In my opinion ultrasonic cleaning machines are the best way to clean clock
mechanisms, if it is understood how they work, and what they do to metal. If petroleum
based cleaners are to be used , it is absolutely imperative to remember the following
information: The brass and steel metal in clocks has microscopic holes that the oil will
fill and hold a thin film on top. When the clock mechanisms are run through the
ultrasonic cleaner ; all the oil even the oil that is imbedded in the pores of the metal
is removed. When the surface is re-oiled the new oil will often be soaked up and the
result is the same as if the part had not even been oiled in the first place. Disassembly
is a must. It is not possible , in my opinion , to properly clean a clock mechanism
without disassembling it totally. It is best to use a cleaner and a rinse in separate
containers preferably 2 separate cleaning machines at a minimum. The ultrasonic
machines work by actually vibrating the liquid at about 15,000 hertz forming small
bubbles that effectively scrub the objects in the tank clean.
Water based cleaners: Often it will be necessary to use water based cleaners.
Be absolutely certain that all the moisture is removed from the mechanism before
re-assembly and if a dryer is used be aware that plastic parts will melt! I have seen
many clocks that have been destroyed by rust. Avoid using substances that are extremely
caustic or acidic , they may do a great job of cleaning the mechanism and make look
shiny and bright , but the steel parts will most certainly rust later and if this rust
is not removed , the mechanism will be destroyed.
Another way to clean is to use a tooth pick on the pivot holes. This takes
a long time , and is very tedious, but sometimes it is the only way to get the thing
cleaned. A small amount of cleaning solvent on the end of the tooth pick will make
it a faster operation. Twisting the toothpick slowly by hand probably is the best
way to insure that the pick wont break off in the hole. I find it necessary to use a
magnifier to check the Inside of the bushing to determine when it is clean.
I have found that cleaning mainsprings with an abrasive substance such as
sandpaper is ok as long as the spring surface is not scratched excessively. If the
surface of the spring is scratched, then friction will be added in direct proportion
to the extent of the scratches , quite possibly more than the old oil that was removed
by the substance in the first place. A self defeating situation at best!! Use fine steel
wool with cleaning solvent to remove the old oil. The old oil will often look like a
yellowish brown stain and can be mistaken for the color of the steel if you are not
aware of this. Some springs do have this color; so check if the stain can be removed
by fine steel wool and solvent, it is probably not the steel color!