i see alot of people asking the obvious questions so ima just make this and hope it helps someone
I would recomend using steel and either welding it or attaching it to a wood fram like you would with pvc
1. get a metal drill be as wide as the screw part of the screws you will be using
2. plan out where you are going to put the holes, one hole per 1 foot isnt neccesary just use one per 2 feet and at the ends
3. drill a hole all the way through, then widen the top hole so the head of the screw fits through
4. apply to wood with the screws!
its just the same with pvc
now you can make the frame howevr you want it according to height and length and stuff
and height too.
im just going to talk about top sheet, the popular one is hdpe, but a step up and more professional topsheet will be UMHW. This is what is used for grind parts in top end rollerblades. it is hard and will not catch at all. super high duty, unless you have concrete for bases this will last a long long long long long time.
to apply be sure you are supporting the topsheet with wood, and then drill holes so that the head of the screw is below or atleast flush with the topsheet drill all the way then around the top so its wide for the screw head
i dont know what countersinking scews is but iv heard people suggest that
could someone post a tutorial for boxes in this thread and one for dropins