Enerjoy IR heaters. These panels are amazing! Look like drywall with acoustical spray on them and extruded metal edges. Super effecient, very little power draw. Designed by a (I think a) MIT Prof for homes that run on solar power or windmills so draw had to be low. They do not glow, no flame. IR heats objects (people, tools, parts) by vibrating molecules so you do not heat the air, the warmed objects can eventually heat the air. Electric powered, heat in about 5 min, so fast.
The company has a "Woodshop Series" - cosmetic damage. When I got mine some had really minor defects, other little bigger, some I could find nothing wrong. Result is something like 40% off for the defects makes them the woodshop series.
http://www.sshcinc.com/woodshopseries.htm
Several different sizes, wattage, dimensions, voltage. Send your info they will design for free and give a parts list.
Good old article about them from Fine Woodworking Magazine:
http://www.sshcinc.com/FineWoodworking.pdf
I have separate thermostats in my metal/autoshop, woodshop and "paint room". Paint room is like a clean room, 8' x 8' and in there I'll set thermo to 90° to cure fast and small space so not much cost for electricity.
