Last week I had two dings repaired: one in the roof, the other one in the door. Very interesting technique: they set-up a heat gun about a foot away to soften the paint, then accessed the inside of the dent with a long tool: a rod with a handle and a curved, ball end shaped bar at the end. The handle can be rotated and then locked. The tool is inserted thru a convenient opening, in case of the door, between the glass and the skin using a small wedge to hold the access open. A light, about a foot long and 8 inches wide with three lamps is attached with a magnet and positioned conveniently. You can see very clearly the tool pushing on the dent from the inside. The dent is carefully pushed out until it is a little higher than the surrounding sheet metal. Sometimes a hole must be drilled for access for the tool such as under an installed light fixture. The hole is later closed with a plastic plug and never visible because the light fixture is covering it. By twisting the handle and resting the rod against some structure, good leverage can be had and it is easy to push the metal out. The metal of the body is very thin, I measured less than one millimeter, and very ductile. When there are no more hollow spots in the surface, a steel punch with an almost flat surface about the size of a quarter is used to hammer on the raised parts, but not by hammering with the punch, but by hitting the punch with a hammer or even only with the handle of a hammer, very carefully. It takes practice, but the light helps because by looking at the reflection, one can see even the slightest irregularity. In the end, the area is buffed using a disk grinder with a polishing wheel. The result is astounding: The dent has completely disappeared. It takes time and patience and to make a profit it must be quoted right: In my case the ding in the door was quoted at $375 and the one in the roof $400 and it took one man three hours for both.
