Antique clocks in good condition need very little maintenance and any servicing or restoration should only be entrusted to a qualified horologist, clock maker or restorer. LAPADA can put you in touch with professional dealers near you who can advise you. Ensure that the surface on which a clock is placed is perfectly level. If it is not it will, most probably, affect the running of the clock.
Clocks are either spring driven or weight driven and with either type they keep time better if they are kept running. Regular winding is essential, using only the correct size of key. It is helpful either to label the key or keep it under the relevant clock. Great care should be taken when winding.
For spring-driven clocks, steady the clock with one hand and wind in a slow, deliberate manner by a set number of turns - usually six to eight complete turns will fully wind the spring, although on some clocks a 'stop' limits the number of turns to four or five and prevents over winding. It is always better to under wind than over wind. An 8-day clock should be wound on the same day each week and if there are separate winding holes for chimes or a striking chain, wind these at the same time.
Regular winding of weight-driven clocks is not so important for timekeeping as the weights give constant power to the movement but it is best to stop the clock rather than let it wind down as the movement can be damaged if the pendulum swings with no power. Open the door to enable you to see that the weights do not foul the case or pendulum and wind until the pulley touches the seaboard (the board on which the movement sits). As the weight nears the top go slowly to ensure it does not bang against the seaboard. To set the hands to the right time,move only the minute hand by gently pushing it with your finger in a forward or clockwise direction. Never move the hand anti-clockwise. If the clock strikes or chimes, do not move the hand on until it has finished striking.
A pendulum clock goes faster or slower depending on the length of the pendulum. Shortening it makes the clock run faster and vice-versa and the length can be changed by moving the bob at the end. Usually there is a nut for fine adjustment below the bob but sometimes it is in the middle or above it. Turn the nut to the left and the clock will run slower, to the right and it will run faster. If this does not make the clock keep time it probably needs a professional clean. Some pendulum clocks, particularly French ones, are regulated by a small watch key through an area on the dial. Turn the key clockwise to make the clock run faster and anticlockwise to reduce speed. Some clocks have a lever at the back which can be moved to the left or right to regulate the clock, the lever often being marked with a + or - to indicate faster or slower. Clocks with a platform escapement and no pendulum should be regulated by a clockmaker or restorer.
Most clocks should be moved as little as possible and only when absolutely necessary as the mechanism can be disturbed and sometimes need professional attention before they will run well again.Do not move antique clocks with a pendulum to dust underneath them; rather remove the dust with a thin brush. Do not lift a clock by its handles which are more for decoration than practical use, but support it from underneath. Clocks with no weights such as spring driven clocks can be moved without damaging the movement, but should still be carried carefully.
Weight driven clocks should be allowed to completely run down before moving them. Clocks with pendulums must have the pendulum tied down or removed when the clock is carried so it does not swing and longcase clocks should also have the movement removed from the case. This should be done very carefully, perhaps with the help of a professional in order to avoid expensive damage, and when setting up clocks or getting them 'in beat' it may be advisable to get a clockmaker or restorer to help.
Clock movements should not be cleaned or oiled at home as the movement needs to be taken apart to do the job properly. Never spray a clock movement with spray can oils such as WD40 as these get into areas which should not be lubricated. Too much oil causes dirt and grime to collect which make moving parts abrasive and will affect the accuracy of the clock. Dust the case with a soft duster or very soft artist's or photographer's brush. Hold the clock steady and be careful not to let loose veneer, moulding or other decoration catch on the duster. If any pieces become loose, keep them in a labelled envelope for a professional restorer to replace. Do not clean the glass of a clock case with a commercial glass cleaner as the chemicals may harm the surrounding metal or wood. Polish instead with a clean, dry, soft chamois leather and for stubborn marks, use a swab of cotton wool dampened with a mild detergent solution in warm water or methylated spirit. Wipe clean with cotton wool dampened in clean water and gently dry with chamois leather. Be very careful not to allow fluid to touch the surround or run into the movement.
Metal skeleton clocks should only be cleaned by a restorer and never be lacquered or polished with a metal polish, which should not be used on brass carriage clocks either. Dials (the clock face) should only be cleaned by professional restorers. The silver will come off if silvered dials are cleaned; the numerals or any writing can easily come off a dial, especially if it is enamelled, and enamel is very easily chipped or broken; painted dials need a dial or painting restorer and paper dials are very fragile. If a dial is very dirty it probably means that the movement is too and it would be best to have the whole clock cleaned by a professional restorer. Clock cases are made of a wide variety of materials including wood, marble, glass, alabaster, ceramic, tortoiseshell, metal and plastic and should be cared for in the same way as a piece of furniture or an object made from the same material. However the care of a clock case must take into account the protection of the movement.
Clocks should be stored in a cool, clean, dry and dust-free area, not in a damp basement or loft. Take account of the materials of which the case is made and store the clock in conditions best suited to the most vulnerable material. Keep loose pieces such as weights, pendulums and keys with the clock, or clearly labelled as to which clock they belong. Remove batteries from electric clocks and store them away from the clock as they can leak and cause damage.
Thank you to Gavin Douglas for the images