Well here goes... Aluminium frame router design

[njhussey]

Charlie, my welding is the same as yours. I think I've cracked it and then lay a weld that's just attached to one piece...just keep at it. Law of averages means that although you might get through lots of grinding discs you'll get there eventually by having more goid welds than bad ones!!

[mekanik]

I think it would be prudent to do some more test welds, try turning up the amps a bit and try to hold a short arc.
Good luck