I would agree except that I've repaired many corroded items and found that the corrosion is usually distributed around the area where you find a hole. So even if you open it up there will usually be section of very thin metal all around the hole making it difficult to get a good weld. For this reason I always try and put my weld (metal plate) as far from the hole as possible....that said, if the surrounding metal is solid then spot welding is the best course of action!!
