I purchased a metal cutting chop saw from Northern Tool. Brought it home and gave it a try. I guess it has special carbide teeth. It cut through the aluminum tube like butter. Yippee!
The chop saw allowd me to cut off nice, 1" long pieces, but I could not set it up to cut the square piece into two pieces to fashion the clamps.
Guess I need a band saw. I will start looking into that.