An old sawyer at a lumber mill where I worked in the ’60s used this simple trick to clean gum and pitch off blades. Ammonia! Yup, just soak the blade or bit for about 1/2 hour or longer in a pan of ammonia and, Voila, Presto-cleano, completely clean! A light scrub with a 3m pad, rinse with water and dry. Make sure you do this outside or in a well ventilated area.
