Replying to rails for beginners

My brother really wants to start sliding rails and wants to build some in our backyard... I was thinking of just using PVC for him to learn on. How long would be a decent lenght to learn on.. I was thinkin on making them around 6-7' long and gettin some different widths to mix it up with...

Any other opinions are welcome...

Anyone living in the Toronto area wanna lend a hand in building some my brother wants to create a whole bunch all over our back hill or have a session once they are done and we have actual snow LMK~!~
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My halo needs some duct tape.

I'm tired of being an Angel I wanna be a Princess!