Mercury pendulum on grandfather clock

BOBJAYR

NAWCC Member
Mar 12, 2009
455
3
18
ARIZONA
Country
Got a request to repair, restore a grandfather clock
with a pendulum with mercury in the pendulum.

Need some advice.

What precautions should I use if I work on such a clock
and is it even advisable to do so since the pendulum
contains mercury.

Individual calls it a "Jewelers Regulator" and is
apparently about 8' tall.

Thanks, Bob
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
46,950
1,996
113
North Carolina
Country
Region
Keep the pendulum in an upright position when transporting and at all other times. No real danger from the mercury unless it spills, and it will if you lay it down. It's also VERY expensive to replace! Can we see a pic of the clock? I assume it's not a Grandfather, but a wall clock.
 

BOBJAYR

NAWCC Member
Mar 12, 2009
455
3
18
ARIZONA
Country
Thanks for your quick reply.

Have not seen clock yet. I will get photos
and send them in.

Thanks very much for the advice on how to transport pendulum. Had no idea
this could be a problem.

What problems do you incur if some spills out?

Thanks, Bob
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
46,950
1,996
113
North Carolina
Country
Region
If it spills, the clean up is very dangerous and difficult. It's best not to spill it!! The pendulum will attach with a screw. Hang on to it when you remove the screw. It's a very heavy pendulum! :) Probably 10 pounds or so.
 

novicetimekeeper

Registered User
Jul 26, 2015
11,178
938
113
Dorset
Country
Region
getting it back would be your main problem, it isn't called quicksilver for nothing.

Elemental mercury isn't poisonous, I know somebody who injected some into his arm to commit suicide and he is still around, however compounds of mercury are so don't heat it up and always wash your hands after use. Keep the mercury in the pendulum and you will be fine.

EDIT: As has been said, pics would be good. I've seen Mercury pendulums in floor standing regulators over here but they are certainly not the norm and as said the pedulums are quite a lump.
 
Last edited:

BOBJAYR

NAWCC Member
Mar 12, 2009
455
3
18
ARIZONA
Country
Thanks very, very, much for both of your comments and advice. I had always
heard it was difficult to work with and you had to be very careful with mercury.

Bob
 

novicetimekeeper

Registered User
Jul 26, 2015
11,178
938
113
Dorset
Country
Region
Thanks very, very, much for both of your comments and advice. I had always
heard it was difficult to work with and you had to be very careful with mercury.

Bob
Using mercury in processes is a problem because it is likely to lead to the release of mercury compunds that might be ingested or inhaled. It can then cause serious illness or death. Clocks and watches were once fire gilded but it led to the premature death of many workers (and to the term lost apprentice, the job was always given to the least able apprentice who didn't then have a long career) It was used in the hat felting business and led to the term mad as a hatter.

In the UK you can't send mercury in the mail, and there was an attempt in the EU to ban it altogether but we have an enormous number of antique barometers in hom,es and traded in the antique trade with associated trades of restoration so an exemption was given to allow that to continue.

Sat in a pendulum in a clock it isn't harming anymody.
 

BOBJAYR

NAWCC Member
Mar 12, 2009
455
3
18
ARIZONA
Country
Attached are photos of the dial and the movement.

Did not get photos of the case. Its a very large, 8' tall
clock.

Have not worked on this type of case and brass plates.

Found in my French clock book a description on dis-assembling
and re-assembling a Morbier clock that has a similar case
and plates.

Any suggestions, cautions, etc on dis-assembling this movement
would be appreciated.

Bob DSC00087.jpg DSC00088.jpg DSC00089.jpg DSC00090.jpg DSC00091.jpg DSC00092.jpg DSC00093.jpg

Bob
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
46,950
1,996
113
North Carolina
Country
Region
That's a Jewelers Regulator. Great clocks, fun to work on and VERY accurate. I don't recall exactly how the movement comes out, but do recollect that the back center wheel pivot is a weak point and usually needs a lot of work. You might even have to replace the pivot.
The movement is fairly simple, one train, and shouldn't cause any major problems to you, other than reluctance to get into it :) It will have a maintaining wheel, in all likelihood.
 

DontheBrewer

Registered User
Dec 12, 2008
7
1
1
USA
Country
Thanks very, very, much for both of your comments and advice. I had always
heard it was difficult to work with and you had to be very careful with mercury.

Bob
Bob - I remember back in High School the teacher had us playing with mercury - with little puddles of it in our hands and sticking our fingers into a beaker of it so illustrate its weight and density - and we are all alive and well. The only warning he gave us was to remove all gold and silver jewelry because the mercury would dissolve the gold and silver. (No personal experience with this).
It seems the greatest risk is ingesting too much orally - such as in contaminated fish. See: Understanding Mercury Poisoning.
Just don't spill the mercury - but if you do, you can usually scoop it up by using a couple of sheets of paper and pouring it back into a container. Most mercury pendulums I've seen are glass vials and one can usually pour the mercury into a jar or beaker for safekeeping.
This all being said; we had a student break a mercury thermometer in a high school; and the environmental authorities evacuated the school and personnel came in with hazmat suits to clean up the microscopic amount that came out of the thermometer. So they do take it seriously.
 

Forum statistics

Threads
167,106
Messages
1,456,194
Members
87,310
Latest member
SuperNeo
Encyclopedia Pages
1,057
Total wiki contributions
2,914
Last edit
E. Howard & Co. by Clint Geller