How to butt weld 2 pipes together straight?

Thanks for all your helpful replies. I should have thought of using angle iron.

I'm using oxy-acetylene welding. I've always felt it gives me better control over the weld puddle than a MIG welder does.

We had a Tractor Supply store open up in a town near here recently. I went there, but they denied having any steel pipe. I haven't checked their online catalog, though.

I picked up a lot of 2-1/8" thinwall galvanized pipe that had been the framework of some portable stalls at a horse ranch near here that went broke and closed down. (In this area, keeping horses used to be really popular, but it seem to be a luxury that many can no longer afford.)