This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
(see also Brushes and Paints)
The cleaning of the brushes and vessels in which the varnish or oil paint had dried is usually done by boiling with soda solution. This frequently spoils the brushes or cracks the vessels if of glass; besides, the process is rather slow and dirty. A much more suitable remedy is amyl acetate, which is a liquid with a pleasant odor of fruit drops, used mainly for dissolving and cementing celluloid. If amyl acetate is poured over a paint brush the varnish or hardened paint dissolves almost immediately and the brush is again rendered serviceable at once. If necessary, the process is repeated. For cleaning vessels shake the liquid about in them, which softens the paint so that it can be readily removed with paper. In this manner much labor can be saved. The amyl acetate can be easily removed from the brushes, etc., by alcohol or oil of turpentine.
Dissolve 20 parts of caustic soda (98 per cent) in 100 parts of water, mix the solution with 20 parts of mineral oil, and stir in a kettle provided with a mechanical stirrer, until the emulsion is complete. Now add, with stirring, 20 parts of sawdust and pass the whole through a paint mill to obtain a uniform intermixture. Apply the paste moist.
To remove old varnish from metals, it suffices to dip the articles in equal parts of ammonia and alcohol (95 per cent).
Pour olive oil into a dish and scrape a little white wax into it. This mixture should be heated until the wax melts and rubbed sparingly on the stains. Finally, rub the surface with a linen rag until it is restored to brilliancy.