ahh dont use pvc, it sucks, it sticks, its soft enough for your edges to cut in to it etc. if you acutaly want to build rails, take a welding class or have someone you know who can weld to teach you, it really easy and you can learn how to do it well fast. and if you serious about maken rails buy an Arch welder, you dont need anything more then 100ampers and you can buy a ok one for about 200-400 at a hardware store. its a lotta money but you will find that welding is a really handy skill/tool and you can build some Sick rails.