We frequently see clock owners who tell us that their clock has been running perfectly for twenty years ! They then go on to suggest that for this reason there can’t really be all that much wrong with it, can there ?
The answer to that question can be summed up in more or less one word, “FRICTION”.
Perpetual motion has continued to elude us because of two things that we can’t quite really overcome, however hard we try to defeat them . Gravity and friction !
In the case of mechanical clocks, the principle enemy is FRICTION, caused by the interaction of two surfaces which rub or slide against each other. In a new or freshly restored clock nearly all of the various moving parts, steel against brass and steel against steel, have the friction between them dramatically reduced by being burnished, spotlessly cleaned, and then oiled with fresh clean oil of a suitable type and in an appropriate quantity.
Unfortunately it is this very oil which also becomes the enemy. Over a period of time, the oil degrades, evaporates, and becomes dry and hard. In this condition in many parts of the clock (pivot holes in the plates mainly) the oil then picks up contaminants (minute particles of grit and dirt from the environment) and instead of assisting the free movement of the parts by lubrication, now performs exactly the opposite role and increases friction on those parts, retarding the movement and acting as an abrasive rather than a lubricant.
The result of this in a clock, after some years of running on degraded oil, is grooves worn into pivots (the end of the shafts which run between the two plates), grooves worn into pinions (the small cogs driven by the wheels) and grooves worn into the steel acting surfaces of the escape pallets. The deeper these grooves become, the greater the increase in friction, and finally of course the clock will stop. The driving weight or spring (the latter itself often with its coils stuck together by dry oil) is no longer able to overcome the hugely increased frictional forces in the machine.
A good restorer carefully dismantles the entire clock, every single part. Examines everything for signs of wear. Thoroughly cleans all of the parts and then examines everything again, noting all of the various parts which have been damaged. Pivots are carefully burnished, pivot holes which have become oval instead of round are re-bushed, escape pallets are often re-surfaced and then carefully polished. All surfaces which act against each other are carefully cleaned and then finally the clock is re-assembled and carefully oiled with a high quality (often state of the art) clock oil. Occassionally the wear to both pinions and wheels is so severe that some of these have to be carefully re-made. Re-made to precise tolerances and in a style commensurate with the age and type of the clock.
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