FIRST: DO NOT WELD ON ANY STRUCTURAL ALUMINUM PART, ESPECIALLY SOMETHING AS IMPORTANT AS A RUDDER BELLCRANK, WHICH IS 2024T3 ALLOY. 2024T3 IS NOT ONE OF THE ALLOYS THAT WELDS VERY GOOD. SPOT WELDING UNDER CONTROLLED CONDITIONS IS THE ONLY METHOD OF WELDING FOR THIS ALLOY.
We ordered a product called Alumi-Pro through JC Whitney, manufactured by BAC Industries, Hopkins, MN. The info on the packaging does not indicate what alloy the aluminum welding rods are, nor does it indicate what alloys it works best with. However, we ordered it for experimenting to determine if we could use it in certain applications. We've welded 6061, 5052 with excellent results. We also welded 2024, just to see, with excellent results, although I would never use it in a structural application. I did a conductivity test with eddy current, which tells me if the temper/hardness has changed due to the heat. I only get a different reading right at the weld, which could/would also indicate that the welding rod is a different alloy/temper. My test did not show any remarkable change in temper of the base material, and destructive testing
proved the weld was exceptionally strong, not brittle. The process is much like brazing or soldering with a propane torch, or acetyline. I can see this being very useful for cowlings, nose bugs, wing tips, wheel pants, etc.