Ok, that was to be expected for the good reasons that I am an unexperienced welder and that I try to build an intended wooden boat in aluminum 😎 but hey, would Columbus ever had discovered Turtle Island without trying "something else"?
In fact there is so much to tell that I don’t know where to start. All metals including aluminum deforms when heated. They tell you a very limited amount about it during welding classes, nothing about the size of a boat. So I have to learn my lessons during building-time and I can tell you: these lessons are very very interesting. I already experienced these phenomena with the centerboard-trunk but after that every weld caused its troubles. It troubled me a lot. Did I choose the right welding method? Did I really bought the wrong welding machine? Did I really do the wrong welding course?
Now a few weeks later I know the answer and of course as ever it is “yes and no”.
Why do most of the aluminum boat builders use the MIG welding process? Not because of the advantages of TIG but of the disadvantages ofcourse. First of all and most im portant the heath transfer. TIG is a slower process and adds more heath into the metal than MIG. The difference is not only significant but humendous (as I experienced). Second - I thought not very important - is that MIG welds with only one hand. In fact this has two important advantages: first you can hold the pieces into place while (tack)welding with the other hand. Turned out to be very very very handy. And second the “agility”. Single hand welding also means welding in narrow spaces, easy welding in all positions and welding left and right handed!
You guessed already I had to switch to MIG. Fortunately I could sell my TIG welder fast and for a good price and found a MIG welder with the right specs by my favorite supplier (HBM-machines).
Yep this is a professional machine and it’s about the same price as my TIG welder.
Now what about lessons? MIG is completely different from TIG welding. Aluminum-welding is aluminum-welding however. The metal behaves about the same. And the difference between no welding experience at all and some experience is much bigger than than the difference between TIG and MIG. They say that if you start with TIG (as the most difficult proces) you can learn MIG faster and I think that’s true.
