SDrvperThis, if you cant make good welds the rail is not going to last that long, especially if you are going hard on it.
Not really. Unless you do really really really awful welds and just kind of barely tack it together you're probably fine. I mean you and your friends hitting a rail in the backyard. If that rail is made of steel, and held even decently together it's going to be hard to fuck it up. And even then if you didn't build it right and you break it you can fix it.
OP What kind of material do you have access to? If you have to go out of your way to get it you might want to build a couple rails to make it worth while. Metal rails really aren't that expensive to build, especially for backyard length. You could build an unskirted 20 foot flat rail for just over $100
If you want some high quality tools that will last forever don't listen to this next part.
IF you're poor and want the tools you need to build a rail, find out where the closest harbor freight is to you. You can get a cheap welder there for $100 sometimes even less. You can also pick up a grinder for $15/20. Sure harbor freight tools are notorius for being sketchy but they can get the job done and are cheap as fuck.
If you want to spend a little more you can get a nice grinder for 50. The cheap ones you're getting a little more risky but if it lasts it's pretty easy to get your $15 worth. Especially if you're only building one rails.
I think all the shitty welders come with a ghetto mask that you can use to weld. Really all you would need for one of them is some wire. Grab a 5 pack of tips as well. They're cheap as fuck like $1. Also grab a couple extra grind wheels and a 3 pack of flap discs. The grind wheels are like $1 each there. The flap disc pack are around $10 for a 3 pack. If you don't have a saw and are only building a rail or two you can do it with cutoff wheels. The packs of those are cheap but you'll eat through them fast. A 10 pack is like $8 but they don't last that long. At the same time you don't have to make THAT many cuts. IF you're going to want to do more rails in the future might nto be bad to invest in a cheap chop saw. The cut off wheels are still nice for getting in to hard to reach places.
For a basic flat rail you really don't need much and they aren't hard to build. If you're rail is going to be 20' or less you can use one piece for the top and just cut out your legs so the top will automatically be smooth (As long as you clean the shit off it).
For kinks just cut one of your pieces at an angle and weld it. Make sure to grind the top and the top of the sides where you'll slide.
Don't leave huge gaps between the first leg and the end of the rail. A small gap is fine and useful for linking rails and moving them around but if it's too big you can end up with a diving board. Then when you jump onto the rail or switch up at the end you'll feel the bounce and it could throw you off.
If you want to build one go for it.
"When I win the lottery I'm gonna buy a mansion and name it "theabortionators estate" you can come an go as you please. Ill have a motorcycle in the garage you can run into a tree" -Kevtron