Aluminium Welding

Last time I tried aluminium welding the results weren't great. I had run out of argon -- the next day I had no argon at all. The valve on these disposable cylinders is held closed by the pressure inside, so once you go below a certain pressure the rest leaks out very quickly. I'm not sure if such cylinders should be considered one use, but I'm going to do my welding ASAP. I should have got the full size refillable bottle with a proper valve.

The photo above of my first attempt welding aluminium under reasonable conditions. I welded some plate I had to part of the bell housing I cut off. It doesn't feel very different from regular steel welding. You'll notice that the left hand end doesn't look so great. I'm blaming this on the lack of argon flow after finishing the weld -- the metal is still molten and the argon is no longer protecting it from the air. My welder has a "Burn Back" feature but I'm not sure if it can be abused to keep the flow going after the weld has finished -- it stops the wire feed but doesn't turn off the current, burning back the wire to prevent it sticking to the weld. If I turn that up to keep the gas flowing for longer, the arc will burn further up the wire. Maybe it will burn out before the torch, or maybe the torch itself will sustain the arc. We shall see.

Next up I have to make a template for the motor mounting plate, acquire the aluminium and have it water jet cut. I'll try to break my weld and see how good it really is, but I'm fairly confidant I can weld the plate into the gearbox.