Seth Thomas Antique Clock Repair

Bill’s Clockworks repairs antique Seth Thomas clocks. We give a two-year warranty on wind-up clock repair.

We are in Flora, Indiana (about an hour north of Indianapolis). Besides local repair work, we are happy to have smaller clocks shipped to us for repair (such as mantel clocks and smaller shelf clocks). We repair pendulum clocks, but not clocks with a balance wheel.

Bill's Clockworks takes the time to repair your clock properly. We disassemble the movement and clean and examine it. We replace overly strong mainsprings with thinner springs to give your clock a long life. We burnish or polish the pivots and bush worn pivot holes. We do other necessary repairs and clean the parts again, then assemble, lubricate and adjust and test the movement.

We show examples of our repair prices below. The price will be higher if there are any damaged gears. Now and then, a clock will have severely worn mainwheel teeth (the mainwheel is the gear that the mainspring is on). An overly strong mainspring may have caused the wear over the years. Sometimes the wear is not bad enough to affect the operation of the clock, but other times it causes a rough gear action. To fix this, sometimes I can find a replacement gear from the parts I have from old clocks, and add only about $50 to $75 to the repair bill. Sometimes I have to have my gear cutter make a new gear ring, which will add about $150 to the repair price. Along with this, I'll install a new thinner mainspring that will cause less wear in the future.

Lately, I've run into many antique American antique clocks with damaged ratchet gears (the part that makes the clicking sound as you wind the clock). A worn ratchet can make winding the clock dangerous, as the key could suddenly unwind, injuring your hand. Often I can't tell if the ratchet is bad until I've disassembled and cleaned the clock. I can have a new ratchet made for around $125, and I may decline to complete the repair job if you decide not to have that done, as I don't want to risk a customer being injured by their clock.

At your request, we will beautify your clock while keeping the finish original. For about $40 - $80, we will clean the case and touch up the finish.

See my clock information blog for examples of clocks I've repaired recently.

Average Prices for Movement Overhaul

8-day time and strike: $600 - $750

1-day time and strike: $500 - $700

8-day time only: $500 - $650

1-day time only: $500 - $600

Add around $125 - $150 if a ratchet or mainwheel needs replacing (as explained above). The overhaul will have a two-year warranty.

We also repair Seth Thomas windup chime clocks.

These prices are for pendulum clocks, either weight driven or spring driven. Any case work will be extra.

The most popular antique Seth Thomas mantel clock movement is the No. 89 and its many variations. They used this movement in mantel and shelf clocks and from about 1900 to 1940. Before that, they used a movement with the escapement at the back in mantel clocks. I will overhaul these movements for $550 - $750 (or more if there is a worn out or damaged gear). The No. 89 movement is one of the best mantel clock movements ever designed. It uses thin mainsprings (about 0.017") to prevent excessive wear, and efficiently uses power by having a semi-deadbeat escapement.

Our repair backlog is about 3 - 5 months. Please contact us about sending a clock for repair.

Examples of antique Seth Thomas clocks I've repaired

Seth Thomas 6 pillar adamantine clock Seth Thomas 8 pillar adamantine clock Seth Thomas 4 pillar adamantine clock Seth Thomas adamantine clock Seth Thomas 6 pillar adamantine clock Seth Thomas 2 pillar adamantine clock

Above: Examples of Seth Thomas Adamantine Mantel Clocks

History of Seth Thomas Adamantine mantel clocks
Seth Thomas Kitchen model shelf clock

"Kitchen", 1868 to 1878

Seth Thomas Round Band shelf clock

"Round Band" model, made from ca. 1860 to 1915. This example ca. 1865

Seth Thomas Octagon Top shelf clock

Octagon top, made from ca. 1862 to 1879

See more examples of small shelf clocks

See more ogee examples

History of Seth Thomas ogee clocks and other 30-hour weight clocks

Seth Thomas 30 hour ogee

30 hour ogee or o.g., made from 1842 to 1913

Seth Thomas 30 hour half column clock

30 hour half column

Seth Thomas eight day cornice and column clock

Eight-day cornice and column, made from ca. 1860 to 1913

Seth Thomas schoolhouse clock

Drop octagon or schoolhouse clock

Seth Thomas No. 1 extra regulator

Number 1 Extra regulator

Seth Thomas oak cased wall clock

Unidentified wall clock

Packing for Shipping

Note: I recommend shipping only mantel clocks, small shelf clocks, and small wall clocks. Please bring larger wall and shelf clocks in person.

