Aluminium Cat track thickness

[falls]

Hi Everyone
I am getting ready to order some aluminium (that's Australian for aluminum!) for my cat track and wondering what thickness people use.
I am looking at 3/4 inch (which for me ends up being 19mm). It is available in 1.6mm and 3.2 mm wall thickness. The man at the shop said to go with the thicker stuff (but I think he was just covering himself). I have read on here people using 1/16 inch square aluminium 3/4 by 3/4. Is that what everyone is using and its doing a good job? Getting the thicker stuff will double the weight and increase the price too so don't really wish to get it unnecessarily.
I plan on making the pieces 16 inches wide for a total length of maybe 80 inches and to press around 50psi.
Thanks for the help as always.

I found this thread. It answers a lot about steel, but not aluminum thicknesshttp://www.skibuilders.com/phpBB2/viewt ... k+aluminum