How to Service a Grandfather Clock

The elegant Grandfather Clock has been dutifully standing in hallways, living rooms and public spaces since the late 1600s. Today, we see them as classic and ornate timepieces and find them in the homes of more than just the rich and noble as they were 400 years ago.

Not suited to every house type and certainly no longer made with the same intricacy that they were in their pomp, Grandfather Clocks or Longcase Clocks as you may see them called, are more limited in number than ever. The few high-quality Grandfather Clocks that still exist require careful servicing to ensure they remain running. Of course, you may not own an antique and have purchased a more modern model but inside, the mechanisms have similarities and require a similar degree of attention to have your clock working as well as it should.

At The Clock Clinic, we have been lucky enough to acquire some beautiful Grandfather Clocks, and in this edition of our blog, we show you how you can service yours, so it remains an exquisite timepiece for your family home. A regular service will keep your clock running as it should and help you enjoy its chimes as well as its appearance for years to come.

How does a Grandfather clock work?

There are two types of Grandfather Clock, both offering a very different working to each other. The 30-Hour Clock and the 8-Day Clock. In their prime, one of these clocks stood above the other in terms of signifying your wealth or authority. The 8-Day Clock was seen as the more illustrious variant. However, to ensure appearances were kept, people who could only afford the cheaper alternative would often shop for the editions that demonstrated a false keyhole. A keyhole on the 8-hour clock that was key to its workings. The hope then being that visitors would assume the owner has naturally purchased the more expensive, longer running clock.

The 30-hour clock

The 30-hour longcase clock works using the same mechanics as the Lantern Clock that Grandfather clocks evolved from. Wound by pulling a rope once a day, a weight is lifted that then drives the timekeeping and striking mechanisms. These clocks were also seen listed as 1-day clocks due to the short time between the needed rope pulling to activate the mechanisms. With fewer pieces involved in its construction compared to the 8-Day Clock, it was significantly cheaper than its more prestigious acquaintance.

The 8-Day Clock

The 8-Day Clock is much more mechanical than the 30-Hour version. It works with a key that winds the mechanisms. Two weights were held within, one to drive the pendulum and keep time, the other operating the striking element of the clock.  The striking system used within these was soon adopted across a host of other clocks. Known as the rack and snail, it became a key part of clock-making.

In the early 20th century, the innovation continued, and the now famous chimes were added to the Grandfather Clock. This required the addition of an extra weight, making three rather than two weights necessary. The weight on the left provides the power for the hour-long chimes, the weight on the right doing the quarter-hour chimes and the weight in the middle provides the power for timekeeping. The chimes would sound every fifteen minutes but could be switched off should the noise become distracting or too intrusive.

Before you service your Grandfather Clock

Before you opt to give your Grandfather Clock a service, you should make sure you have the correct equipment for the job! It would be a shame to start working on your clock only to find you don’t have the tools to ensure the job is done as it should be. Gather the following:

  • Gloves -latex gloves are best for metal parts, and cotton gloves are best for wood.
  • The correct oil for your Grandfather Clock. If you have a manual for your clock, this will be indicated within. If not, speak to a specialist who deals in clock repairs to find out which oil is required.
  • Non-abrasive cloth
  • Wax polish
  • Feather duster
  • Ammonia-free cleaner for glass
  • Screwdrivers
  • Pliers
  • Spirit level – To ensure the clock is level and properly balanced.
  • Clock crutch tool - For adjusting the part that connects the escapement to the pendulum.
  • Movement holder – A tool that holds the movement still whilst cleaning
  • Key set- If your clock requires a key for winding. Ensure you have the keys!

In many cases, a full service should be carried out by a professional who has the knowledge and experience of dealing with Grandfather Clocks, however, it can be done at home, if you are careful.

Grandfather clocks are heavy, so should not be moved. If movement is required, it should be done by more than one person. Gloves should also be worn to protect both yourself and the clock itself. The clock should not be laid down either, this can cause damage to the parts inside and may cause damage to the exterior too.

Cleaning and maintaining your Grandfather Clock

Regular cleaning of your Grandfather Clock is vital if you wish to keep it running and looking its best. In addition, a small level of maintenance will also be worthwhile.

Dusting and cleaning the exterior of a Grandfather Clock

Using your feather duster, you can lightly dust the exterior of the clock to remove any light debris. You may wish to also use a non-abrasive cloth should there be any marks on the surface. Make sure the cloth is damp, and not soaked. For the wood, use a wax polish and go with the grain applying the polish with a dry non-abrasive cloth.

For the glass, use the duster first, and then with the ammonia-free cleaner and a dry cloth, clean the glass surfaces. Don’t apply the glass cleaner directly to the glass on the clock. Instead, apply it to the cloth. Then gently clean the surfaces in a horizontal movement.

