You're quite right. I'd like to add that hardware store metal pipes may not have good quality control - might want to check if they are suitable for compressed

You're quite right. I'd like to add that hardware store metal pipes may not have good quality control - might want to check if they are suitable for compressed air. Just being metal isn't enough. (For example, I would not use metal conduit and fittings designed for electrical wires.) For another example, don't use hardware store metal bolts and screws for things like holding your car's transmission in place. The quality of those bolts is erratic and they're poorly made. Tacoma Screw is my go-to place for quality fasteners. P.S. I have an air compressor, they work great for certain tasks like cleaning the dirt out of my car (!). But the pressure vessel is dangerous. Don't buy used compressors, only get new ones. If there are any dents in the air chamber, get a new one.