Spreading Shellac when Woodworking

Spreading shellac is one of the very most difficult operations the wood finisher is called upon to perform. The alcohol in the mixture evaporates so rapidly from a shellac film that it is almost impossible to avoid laps, streaks, and untouched spots unless one has had considerable skill and experience.

As a transparent filler or surfacer on woods without open pores, there is no other finishing material equal to denatured alcohol white shellac. When applied as a first coat to size wood, it is wise to dilute liquid shellac of ordinary strength, such as a mixture of four pounds of gum to the gallon of alcohol, by using about one-half alcohol and one-half liquid shellac.

Two coats of thin shellac, with a slight sanding between the applications, will make a much better finish than one heavy coat, chiefly because it is much easier to spread thin shellac evenly, and also because of the greater probability of covering every portion of the surface by going over it twice with a brush.

Shellac must be applied to wood with great speed by the use of a wet brush and spread lengthwise of the grain. The operator should stand in a position from which he can see just what he is doing, thus avoiding laps, streaks, and uncovered places. Frequently, it is possible to place the object between the finisher and the light by shifting it into such a position that the freshly covered surface will show a bright gloss where it has been shellacked.

Every portion of the surface should be covered with the brush while the coat is being put on, for after about one-half minute no touching up can be done satisfactorily. Attempts to retouch tacky shellac often cause trouble, as rough places will result which generally harm the finish more than uncovered spots do because these small areas will be covered over by later coats of finish and usually do not show unless an effort is made to repair them after the film has partially set.

Two coats of thin shellac will make a better finish than one heavy coat, because it is much easier to spread thin shellac evenly, and because of the greater probability of covering every portion of the surface by going over it twice with a brush.