Seth Thomas Sentinel No. 4 Tambour Mantel Clock

Here’s a Seth Thomas Sentinel #4 tambour mantel clock I repaired. It’s an 8-day clock with hour and half-hour strike on a heavy wire gong (often called cathedral gong). The case is dark mahogany, and the dial is silvered brass with printed Arabic numerals. The movement is the No. 89, popular for many years, and very well designed and made. It has a semi-deadbeat escapement for efficiency, and can run on thinner mainsprings than many American movements. The clock was made around 1920.

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Repair job 6871. I had the dial refinished, and cleaned and blued the hands to look nice with the refinished dial. I polished the pivots and installed 17 bushings. A previous repairer had installed large diameter (3.5 mm) bushings, so it took extra work to properly install new bushings. I closed the verge and moved it closer to the escape wheel to set the drops.  The old strike mainspring had a “squeaky” action, so I installed a new 3/4 x .0158 x 120″ mainspring.

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  1. Bill,
    I have a Seth Thomas mantle clock- says Sentinel #3 on the bottom, but the mechanism is identical to the Tambour #4 you’re showing. It needs a pendulum and I’m having issues finding one. Additionally, the ‘driver’ for the pendulum looks different from yours- the hook is vertical, as opposed to horizontal. I’m guessing its been modded or bent for another bob assembly. Any help wood be greatly appreciated. Thank you

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