Practical House, Wagon and Automobile Painter / including sign painting, and valuable hints and recipes

by W. F. White

FLUORIC ACID, TO MAKE FOR ETCHING PURPOSES.

You can make your own fluoric acid (sometimes called hydrofluoric) by getting the fluor spar, pulverizing it and putting as much of it into sulphuric acid as the acid will cut or dissolve.

Druggists through the country do not keep this acid generally, but they can get it in the principal cities. One ounce will do at least fifty dollars worth of work. It is put in gutta percha bottles or lead bottles, and must be kept in them when not in use, having corks of the same material. Glass, of course, will not hold it, as it dissolves the glass, otherwise it would not etch upon it.