Welding on dented matetial?????

[THEMOORINGMAN]

Hi,

I have to have a small spot welded that's on a nice base ball size dent like the boat took a line drive hit. 1/4 hull on the bottom.

Are there any warnings I need to know because the welding will be on this dented, stretched and deformed aluminum?

[kmorin]

mooring, if the spot is at the 'top' of the dome of the dent then there's a possibility its at the location of a 'spider web' type of elongation crack? If that is true then the weld could reveal a series of cracks running in different directions from some single focal point.

That can be a problem is the cracks are close together and don't shown on the surface, yet. Sometimes as aluminum reaches its failure point in elongation, it will tear or crack in different directions that don't completely fail or come apart, but they are still thin failure lines. If these fill will water and its retained; welding will be explosive when that turns to steam so preheating is not unreasonable, and welding with TIG is preferred due to the increased control.

If the dent or cup in the hull is near a structural weld inside the boat (?) there is also the potential problem that there is some tearing near the toe of the weld inside the hull and that may not shown on the surface very well either, if the bent up metal is near these welds because the metal can be compressed onto the weld area. So welding there can be a problem (MIG) as the previous weld can hold gas impurities that may now hold water or bilge contaminants and need to be gouged out with carbide burr to make sure the weld is on clean metal edges.

pictures sure make this type of reply less generic.

Cheers,
Kevin Morin
Kenai, AK

[THEMOORINGMAN]

Ya, I figured a simple "have at it, not problems" was not in my future.

It's not near anything structural or any other welds. The dent has been there for years and years and the only real dent in the boat. Maybe a hole saw, a big bag of $, and a welder will make this problem go away!

[kmorin]

If its not cracked and leaking why bother?

cheers,
Kevin Morin
Kenai, AK

[THEMOORINGMAN]

I just figured I would keep up on things and winter is coming so its a good time to fix things. Its definitely not leaking and took one ocean hell ride this year........no leaks!

[THEMOORINGMAN]

I just took some pics of the dent / mark and it's smaller than I though. Maybe ping pong ball size.......false alarm. Sorry.