Mix the flour, alum and borax in the usual way, to a smooth paste in water, then add the acid and cook in the usual way with hot water.
TO MAKE TENTS, ETC., WEATHERPROOF.
To prevent tents, wagon covers, etc., from rotting dissolve 4 ounces sulphate of zinc in 10 gallons of water, then put in one-fourth pound sal-soda, stir well until dissolved and add one-fourth ounce tartaric acid. Let the cloth lie in this one day and night and hang up to dry. Don’t wring it.
TO PAINT ON CANVAS OR MUSLIN WITHOUT SIZING.
First stretch, then wet the cloth. Wipe off the drops and letter while the cloth is damp with color mixed with japan and turps.
TO PAINT ON ZINC.
A difficulty is often experienced in causing oil colors to adhere to sheet zinc. Boettger recommends the employment of a mordant, so to speak, of the following composition: 1 part of chloride of copper, 1 of nitrate of copper and 1 of sal-ammoniac are to be dissolved in 64 parts of water, to which solution is to be added 1 part of commercial hydrochloric acid. The sheets of zinc are to be brushed over with this liquid, which gives them a deep black color; in the course of 12 to 24 hours they become dry, and to their now dirty gray surface a coat of any oil color will firmly adhere. Some sheets of zinc prepared in this way, and afterwards painted, have been found to withstand all the changes of winter and summer.
PAINTING BLINDS.
When painting a blind never turn it upon edge when cutting in the inside of the rail, because the paint will be likely to run into the pivot-holes and stick the slats. When you set a blind up to dry, set the bottom end up, and be sure to have the slats lie flat side up. Why? Because the bottom end of the blind when hung is more apt to drag on the window sill than the top end is to touch the jam above. If set bottom end up, that end will dry solid and if there are any sags it will be at the top. Keep the slats flat side up to avoid flat edges.