Please send the key so I can check how well it fits. I will replace it if it is worn out (I will return the original to you). Please let me know if you need a key.

If there is painted glass in the front door, please remove the door and don't send it, to avoid the chance of breakage. Usually you can remove four of the hinge screws and the door will come off.

Before packing the clock, remove the pendulum bob and wrap it and the key in bubble wrap. Gently tape the pendulum rod to the movement to prevent motion, and put padding around the hammers, gong or chime rods inside the clock to immobilize them. On clocks with painted glass in the door, it is best to remove the door (and not send it to me) to prevent damage. Wrap the entire clock in several layers of bubble wrap. Use a box that gives 2 - 3 inches space around the wrapped clock on ALL sides. Put a 2 - 3 inch layer of foam packing peanuts in the bottom of the box. Put in the clock and fill the space firmly with peanuts. Include the wrapped key and pendulum bob. There should be a slight pressure when closing the box to keep the clock from moving around.

Note: Many packing places today (such as The UPS Store) don't use packing peanuts anymore. In this case, wrap the clock in bubble wrap 4 to 6 inches thick; then 3 or 4 inches of firmly wadded brown paper will provide good padding between the wrapped clock and the box.

Proper Mainsprings for American Antique Clocks

See my Clock Information Blog for more information about mainsprings for American clocks.

Bill’s Clockworks repairs your clock properly so that it will have a long life. Some repair shops are using mainsprings that are too strong for your clock. Here is some information about the proper springs for American antique clocks.

Seth Thomas Mainsprings:

The popular Seth Thomas #89 mantel clock movement originally used 0.017" thick mainsprings. Some repair shops actually take these out and put in stronger springs (even when the originals are good!) We keep the originals in the clock if they are good. If a spring needs replacing (or has a replacement that is too strong), we install a 0.0165" or thinner mainspring. Some Seth Thomas time and strike mantel clocks made in the USA in the 1940s and 1950s had absurdly strong mainsprings. I routinely install MUCH thinner springs and often need to replace badly worn gears.

History of Seth Thomas Clock Company

Seth Thomas Clock Company was one of the most prolific and long-lived clock companies. The quality of their products was always above average. Seth Thomas must have sold many clocks in the Lafayette, Indiana area, for out of all the antique clocks we repair for local customers, about 40% are Seth Thomas clocks.

Many American clock factories in the 19th century suffered factory fires, but Seth Thomas was fortunate in this respect. Through conservative growth and taking advantage of the new ideas of others, Seth Thomas enjoyed financial stability, whereas many other companies faced financial difficulties.

Starring in the 1860s, Seth Thomas Clock Company introduced many new styles of clocks. They introduced regulator clocks in 1860. Seth Thomas purchased the patterns and machinery for these in 1859 from the creditors of bankrupt clockmaker Silas B. Terry. They introduced spring driven clocks ca. 1855 to 1860. They made perpetual calendar clocks from ca. 1863 to 1917. Some of the most popular later types include walnut kitchen clocks, made from 1884 to 1909; marble clocks, 1887 to ca. 1895; black (Adamantine finish) wood mantel clocks, ca. 1885 to 1917; black enameled iron cased clocks, 1892 to ca. 1895; oak kitchen clocks, 1890 to ca. 1915; tambour clocks, introduced in 1904; chime clocks, introduced in 1909; and electric A/C clocks, introduced in 1928.

Many Seth Thomas clocks from 1881 to 1918 have a date code stamped in ink on the case back or bottom. Usually, the year is printed in reverse, followed by a letter A—L representing the month. For example, April 1897 would appear as 7981 D.

We also repair Seth Thomas windup chime clocks.

Our repair backlog is about 3 - 5 months. Please contact us about sending a clock for repair.