Abstract: A welding apparatus for welding a workpiece includes a welding-containment box of sufficient size to contain the workpiece at a welding position, and a welder disposed within the welding-containment box to be operable on the workpiece at the welding position. A heating apparatus includes four heaters disposed within the welding-containment box. Each heater has a lamp aimed at the welding position, and a heater support upon which the lamp is mounted. The heater support includes a slide that controllably moves the lamp toward and away from the welding position. Each lamp preferably includes a light source having a light output, and a reflector having a reflecting surface disposed to reflect an incident portion of the light output of the light source toward the welding position. The reflector preferably has an aluminum-alloy substrate, and a chromium-reflecting surface contacting the substrate and disposed to reflect an incident portion of the light output of the light source toward the welding position.