it can be done i have done it several times with a tig but the weld is very brittle........use 2% thoriated tungsten .....pure tung will just melt away
Been welding aluminum for years......use pure tungsten ..........obviously someone has been reading a little to much....2% thoriated will last longer but is generally used for stainless.....and when you grind it wear protective gear because it is radioactive.......the choices you have made are...
when welding cast you have to heat and test with a temp stick.....around 500 degrees.........use nicad or 7018 stick......or braze.....mig won't cut it......