|
My Works |
|
|
|
|
|
|
|
|
|
|
Surface finishings have changed drastically in the present century. However regarding "antique" furniture we must think about three kinds of materials: Varnishes based in shellac. Varnishes based in copal resin. Wax. The first kind are finishings that are more or less based in a resin called shellac, product of the secretions of an hemipter insect called Coccus Laca, from the south of Asia, specially India. There are several kinds of shellac, mostly as a result of its processing. Presently the most common is the orange colored, sold in thin and little scales. It is dissolved in ethanol or methanol indistinctly. The most commonly used is methanol, but not necessarily the best procedure.. A rule of thumb in the preparation is to put a certain amount of shellac in a glass flask and then alcohol so as to cover it and "a little more". The solution must have a viscosity between water and milk to begin the process called "French polishing". This is a method of applying the shellac by means of a small piece of cotton wrapped in a thin, dust- free, non- fibrous cotton fabric. The solution is poured in a little amount at a time in the inside of the cotton and applied over the wood by means of a circular, non-stopping motion and a progressively more diluted solution, with the aggregate of little "touches" of pumice stone in powder as a filler of wood and vaseline as lubricant. The dilution and continuous rubbing has the effect of flattening the surface and giving, in the final steps when only alcohol is used, an incredible shine, impossible to obtain with other methods. Shellac has also reflecting and absolutely different tactile properties from other kinds of finishings. Shellac, at least when new, is identifiable without doubt:: something between oily-glass and silky. Conservation and restoration of this finishing presents many problems as shellac is extremely sensitive to water and alcohol (drinks and beverages). Therefore, valuable furniture with this kind of surface must not be used in daily living or similar situation. Being properly used, shellac finishing doesn't need special care, apart from being dusted and, in certain objects, carefully and conservatively rubbed with a microcristalline wax, and avoiding direct exposure to sun light. The restoration of shellac can be performed in two ways: its complete removal and remaking when deterioration is so extensive that seriously compromises the aesthetic carachteristics of the wood under it, or a careful cleaning and partial "remaking" of the finishing. The first process must be considered carefully taking into account the risk of destruction of deliberate staining or shading and\or natural darkening and other changes in the wood. It is strongly advised that this procedure (the complete removal) be made by an expert restorer and with methods that preserve the changes suffered by the object along its history (if they don't seriously compromise its aesthetic unity). |
1999 Darius Gubala