Cost of a 3rd Level Service depends on the current condition and type of construction of the clock and will typically cost $800 to $1,000.
This is the next level of service and is for clocks in which maintenance has been deferred for a prolonged period of time, with notable degradation and breakdown of old lubricants. In such clocks, it’s common to find excessive residue, dirt, dust and metallic contamination from failed lubricant and wear. In such cases, removal of peripheral parts such as chime hammers, levers and cams, followed by ultrasonic cleaning of the remaining assembled movement and individual cleaning of the removed peripherals is recommended. Only clock movements in which no cleaning materials can be trapped are candidates for this service. This precludes clocks that have mainsprings in barrels that cannot be removed, short of total disassembly.
This service may include a number of specified individual repairs and adjustments. The final cost depends on the extent of removed peripherals and the number of repairs that are needed. This service includes:
On movements with barreled mainsprings that can be removed, the springs, and peripheral parts such as external lever systems that control the chiming are removed, for separate cleaning. Movements in poor condition that have barreled mainsprings that cannot be removed without complete disassembly are not candidates for a 3rd Level Service and may require a higher level of service. Ratchet, cable / chain safety inspections are made, as per item 2, Levels 1 & 2.
The semi-assembled movement and peripheral parts are then submerged in a detergent/ammonia based solution in a heated ultrasonic tank, to achieve a more thorough decontamination than what is possible with a 2nd Level Service. Upon completion of the ultrasonic cleaning, the solution is thoroughly rinsed away, and the movement and its separated peripheral parts are then dried with compressed air until all visible moisture is removed.
Finally, the escapement (where the tick-tock sound is produced — the clock’s timekeeping regulator) is adjusted to its optimal settings and the timekeeping accuracy is adjusted. Lever system adjustments are made as required and restored to safe settings, to improve the reliability of the quarter, half or hour strike. Conscientious gong, bell or chime adjustments are made so the clock will produce the most pleasing tones when striking the hours or chiming.