Gumming a band saw

Gumming of a band saw

Gumming is the process of grinding the gullets of the saw teeth to a particular shape. The saw filer uses a semi-automatic grinding machine for this. Band saws operate under high stress and heat and in the presence of wood chips. In doing so, carbon migrates into the steel from the wood. Gumming will prevent case hardening and fatigue cracking of the band saw gullets. Resaw Band saws (teeth on one side only) may be left or right handed, depending on which way the teeth are pointing and which way the plank falls from the log when cutting. Double cut saws (teeth on both sides) are always gummed right hand teeth first.

For proper saw operation and wood chip removal, a tooth profile of the gullet is needed. This information is needed for the ease of gumming a saw. The shape is determined by the type of wood and cutting conditions. By manually shaping the grinding wheel with an abrasive brick, and setting up the of his grinding machine, a saw filer can maintain the the shape of the gullet. Variations may include the face angle, face length, back angle, gullet width and depth, and a frost notch (if necessary). Typically, band saw tooth dimensions are 1-3/4" tooth space x 3/4" gullet depth x 3/4" gullet width (grinding wheel width) x 30deg face angle x 16deg back angle.