I realized that I was going to need a lot more training to make model proper welds. I took last day to try various methods and these are what I came up with so far:

1. I like the one joining the two spheres the most, mainly because it’s concave and has circle “kind of circular” weld marks (or it could be a big glob of bondo…).
2. The tube weld is probably more realistic in term of the amount of material it’s actually using, it’s a little too straight but it should do the job too.
3. The straight weld… kind of sucks, but it’s the one I will use the most I’m afraid, I tried to make it slightly concave too, but the circular weld marks are not very convincing. (Also way too much material obviously)