1988
AL#14 p.56   BRB2 p.76            
Jonathon Peterson                                                                                           

▪ Peterson finds a relatively safe method of sharpening files by acid etching. THE ORIGINAL PUBLICATION OF THIS ARTICLE CONTAINED A SERIOUS ERROR. ACID SHOULD ALWAYS BE ADDED TO WATER, NOT THE OTHER WAY AROUND. THIS ERROR HAS BEEN CORRECTED IN THE REPRINTS).