Re: [VAC] aluminum sheet repair

[Mindy Ward]

try heating the window frame with a small propane torch until it is evenly hot
and when you begin to weld the material should not actually melt- it 
will lose its strength and coiuld become contaminated if it does
also re-heat the frame after welding - the weld and base material 
will  become "elastic" together
also if you grind aluminum welds (unlikle steel)  you remove the 
strength which is all in the structure of the bead