OXFORDSHIRE BRANCH MEETING, sept 2009
The meeting on the 15th September marked the start of the autumn season and members were advised of the programme ahead up until January 2010, all of which is on the branch website. Members were also advised that entries are now needed for the BRANCH AUCTION which will be held at Steventon Village Hall on the 17 November. Entries to be notified to
Jeremy Barrow introduced the guest speaker, Sid Lines, who had travelled from Kent to be with us. The talk was billed as “ Marble Clock Case Restoration”. Sid had brought along a display of restored clocks which looked resplendent with the high quality re-polishing, as well as samples of work-in–progress and an array of tools and materials.
Sid opened by telling us that he had been an engineer for many years working for a big company and that his horological hobby went back a long way. He not only restores cases but all the mechanical parts as well. Some years ago, his then employer gave him a retraining grant which he invested in the distance learning course and he is now qualified.
The first thing we learned was that these clocks, known as black marble or slate clocks are in fact encased in a form of black limestone. The grey bloom that is found on the surface of the limestone is a natural and unstoppable degrading process. The commercial products offered as “blacking” merely mask the bloom. The only way to get back to the original lustre is to remove the surface and re-polish. Before going into the techniques we were cautioned about health and safety measures needed, as the dusts can be dangerous.
The first thing to do is to dismantle the case taking care to remove the clamping pins/rods and then gently to hammer the parts apart with soft blows to a protected joint, not for the feint hearted. Then all the plaster of paris “glue” has to be scraped off. Broken parts are then re-made from scrap pieces or by cutting out parts of the case which are not seen when re-assembled. The cutting, jointing and finishing is skilled work, all of which we saw on the power point slides.
Gilded or contrast stone inlays often need to be repaired or re-done completely. We saw how the original engraving is reworked with hand made tools and the application of new liquid leaf or gold leaf. A new malachite inlay was also shown.
The polishing is then a labour intensive effort using finer and finer wet and dry papers with scrupulous cleaning in between each paper change. The final polish is with Cerium Oxide applied with a mop or impregnated rotating disc. Re-assembly is with plaster of paris as the glue- never araldite.
Dave Hamer thanked Sid for the insight we were given into this highly skilled aspect of restoration which was very interesting, if a little daunting. Members showed their appreciation in the usual manner