Cellulose undercoats are made on a special oil base and require from eight to twelve hours to dry, after which they are sandpapered smooth. The usual colours for undercoats-are white, grey and buff colour, and any of the cellulose enamels will cover solid in one coat over them.
Undercoats cover from 8 to 10 square yards per pint on bare wood, slightly more on metal and non-absorbent surfaces.
The cellulose enamels are supplied in small tins of no definite measure at a moderate cost, and also in and 1-pint tins, which is the best way to buy them. A large range of colours is available, and with most brands these can be intermixed to form additional shades. Clear lacquer for finishing wood in place of French polish is also available, as well as stain lacquers. With the colours it is most important that the contents of the tins be thoroughly stirred before use as, with storage, the pigments settle to the bottom and insufficient stirring will not produce the correct shade, nor will the enamel cover solid.
Brushing cellulose lacquers and enamels are not suitable for surfaces that will be exposed to the weather. Special thinners are necessary for cellulose paints, and whilst it is seldom necessary to thin the paint, some thinners should always be available for washing out brushes, cleaning the hands, etc., as turpentine and linseed oil will not dissolve the paint. Cellulose paints and enamels are highly inflammable, and the same care should be taken with regard to their use and storage as is accorded to petrol and benzine.