French Mantle (Slate) Clock Movement

[Folkvisor]

The clock works but only when it wants to. I think it is just very dirty and in need of a good oiling.

There are a lot of flat brass screws that are proving very difficult to remove. Also the pins are really stuck in there and it is very difficult to pull them out. I don't want to damage the brass screws or the clock while repairing it. 

Is it possible to put the whole clock in a bath of naphtha to clean it; it may solve the stickiness? Or is that a really bad idea and I should simply proceed slowly getting it dismantled?

[StuartBaker104]

On 02/11/2017 at 10:40 PM, oldhippy said:

 French chalk is used to stop the brass work from tarnishing. You use a watch blower and blow the residue away this will clean the pivot holes.  

 

Thanks OH

[oldhippy]

1 hour ago, Folkvisor said:

The clock works but only when it wants to. I think it is just very dirty and in need of a good oiling.

There are a lot of flat brass screws that are proving very difficult to remove. Also the pins are really stuck in there and it is very difficult to pull them out. I don't want to damage the brass screws or the clock while repairing it. 

Is it possible to put the whole clock in a bath of naphtha to clean it; it may solve the stickiness? Or is that a really bad idea and I should simply proceed slowly getting it dismantled?

There should not be any brass screws they should all be steel. Try removing the pins with a pair of watchmaker’s pliers or you could use a punch and small hammer and knock them out. If the pins are rusted in, put oil around them and ease them out.

Never ever, put the whole movement in any liquid. The movement should be taken apart.  

[Folkvisor]

OK, good to know about not immersing the movement in liquid!

I put some penetrating oil around the pins. I'll just leave it over night. There's no rush; this clock hasn't been working for decades...

Perhaps the screws are just plated. In any case they are tight and I've used some penetrating oil on them as well.

Always an adventure...

[oldhippy]

I have never come across any French movements that have the screws plated, they are all steel right down to the smallest one that hold the   Are you sure its French and not an imitation, there are American and German but the pinions tend to be lantern and not solid. Any chance of some photos?

 

I keep remembering little things. Many movements with strike have tiny punch marks on the wheels this is to help in lining the wheels up in re-assembly so as to have them in the right order for the warning in the strike. Don’t worry if you cant get this right, as long as you have the wheel next to the fly wheel some way back. You can always remove the wheel with all the pins and place it back or forward. The three small plates, that hold the centre wheel the wheel between the centre and escape wheel plus the strike wheel with all the pins on those three screws tend to have punch marks the same as the three plates this is to help you so as you don’t mix them up. If you do mix them up sometimes the plates when screwed tight do not mesh with the main plate, but the pins in the small plates would be out of line so it is highly unlikely this could happen. Always put the barrel caps back on in the same place as when you take them off.  

Here is a 8 day French count wheel strike nicely polished but alas no work in blueing the screws, and poor pinning.

[Folkvisor]

The brass screws may be plated. They are on the arms fastening the clock into the case so have nothing to do with the clock itself.

The pins are going to be a problem. I'll just keep at it.

I will take photos and send you some Monday; I have a 6 hour rehearsal today for a musical.

Edited November 5, 2017 by Folkvisor

[oldhippy]

The screws that hold the movement into the case are screwed into the two straps. Thay have been replaced quite common too. 

[Folkvisor]

Yeah, that's the problem I think. It could well be that the screws are the wrong size. Trying to find a screwdriver that fits the slot exactly and won't slip is part of the problem.

[clockboy]

All of the French movements I have serviced the plates have been secured via  posts & pinned such as pic below. Maybe a pic would help to identify the movement.

 

[Folkvisor]

Sorry it's upside down.

 

[Folkvisor]

 

[Folkvisor]

I don't know why I always have a problem posting pics!

 

French Clock Photos.pages

 

[oldhippy]

I can't open the file. When you add a comment at the bottom of the box to the left it says Drag files here to attach, or choose file, click on choose file a window will open and you look for the file. The simple way is keep your file on the desk top that you want to upload, when the window opens look to the left you will have a list, click desktop and look for the file, when you have found it double click and it will upload. Close your window and look at the bottom left and it will tell you when the file has uploaded, you will see the photo, then just do what you normally do when making a post or reply.

