Pay close attention to the meeting tubes of the bike frame.
which one?
I only see a whole bike with out any details of which weld you worry about.
For welding questions, Best thing to do is take the bike in question
to a qualified welder, and ask them.
someone who lays down a bead TIG aluma-welding, all day long..
out here they make fishing boats for the Ocean of aluminum.
[or steel]