a pointed punch to make a
circle or arc of indentations around the worn
bearing, theoretically closing the hole back to
its original smaller dimension. This, of
course, results in an uneven and unsmooth
hole, and thins the metal of the plate, making
it weaker.
Punch" repair, a shortcut method of repairing
worn bearings. Often without even
disassembling the movement, the clock
butcher uses a pointed punch to make a
circle or arc of indentations around the worn
bearing, theoretically closing the hole back to
its original smaller dimension. This, of
course, results in an uneven and unsmooth
hole, and thins the metal of the plate, making
it weaker.
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WHY OVERHAUL?
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