I just got my new Lincoln 185 TIG welder, I haven't tried aluminum yet. How is the 13b manifold material to weld?

Easy if you're any good :-)  

The hardest thing I've had to weld was a thin (maybe .063) aluminum tube to a thick (1/2" or so) piece of manifold.  It was impossible to keep from blowing through the relatively thin tubing.  Eventually, I got it, but it was ugly.  I had to re-do that later, and did some milling and grinding on the manifold to make sure the area I was welding was only about 1/8" thick.  That helped a lot, and I wasn't too embarrassed by the results.  I'm under the impression that a real welder wouldn't have had any problems with this at all. 

I've probably done more aluminum than anything, but I've done a few pieces of mild steel, and all the exhaust, which is 321 stainless.  Everything is easier than aluminum, but at least it's doable for the average person with TIG, and some practice.  

Cheers,

Rusty (delaying the inevitable even longer)