home depot by me usually only has 3” pipes. get a 3” 10 ft and drill it to a 10 ft treated 2x4. u can also grab 2 2” pipes and fit them both onto a 2x4 so u have a flat rail
EDIT: for what it’s worth, building a single rail should only cost roughly 40 bucks, so u don’t HAVE to plan on storing it over the warm months, u could just build a new one next winter
**This post was edited on Feb 10th 2021 at 11:08:33am