Grind a soft base as follows:

48 pounds lithopone of normal composition;

20 "

pure graphite of 85% carbon;

4 "

Indian red of 95% oxide iron;

12 "

bodied linseed oil;

16 "

color grinders' (hard gum) japan;

100 lbs.

Thin this paste, when sufficiently cooled, with 2 gallons hard gum rubbing varnish and 2 gallons pure spirits of turpentine. Result: - 9 gallons of dove gray paint, weighing 14 pounds per gallon, that will permit any good paint applied over it to adhere to the metal indefinitely.