Repairing aluminium casting

[Cofe]

Re: Repairing aluminium casting

And if you fail to do a good job with the brazing rod, you have the zinc from the rod all over the place so a real welder may not be able to repair it with a TIG.

I agree with Bruce58 about trying to TIG weld something that was botch welded with OX/ACE aluminum rod. A big problem with using OX/ACE on aluminum is that carbon is introduced with the carbonized flame from the torch and combines with the molten filler material and base material resulting in a weak weld zone. Extra grinding is necessary to remove all of the carbonized material before TIG welding, or you will end up with porosity, and a weak weld zone.