Brazing Aluminum, welding it with a TIG... Biggest plus is if you can get the pieces very clean before you start. I use a local bought aluminum cleaner, that is originally for cleaning aluminum wheels, but works great for that. I can weld... BUT-- I never got a bond I was really satisfied with by brazing with HF brazing rod. Maybe that might be because I have lots of other ways that I know are stronger?
Next is if you are doing TIG, then make sure you're using an AC TIG (Most are DC). An AC wave form will push through the surface, pushing through the oxidation that forms as the aluminum surface heats up.
There is aluminum stick rod, but that really takes a lot of practice to get a good strong weld.
What I've found the easiest is actually just using a MIG welder and either ARGON or an ARGON mix for Aluminum. The controlled feed rate of the wire helps keep a consistent bead going. "High-end" MIG welders alter the wave form and add a push/pull to the wire feed action to create an even better bead for aluminum.
That leaning curve on TIG welding aluminum is that there is almost no warning between not melted and the sudden pool of molten aluminum. It's not like you see anything "glowing" beforehand, like with ferrous metals... It just starts to look "wet". Anyway you go, there's a learning curve with it.
I know- right? I know way too much about that because of having to do fabrication and repair on heavy equipment and heavy trucks. Remember, I'm also a BlackSmith. Plus, along the way, I had bought a bunch of welding and cutting equipment so I would have something to do when I retired. (Metal Art)
"Don't worry, I saw this work in a cartoon once."
"Usually learning skills and tooling involves a progression of logical steps."
Last edited by MAFoElffen; 02-12-2014 at 12:57 AM.