Lubrication of the Grandfather Clock movements

A Grandfather Clock comprises many moving parts. And for them to be maintained, you may wish to allow a professional to work on it. However, there are a few things you can do.

Before applying any oil to a Grandfather Clock, put on your gloves. Oils from your skin can cause damage to the clock that may not be noticeable at first but could be devastating in the future. You should remove the dial first. This gives you access to the front plate. You should lubricate each part of the clock plate and gears. You’ll see a small dip just outside of the clock plate. This is the oil sink. Fill this halfway with your oil.

Apply the oil to the gears and work through the various areas that require lubricating. There are some Grandfather Clocks that have as many as 35 areas to apply the oil to. None should be missed as each has a vital part to play in the operation of the clock. Any manual for your clock will show the areas requiring oiling.

When oiling the gears always start from the lowest gear, heading to the highest. This should be repeated every two years or when you see the clock is slowing significantly.

It is advised that every 5-6 years, you have a professional check and clean all the movements inside.

Cleaning and adjusting a Grandfather Clock pendulum

You can remove the pendulum weights, batons, and face to give them a quick clean. They should be lightly dusted but not polished. Once cleaned and put back into place, you will want to make sure the pendulum is installed properly so it can keep time. To do this, check the clock is stopped before doing anything else.

You should then adjust what is known as the “bob.” This is the weight at the bottom of the pendulum. Centre this so that the pendulum hangs evenly, not showing a slight bias to one side or the other. With your spirit level, see that your clock is sitting straight. A slight lean to one side or the other can affect the swing significantly. Release the pendulum to monitor the swing, you should see an even swing. If you don’t, the pendulum is unbalanced.

To correct this, you will need to adjust the crutch, this connects the escapement to the pendulum, you may need to bend it a little to adjust its length. This can help correct the swing imbalance. Before testing it again, double-check for any obstructions that may have caused the pendulum to perform incorrectly. Once clear, test again by letting it swing.


Common issues found with Grandfather Clocks

Despite your best efforts to clean and maintain your Grandfather Clock, there can be issues that stop it from working as it should. We have covered some of the more common ones below.

What to do if a Grandfather Clock is running too fast or slow

If your Grandfather Clock is not keeping time properly, you may have an issue with the pendulum.  The length of your pendulum determines the speed the clock runs. If your clock is running slow, you need to move the pendulum up. The shorter the pendulum, the faster it will move. Likewise, if your Grandfather Clock is running too fast, you should lengthen the pendulum to slow it down. This is done by locating the pendulum nut. It should be just above the bob. Turn the nut clockwise to help make the clock run faster and counterclockwise to slow it down. Make sure they are only small movements though, as too much can vastly alter the timekeeping.

What to do if Grandfather Clock chimes are out of synch

By adjusting the pendulum, you should now have the clock operating at the correct speed and telling the right time. The chimes though may be out of sync. To check, count how many times the clock chimes upon the next hour. If they are incorrect, move the hour hand to the number on the dial to match the chimes you counted. The chime count will now be correct, so move the minute hand to the correct time.

Sometimes, the clock may play its quarter-hour sequences in the wrong order for the first hour, but this should correct itself after an hour.

What to do if a Grandfather Clock is not running

If your Grandfather Clock has stopped working, there is a possibility that the clock isn’t sitting level. This would cause the pendulum to either move incorrectly or not move at all. Use your spirit level to check that the clock is level. If it is, you should look to adjust the pendulum or check the dials on the clock face to see if they are damaged. You could also gently push the pendulum to see if it begins to move freely and is not touching the weights or chime rods. If the clock does not make its regular tick-tock after you have swung the pendulum, your clock is out of beat. Simply bend the pendulum crutch a little and your clock should get back to its normal tick-tock pattern.

If the clock is not level, you will find four levellers at the bottom of each corner of the clock, gradually adjust these until your clock is level.


Professional Grandfather Clock maintenance

Many of the tasks listed above are relatively simple to complete, however, with the vast level of moving parts, we know that it can be a little daunting. If you are unsure, you should always speak to an expert horologist for guidance. At The Clock Clinic, for example, we can fully service your Grandfather Clock, including a full strip-down of working parts as well as a clean of the more cosmetic features.

Regular servicing can extend the life of these beautiful clocks significantly, you should dust the external surfaces regularly and look to oil the interior parts every two years. Every 5 years, and in some cases, 10 years, deep cleaning should take place. And this is where you must seek professional guidance. Contact our experts at The Clock Clinic today for a full Grandfather Clock service ensuring you can continue enjoying your clock.

Servicing a Grandfather Clock can be difficult but we can help with a few of the cleaning tasks you can complete at home. Find out more from The Clock Clinic.