Here’s an Ansonia porcelain-cased mantel clock I repaired for a customer. The escapement is visible in the dial, adding interesting animation to the clock. The case is marked on the back “1755 Bonn Germany La Palma”. So I assume that means it is a “Royal Bonn” porcelain case, made by the company famous for fine porcelain vases. The case is 11 3/4 inches tall and 14 3/8 inches wide, and the minute hand is 1 7/8 inches long.
I initially overhauled this clock in September 2003, and it ran well until the time mainspring broke in September 2023. It had developed very little wear during these 20 years of running and was still fairly clean inside and the oil was still fluid.



Repair job 3159 and 8907. On the first overhaul in 2003 I polished all pivots except for the mainwheels, and installed 11 bushings. I also reversed the worn pinion wires in the escape wheel pinion.
On the second overhaul in 2023 I polished the four mainwheel pivots, and found that the other pivots still looked excellent. There was no observable pivot hole or bushing wear.
The original mainsprings are the following sizes:
Strike: 3/4 by 0.013 inch
Time: 5.8 by 0.013 inch
Both are loop-end springs.
The time mainspring was broken, and I found part number MS168 (5/8 by 0.013 by 105″) from Merritt’s Clocks & Repair Supplies to replace it. This is a hole-end mainspring, so I fastened the loop from the original time spring onto the new spring (using a new brass rivet). This new mainspring provides plenty of power (probably more than necessary) but I couldn’t locate any thinner springs with length close to long enough (at least 96 inches).
It always pleases me to observe that my repair work held up well. If you have an American antique clock that needs to be repaired, please see my business website, billsclockworks.com for pricing and information.
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