Applications of the Silicone Heating Blanket in Violin Making

by George Borun

Originally published in American Lutherie #34, 1993 and Big Red Book of American Lutherie Volume Three, 2004



In American Lutherie #25, Mike Keller describes how he uses silicone heating blankets for bending guitar sides, and mentions an earlier article in Fine Woodworking. The potential of these devices for use in violin making became obvious to me, and with some experimentation and adaptation, I’ve developed specific applications for the violin maker.

Silicone heater blankets, also called flexible heaters, are available from two sources, with a number of standard sizes in stock at each company: Watlow Electric of St. Louis, Missouri (www.watlow.com) and Benchmark Thermal of Grass Valley, California (www.benchmarkthermal.com). Watlow markets through distributors. They have a large selection of stock sizes up to 35" long. Benchmark has a smaller stock size selection, but their prices are considerably lower. They will make any size you wish, but that adds to the cost and delivery time. Stock maximum length is 20", but this is more than long enough for violins. In bending bass ribs, I use two 10" wide blankets for the longer pieces, and only one for the center bout. The best units are 4W/sq.", rather than the 2W models. This type will get up to 500°F in a couple of minutes. Product catalogs are available which list the various sizes.