The FAA allows gas(oxy aceleteneSP?) welding to be used in repairing chromemoly in airplanes, seen it done on a Taylor Craft and a early Piper Most of the newer spam cans are all rivited aluminum monoque construction except for the wing spars, landing gear and motor mount cages A lot of the earlier airplanes that where fabric covered where wood and steel tubing combined or all of one or the other