French Marble Clock

timbo19

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Dec 28, 2019
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Hi - I have just been ask by some French friends to repair and clean this clock. It has been in the family since at least the late 19C. The plinths and columns are marble (the clock is extremely heavy.
I am wondering how best to clean the marble - also the dial, feet and decoration are brass coloured but I am not sure they are actually brass - would they always have been this dull colour?
The clock does not currently work but I think the problem is due to the pendulum - when attached it rubs on the bottom plinth and seem too long. The suspension appears to be bent - I think the clock may have been damaged when being moved. There are some markings on the back but nothing on the case - I have tried to photograph some markings which have been scrtched on.
Any help on who may have made the clock and the best way to start restoring it would be very helpful
Many thanks
Timbo19

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JTD

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The clock does not currently work but I think the problem is due to the pendulum - when attached it rubs on the bottom plinth and seem too long. The suspension appears to be bent
As far as I can see from you photo, the suspension spring is entirely broken and I am not sure how you could have attached the pendulum.

As for the correct length, the marks 7. 7 is likely the pendulum length expressed in old French inches, pouce and ligne, 12ligne = 1 pouce.

I am wondering how best to clean the marble - also the dial, feet and decoration are brass coloured but I am not sure they are actually brass - would they always have been this dull colour?
Be very careful with cleaning the marble (if it is marble). For the time being I should just clean off surface dust.

Yes, the metalwork would have been bright. They decorative pieces may have been gilded rather than polished brass. You pictures are not sharp enough to be sure.

It is a nice clock and well worth restoring.

JTD
 

timbo19

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Thanks JTD. When I took the suspension off I could clearly see it was broken - I have been able to order a new one which should arrive shortly.
Yes, I think it is marble, or at least the base and top are - not sure sure about the columns. I have read to be very careful in cleaning marble, so I will do, as you suggest, and only clean-off the surface dust.
Do you know If there is a way I can restore the metalwork? - I don't want to damage the marble. As it is a friend's family heirloom, I am inclined just to get it working and return it to them with the case as it is.
Thanks for your advice
Timbo
 

svenedin

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For the metalwork I’d remove it from the clock and clean gently with soapy water either in an ultrasonic or with a soft toothbrush (an electric ultrasonic toothbrush works well). Rinse then dry carefully in a very low oven. After that assess what you’ve got.
 

timbo19

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Thanks Stphen. I have not dealt with this type of case before and as I said above, I am very cautious as it is a friend's family heirloom. There are 4 nuts under the base that look as though the rods go up through the columns. If this is correct, am I likely to find inside the plinths etc how the metalwork is attached - there is no visible sign of how they are attached,from the front. The column heads and feet will presumably come off when I release the 4 nuts (visible in photo above)
Tim
 

svenedin

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Thanks Stphen. I have not dealt with this type of case before and as I said above, I am very cautious as it is a friend's family heirloom. There are 4 nuts under the base that look as though the rods go up through the columns. If this is correct, am I likely to find inside the plinths etc how the metalwork is attached - there is no visible sign of how they are attached,from the front. The column heads and feet will presumably come off when I release the 4 nuts (visible in photo above)
Tim
I don’t know exactly how your clock is held together to be honest. I’ve worked on a black “marble” and it was quite straightforward to remove the metalwork but it didn’t have columns like your clock. On my black marble the case is also held together with plaster. I definitely would not try to clean the metalwork in situ with any wet method as the marble or alabaster or whatever it is could end up stained. If there’s no obvious way to safely remove the metalwork best to leave it rather than damage an heirloom. A dry soft brush might at least get the dust off. Something like a soft shoe brush
 

JTD

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These clocks are very fragile and I think you might be well advised not to take the case apart if you are not familiar with this type of case. The nuts may be difficult to remove and there is always the danger of damage. The columns themselves will have a hole from top to bottom in which the metal rod runs, and are very easy to break in half.

The clock would look very fine indeed if all the brightwork were cleaned and polished but it might be as well to leave that to a professional, since it is not yours and is a precious heirloom.

JTD
 

timbo19

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Thanks everyone for your advice - I will be very cautious and just try to get the clock working again - after all, that was the principle reason for them asking for my assistance. I will let you know when it is working again. Thanks
Tim
 

timbo19

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I have cleaned the clock carefully with a soft brush and a little water and it is looking much better - still looks old and good but not pristine. The new suspension has arrived and while not identical, it is very close to the original. However, I have a problem, when the pendulum swings it tends to oscillate and it seems that this oscillation means that because it is not swinging truly that it stops swinging after 5 or 10 minutes. Having studied the fitting, it appears that the problem is that the hole at the top of the suspension through which the pin goes to connect it to the mechanism is much larger than the original thereby allowing the suspension to move significantly on the pin when the pendulum swings. I can try and find another suspension but I gather suspensions for old french clocks are difficult to find. I do not want to alter anything on the original clock and I wonder if anyone has met this same problem and found a solution.
Tim
 

JTD

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I am not sure if you mean the size of the hole in the top of the suspension spring or the hole in the chops in which the suspension spring hangs. But you could try using a thicker pin.

Having said that, I am not truly convinced that this is the cause of your oscillating pendulum. It might be, but it would help if you could post a video showing both the suspension (at the top) and the oscillating pendulum.

JTD
 

timbo19

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Thanks - it is the hole in the top of the suspension spring itself and not the holes in the chops. The chop holes are smaller than the suspension hole. To use a thicker pin I would need to drill the chop holes - not something I want to do.
I will send a video of the suspension and oscillating pendulum later to day
Tim
 

timbo19

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JTD - our internet has been down so unable to send video - but we have it now for a while.. However, when I re-assembled the suspension I found that the pin holding the suspension in the chop was tapered - I changed it for a straight pin and now the clock works well. The tapered pin must have been enough to make the pedulum oscillate when swinging.
Only one, I hope, remaining problem and that is that the clock is running slow and I guess this is because the new suspension dimensions are not exactly the same as the original but very close and has made the pendulum a little longer. I cannot turn the adjustment screw any further to make the pendulum shorter. I am trying reducing the weight of the pendulum by removing some of the shot in the base container of the pendulum. Do you have any other ideas of how to shorten the length? Many thanks
Tim
 

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shutterbug

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Perhaps this would be better served in the repair forum. You might try posting the repair questions over there.
 

timbo19

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Thanks 'shutterbug' for suggestion - I will add a question on to repair forum
Tim
 

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