I have a pair of 1.5" x 1.5" (1/8" thick) aluminum square tubes that I want to use to make a narrow rack platform for my truck. Trying to get something done in the next few weeks before a road trip in mid July. The platform will be about 20" wide and 60" long. It will carry my two small water tanks, extra 3gal fuel can and small action packer or rubber maid tub with camp supplies. Not a big load and not really being used for anything more than road trips and general camping.
My idea is to use the two aluminum tubes as the sides and attach a base made of either plywood or aluminum tread plate. I'm not satisfied with the quality of ply I can get locally (poor quality exterior ply, or high quality cabinet ply but with no exterior glue) and tread plate is more money than I would have thought for such a small application. Curious if there are any other options I'm not thinking of. My goal is to be able to attach the base myself with bolts, no welding. And trying to keep material cost under $75.
Any ideas on other materials or methods of creating the base? I've though about aluminum cross trips but I think that would only really work well if I could have it welded which is definitely out of budget.