Seth Thomas Round Top Mantel Clock

This Seth Thomas round top mantel clock uses the No. 89C movement, one of the popular 89 series. It is 8-day time and strike, with hour strike on a cathedral gong, and 1/2 hour strike on a bell. The dial is paper covered with celluloid.

The original time mainspring of 3/4 x 0.018 inches hadn’t caused much mainwheel tooth wear, so it was retained in the movement. The original strike mainspring of 3/4 x 0.0176 had a squeaky action, so I replaced it with a 3/4 x 0.0163 by 120 inch mainspring from Timesavers.

The movement was so sticky from old oil that I cleaned the parts first in lacquer thinner, then in the usual fluid (Historic Timekeepers) in the ultrasonic cleaning machine. The repairs included polishing pivots and installing 10 bushings, installing a new tension spring on the count lever, installing new pins in 2 pinions (T2 and S4) because of bent wires, and tightening the time click rivet. Also, the entry pallet was corroded so I polished it.

Repair job 5260.

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