"When your hand falls off," he advises, humorous but not entirely joking, "switch. It's an advantage to be as ambidextrous as possible. They're--" he pauses. "Not in the rack because I haven't made one yet," he finishes, and then points to a row of sharpness in various shades of metal and silicate, laid out carefully on a rough workbench in a corner along with an assortment of other handled tools.