Edited November 6, 2017 by oldhippy

[Folkvisor]

Maybe it's my iMac or the fact they are on Pages. I'll try turning them into a PDF and see what happens.

French Clock Photos.pages

[clockboy]

32 minutes ago, Folkvisor said:

Maybe it's my iMac or the fact they are on Pages. I'll try turning them into a PDF and see what happens.

French Clock Photos.pages

Have opened your pic. However for those without a Mac will not be able to open. Save the pic as a JPEG then choose files then double click on the selected pic then when loaded  click the + which will enter it into the post.

PS the pic is not showing a lot of detail. A pic of the front & rear plates will be better.

[Folkvisor]

OK, I'll try to do that tomorrow or Wednesday. We are in the midst of musical rehearsals...

[StuartBaker104]

So for those of us who can see the pictures, your clock carries a makers mark for Honore Pons. Although most likely it was made after the business had been sold to Delepine.

I also see the suspension spring is quite twisted which will stop the pendulum moving freely.

[Folkvisor]

I will pass all this onto the customer. Interesting stuff!

Can the spring be straightened without breaking it?

Dave

[oldhippy]

Help me out guys I still can't see thr photos.

[Folkvisor]

Perhaps I could email the photos to you. That should work.

Dave

[oldhippy]

This movement should be able to put its self in beat, providing the crutch and pallets have not been butcher.  The crutch should be friction tight to the pallets and are screwed on by means of a thread, you can tighten them if needs be because the collet is split, sometimes you might find some fool has soldered them, the same goes with the pallets, I don’t know why but I have found blobs of solder around the pallets. It has what is called rack striking and strikes on a bell. I cannot see the makers name or date. I can see the little punch marks on the screws and small plates, which I already mentioned. Take out the suspension spring and see if its twisted if so replace it. Looking at it in the movement it looks fine but looks can be deceiving. The movement doesn’t look that dirty I have seen a lot worse, so look for wear and check the springs. You will need a clock mainspring winder to remove both springs in the correct manner.    

 

About the regulator.

Most French clocks have a system for fine adjustment of the rate, which takes the form of a small square, which protrudes through the top of the dial, directly above 12 o'clock. The square is at the end of a rod, which at its other end is attached to a suspension block on the back plate of the movement. The suspension spring is fixed to the top of this block. Under the fixing point, the spring is held between two cheeks of a threaded block. Turning the square on the front of the dial raises or lowers the cheeks, altering the acting length of the suspension spring therefore altering the rate of the clock. Turning the key to the right will make the clock gain and turning to the left will make the clock lose.

[Folkvisor]

Yes, I agree that isn't all that dirty. The suspension spring is twisted. Can it be straightened? I'm not sure where I can buy another one.

The clock runs so the pallets etc isn't a huge problem; however, the clock needs to be tilted slightly toward 1 o'clock to work. If 12 is at the top it doesn't want to run.

Also, I don't thing it was pinned properly. They aren't tapered and they look suspiciously like decapitated tacks. I've used penetrating oil to get them out because I think they should be replaced with tapered pins but it's not going to be easy.

The striking mechanism works though.

Thank you for your detailed descriptions and help; if you ever need to know how to do a complete regulation on a Steinway Grand...just call a very experienced piano technician...they are even harder than French Slate Clocks...LOL

Dave

[StuartBaker104]

You can try to straighten the suspension spring, but it’s unlikely you will get it truly flat.

I seem to recall you are based in the US. In the UK I would start with Cousins https://www.cousinsuk.com/category/pendulum-clock-suspension-springs

 

[Folkvisor]

I'm in Canada so I will try Perrin's in Toronto 

[oldhippy]

Suspension springs should be easy to obtain. This type is very common.

How you have described your clock about it ticking, it is not in beat. What I have described before about the friction type pallets you should just give the pendulum a good swing and the clock should set its self in beat. Never bother to try to straighten the suspension spring; this will cause the pendulum to wobble during its action. Its action should be in a straight line, not something that goes all over the place; it can also cause poor timekeeping.