Rivet to welded coversion?

[KRS62]

I am curious if anyone has taken a riveted boat (that needed rib/hull repair) and instead of riveting.....welded it back up? Yes, it seems like a lot more work, but in reality, maybe not so much. It doesn't make sense to proactively do this....but I am in a position on my project boat where I need to remove ribs for repair. So I am thinking should I pull ribs, fill rivet holes in hull, then weld rib back in. Or keep it "simple" and re-revit? (Takes 2 people and air rivet gun + bucking bar.) I now own a TIG machine....and should hopefully have the knowledge to tackle this type of work by years end.

I think this was done on my other boat (the runner, not the project boat.) See the pic. It looks like the ribs have holes for rivets but that it was repaired/welded back in. (Doesn't look factory to me.) I can't tell that this boat was ever a rivet boat. (Duracraft.) It is so old though, I would be surprised if it was welded from factory.

Anyone done this???

KRS

 

[RiverBottomOutdoors]

My guess is that you would get stress cracks around the weld.

 

[KRS62]

That is a good point and yes, there are a few cracked welds in my boat. I do think that the welds look too short though.

 

[bassboy1]

Stick with the rivets.

The problem you are going to run into is distortion. Even the thickest 'off the shelf' riveted tinnies are thinner than the thinnest 'off the shelf' welded hulls. The difference between a .063-.070 thick hull, and a .090-.100 thick hull is drastic. You wouldn't think that .020-.030 will make much of a difference, but it most definitely does when it comes to controlling distortion. Each weld is going to pull just a little bit, and the cumulative effect of that will make a mess when it comes to all the welds on 2 or 3 ribs.

TIG welding that is going to dramatically increase the problem. If one were to attempt that, it is most definitely a job for pulsed MIG, not TIG. You should note that the welds in your photo are MIG (though poorly done), and it's hard to say for sure, but one appears to have already cracked in the heat affected zone, which is highly likely using that joint design (lap joint on structurally unnecessary flange) on that alloy of material (extrusion, giving it an extremely high likelihood of being 6061 or similar).