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Restoration of an antique Dutch Clock

We are currently involved in the restoration of a "Friese Stoelklok", purchased in a local auction some time ago. We thought that clock enthusiasts might be interested in seeing the progress of the project. Comments and suggestions will also be welcome.


Click on any picture for a larger image

History and condition


1. Clock as purchased 2. Lead castings 3. Lead castings

As Purchased


Nothing is known of the clock's history. I bought it at a small auction house, knowing very little about it, except that it looked interesting. It looked as if it had been in a fire, with thick deposits of sooty dirt all over. The dial had scorch marks? and bubbling of the paint. There was little real damage, however, and it seemed a good candidate for restoration.


The dial

The paint on the iron dial was in poor condition, but enough detail remained to be confident about the style of the numerals and the decoration to the actual dial.


4. The Original dial 5. Enhancing the picture reveals more detail

5a. Cleaning reveals more 6. First draft of the restoration by Tim Garrett


Removing the old paint revealed marks scratched into the dial with the outline of the dial. They show either that the dial painter changed his mind, or that it has been repainted before.

Some details of the picture above the dial were revealed on cleaning and examining with UV light, but the restoration must be speculative. Traditional designs often included rustic scenes with houses, windmills and boats. We identified at least 2 horses and human figures.

6a. an appropriately pastoral scene added.

These clocks were decorated with gilt lead castings. Some of these were present, but those surrounding the dial are missing (see below for restoration). The picture below gives an idea of what a complete clock should look like.



The Case

The name "Stoelklok" relates to the chair-like platform on which the clock stands. It consists of a backboard, 27 inches high, sawn into the shape of 2 mermaids at the sides, an arched top, and decorative bottom portion. From this projects a platform for the clock to stand on (on its own little stool see - fig. 11 & 12), and a hood to cover the top.

These wall brackets were painted with various designs, and often brightly coloured. Later versions have brightly painted mermaids as in fig. 7, but there is no evidence of anything other than a restrained yellow band around the outline, so I have reluctantly given up the idea of garishly painted mermaids.

The repainting of the backboard and dial have been entrusted to my friend Tim Garrett of


The Movement

The Friese stoelklok may be criticised horologically - the wide-swinging, short pendulum and verge escapement are not designed for precision timekeeping, but they are uniquely beautiful and ingenious mechanisms.

There are many variations on the theme, but this particular clock has "Dutch Striking" on 2 bells and an alarum. The striking train is behind the going train. The alarum wheel can be seen at the top in the front of the movement. It was chain driven with Huygens' endless system, and would have had brass shelled weights.

The movement of this clock is in more or less sound 7condition, although dirty and with some surface corrosion. It has been clumsily converted to anchor escapement. If it had been done expertly, I would probably have left it as part of the clock's history, but it is unlikely to work well, so I will convert it back to the original verge by replacing the escape wheel and third wheel together with the verge. The pendulum is missing.


Views of the movement (before cleaning!)


At the time of writing, the movement has been dismantled and cleaned twice. The next stage is to remove the verdigris and rust, then it can be cleaned properly and polished.



Work on this clock is necessarily slow, as it has to be fitted around more profitable enterprises! However, I have now made some progress on retoring the lead castings.

The original pieces were in much better condition than I had thought - they had been covered in thick paint and all the detail was lost. I cleaned them in caustic soda to remove the paint, then soldered the broken pieces together:

Side top fret and stoel surrounds

Top of hood

Top of dial

The pieces were glued to a board, and the missing portions built up with modelling clay.

A barrier was built around the master, using Lego bricks and pieces of wood and plastic, then catalysed silicone rubber was poured over the model. I used a hard red silicon rubber called RTV-101. Although it is more expensive and messy to use, it is tough and heat resistant, so the moulds will last longer. If there are significant undercuts a softer rubber must be used. When the rubber had cured, the mould was carefully removed.

The moulds ready for casting


I cast a plaster backing onto these 2 moulds to allow a thinner layer of rubber to be used.


These 2 have already been used for casting. They are coloured with graphite powder, used to prevent the metal sticking to the mould. mould6.jpg


Note the sprue channels cut into the rubber. Without these, the metal cannot escape and will be cast too thick.

The metal I am using is a low melt alloy of tin, antimony and lead, melting at 243C. The melting point of pure lead is too high for the silicone rubber moulds.

I was uncertain whether it would give enough detail, as a certain amount of pressure is needed to press the metal into the mould. In practice this was not a problem with these relatively heavy castings - the weight of metal is sufficent to force the molten metal into the fine detail. The metal was melted in an old saucepan over a gas burner and poured into the mould. Failures can be re-melted as often as necessary.

Finished castings

The full set of new castings






Rivetted to the dial - ready for painting and gilding.

The finished dial.


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