I was wondering how some of you guys confirm that you are getting good penetration on aluminum tig welds. I was taught in tech school to weld one side of a t-joint, then stick it in a vice and hammer it apart and see if you are melting the edge of your verticle piece. Does anyone else do this, or how do you check it? It's pretty easy to see if the edge is fused but some times when I break them apart the weld doesn't budge and the aluminum square tube shears above the weld.