Types of Wood Varnish, Varnishes

¶ The purposes served by the use of varnish are quite obvious. First, it is needed to protect surfaces from moisture which will warp, swell and raise the grain of the wood and from gases ever present in the air which discolor wood not protected. Varnish also protects stained colors from light and air which fade them, especially the oil and spirit anilines which must be covered immediately if they are to hold their color a reasonable length of time. Varnish protects wood from wear by surface abrasion to some extent.

¶ Decoration produced by varnishes is just as important a purpose served as the protection of the wood, decoration in the form of beautiful polished gloss or the alluring charm of the dull lustre finishes. Varnish increases and enhances the brilliancy of colors as well as to preserve them from fading.

¶ What varnish is may well be considered for a paragraph or so. The word has taken on a broad meaning with its years of use. It does not mean any one definite composition, but rather includes many compositions within its meaning. A general definition may state that varnish is any liquid, containing no pigment, which is used for protection and decoration of surfaces, one that can be spread in a thin, homogeneous film and which will dry to a hard, transparent or semi-transparent coating. A chemist would describe varnish something like this,a liquid which usually is transparent, but sometimes translucent, one which when spread in a thin film on a surface dries by oxidation and by evaporation of its volatile fluid content. It may dry with a high gloss or with a dull lustre.

¶ Kinds of varnish are very numerous. The larger varnish factories offer in their sales lists between one and two hundred kinds. Many industries require a large number of varnishes of regular and special kinds and they are used for many purposes in addition to protection of surfaces from decay and corrosion and for decorative purposes. For instance, the harness on the looms of cotton mills and even bobbins of the mill machinery are varnished to reduce friction. But the varnishes in which the wood finisher is interested are limited to the architectural class described in the following pages. There are only three major classifications (1) Oil Varnishes ; (2) Spirit Varnishes ; (3) Japans.