[EricH]

Originally Posted by Chris is me

Not really, 80/20 weighs almost exactly the same as 1/8" wall 1" square tubing.

And 1/16" wall 1" square tubing is called for.

For the hollow tube in general, you're right. But for the specific hollow tube called for, 80/20 will be heavier.

Comment on the cross-braces: I'm not quite sure I'd trust a 1/16" wall for that application in that pattern. Change the pattern, and you'll probably be fine--but run the analysis just to make sure.