Re: water in pontoon
What he said.... If it were me, I'd get it fixed professionally.
I did a little bit of TIG welding and aluminum brazing many years ago and the one thing that sticks out in my memory is the weld has to be really, really clean. Brazing aluminum was a real nightmare.
I've toyed with the idea of taking a welding refresher class at the local career center just 'cuz I like that stuff. Might come in handy with my pontoon.
No man can have too many tools now can he?