Here’s a Seth Thomas clock I repaired called “Sentinel #1”. It has a mahogany case, 16 3/4 by 9 inches with a 5″ dial and “ST” hands (the minute hand has a letter S worked into its design, and the hour hand has a letter T). The movement is No. 89 8-day, striking on a cathedral gong. The 1931 Seth Thomas catalog shows this clock, with a retail price of $12.50. I think the dial is aluminum with printed numerals (even though the catalog says silver-plated, that may have been an earlier version).
Repair job 8691. The No. 89 is an efficient movement that can use thinner mainsprings than are usually supplied with it. When I received the clock for repair, the time mainspring was 3/4 by 0.0187″, too strong and not original. The strike mainspring was 3/4 by 0.0165″ but had a squeaky action after cleaning and lubricating (this squeaky action, in my experience, means the spring may fail soon). I replaced both mainsprings with MS298 11/16 by 0.015 by 108″ springs.
I burnished or polished the pivots and installed 14 bushings. I tightened the click rivets, opened the pallets slightly and adjusted the depth. The mainwheel teeth have little wear, 5% or less.
The cleaning solution I use now is Magic Cast from Timesavers. It was made for years under the name Historic Timekeepers, and I used it from 1995 until it was discontinued several years ago. For very dirty clocks I will pre-clean the parts in a different batch of solution, and save the good cleaner for final cleaning or clocks that aren’t super dirty.
Share this post:
