I've got an accessory for my air hammer that puts a stepped-down flange on the edge of a hole. This allows a flush patch to overlap the hole and provides a much stronger method of installing it than a simple butt weld.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!