[willy]

Step if they do a weld for you, which is the best way have them do a patch from the inside fist and then weld a bead outside. Got to get a guy who knows what he is doing cause the aluminum is thin and they can make it brittle if done wrong. If he cant get to the inside have him do the exterior bead and seal it and go to the store and pick up an aluminum repair kit, some marine and boat shops have them or order on line. Cut your self an inspection port if you have to and apply the repair kit yourself. Another option is to pick up an epoxy that is compatible with aluminum. scuff up the area good with a scotch brite pad and cut a piece of aluminum to fit and epoxy it in place on the inside after the bead weld.