Bear in mind that for repairs as a result of the dreaded Mot mans beady eye it is not acceptable to spot weld the repair , the complete perimeter should be welded.The hole punch was very useful too. On for example, a triumph spitfire, the rear wings met the body via a raised flange, a hole every 2 inches then mig into it on a high setting gave a very tidy looking spot weld needing minimal cleaning up.