Inpainting a Seth Thomas clock dial – Part 1

This is Part I of a two part series. Part one covers the first three steps in renewing a Seth Thomas clock dial. In Part II the decorative corner design is restored.

Seth Thomas column and cornice “Empire” style time and strike weight driven shelf clock, as found

Inpainting is the process of reconstructing lost or deteriorated parts of a clock dial. In the museum world, in the case of a valuable painting, this task would be carried out by a skilled art conservator or art restorer. Inpainting, as opposed to repainting and restoring the entire dial, renews the dial using a few simple techniques.

Some of the methods can be found in T. E. Temple’s excellent resource book entitled Extreme Restoration.

Inpainting is cost effective and can be done on the home work bench

Inpainting certainly does not meet the higher professional standards of a service such as The Dial House, which perform exemplary work but I will not have a dial professionally restored if the cost is twice what the clock is worth. There will always be occasions when a professional restoration is justifiable, however.

Inpainting is cost effective and can be done on the home work bench.

For this project I chose the dial pan from a Seth Thomas column and cornice clock circa 1865.

Close-up view of dial in as-found condition, floral corners are almost completely faded or missing altogether

The dial, which is in poor condition, is likely original to the clock and rather than changing it out for a similar one it was an ideal candidate for inpainting. The numerals are faded, large sections are without paint, half of the time track detail is missing or faded and the corner floral details are barely visible.

Elements of a clock dial


  • Artist paint brushes, a number 3 would be the smallest
  • Multi surface water-based acrylic paint, white, yellow. red, black and green
  • Fine-tip black Sharpie or Artists pen
  • Math compass, scriber
  • Old credit card (flexible on a convex time track)
  • Q-tips

Inpainting in steps

There are 4 steps to inpainting.

  1. Mix paint to match and cover the large and small paint loss sections,
  2. Touch up the numerals with black paint,
  3. Redraw missing sections of the chapter ring and fine line details of the numerals and
  4. Reproduce the designs in the 4 corners

Step 1 – paint large and small sections of the dial

Using a water-based all surface acrylic paint I attempted to replicate the aged dial. I mixed white, yellow and black paint to closely match the correct tone of the dial surface. It will not be perfect but it is close. I applied the mixed paint to the bare areas of the dial and let dry.

Large and small areas of the dial are painted

Step 2 – the numerals

Take a medium size artist paint brush and carefully fill in the Roman numerals with black paint using long strokes. Try to maintain a steady hand during this phase. Water-based acrylic paint allows the removal of paint with a damp cloth if a mistake is made. Don’t worry about the thin lines yet, that step will come later.

Larger areas of the numerals are touched up

Step 3 – chapter ring and fine line details

The next step is to retrace the chapter ring and line details using a fine-tip black Sharpie or Artists pen. There is no margin for error as the ink is permanent.

Alligator clips and cardboard stock

The chapter ring consists of two concentric circles placed close together. Establish exact centre of the dial and scribe the chapter ring or time track using a compass attached to the sharpie pen then scribe the faded radial minute marks on the chapter ring.

Establish centre for math compass

Insert the sharpie pen into the pencil slot of a math compass and tightly secure it.

Use a math compass with black fine-tip Sharpie pen to draw chapter rings
Left side of dial, concentric circles are scribed, minute marks are next
Your compass kit should include a scriber to establish minute marks

Take an old credit card, press it firmly against the convex time track and ink the minute marks.

Using an old credit card as a straight edge fill in the minute marks

Once the inner and outer rings of the time track are completed, press the credit card against the convex time track and using the Sharpie pen draw thin straight accent lines on each of the numerals. The effect is subtle but effective.

Time track completed
The dial is reinstalled on the clock to dry; next are the corner designs

I could comfortably stop at this point but I am anxious to apply my artistic technique to the floral patterns in the decorative corners.

This concludes Part I and now on to the last step, the decorative corners, Part II, in 4 days time.