My next door neighbor wants me to weld him up a lumber rack for his barn. Largest wood he will stack on there will be a few 1x12's but mostly 2x4's, 1x4's, maybe some rebar, or a pipe here and there.

The design is an A-Frame like a swingset with 1 foot wide shelves. He wants to go as economical as possible. The A frame will be 6 foot tall with 4 shelves. I will be welding it up with my Lincoln 125/225 ac/dc stick welder.

What would be best? I was thinking 1/'8" square tube. But what size? 1"? 1.5"? Or go to a thinner 14 ga 2" sq tube?
I don't have a pipe jig to fishmouth pipe was why I was thinking sq tube.

Looking for medium strength.

Any suggestions on what to make it out of?