Welding aluminum

[Tim9]

I could see the MIG gun making holes/pits in the aluminum and filling them with steel. You might get a mechanical bond that way that would be hard to pull apart.
Robert

Yeah...might be hard to "pull apart".... But Id hate to be behind the boat trailer where the bozo used some aluminum pieces because he ran out of steel angle iron.

And JW...Im happy to hear that you were just commenting on some photos. FWIW...Im surely no expert. And welding technology is always advancing. So I guess I should never say never. That said, Ive always felt that aluminum and steel don't mix well. Not even when bolted for that matter since the galvanic nature of the corrosion.

 

[whitmore]

If one DOES want to join aluminum and steel, there's that zinc-based aluminum
solder to consider; it flows at propane-torch temperatures, and works adequately
on very clean aluminum, as well as steel, and galvanized steel (without any
need to remove the galvanizing). Not really a good structural weld, of course.

 

[Tim9]

I’ve never tried those muggy weld zinc based sticks but I’ve read quite a number of positive comments about them. And other companies now sell them so there’s probably a decent market for them. And if it didn’t work, I doubt that there would be a market for them.
On a side note, I ran across this the other day on YouTube. Jody on welding tips and tricks used aluminum arch welding sticks and dc Tig and it looks like it worked okay. Not pretty, but decent penetration. Really a neat trick. And FWIW, I’m pretty sure he’s using Argon gas…. Dc Tig…. And 3/32 aluminum arch welding sticks as the filler.
DC Tig aluminum and arch aluminum stick weld.