Violin Varnish and How to Make It/Chapter 4
CHAPTER IV.
Alcohol.
IN the previous chapters I have dwelt rather emphatically on the superiority of oil varnish as compared with spirit varnish.
However, no work on Varnish would be complete without some reference to alcohol.
Alcohol is a produce composed of carbon, hydrogen and oxygen; it is usually diluted with water in various quantities, by which its strength is determined.
Alcohol is or can be extracted from an innumerable variety of materials, in fact, anything containing sugar in any proportion can, by the process of fermentation, be used for the production.
The materials most usually employed are wines, roots, seed, etc. Alcohol is seldom obtained pure for numerous reasons, the principal being that it absorbs with great avidity the moisture contained in the atmosphere. It also contains a proportion of essential oils.
The chief characteristics of alcohol, when pure, are its powerful, pungent odour, and its caustic action on organic tissue.
It is a very volatile liquid, and colourless in appearance.
It readily dissolves such substances as rosins, gums, etc. Hence it is extensively employed in the manufacture of varnish.
The great number of uses industry now make of alcohol has enabled the manufacturer to produce alcohol on a large scale.
Owing to the prohibitive price reached by spirits of wine, scientific research was brought to bear on the subject, and many discoveries were made, by which alcohol is now no longer extracted exclusively from spirits of wine. The most usual substitute to spirit of wine is wood, from which methylated spirit is extracted. This spirit of wood (methylated), when of good quality, is often used by varnish makers, although it contains, in common with all other spirits, a certain amount of essential oils, ether, and other alcohols.
It is therefore advisable, when using alcohol, to procure the best quality obtainable, and if necessary as a precaution, to purify it further by the extraction of as much of the moisture and essential oils as possible.