I had a small project along the side of the house, and needed a short piece of small diameter rod to pierce a caulking tube. The closest thing at hand, was a handle from a 5 gal. plastic pail. As I cut the plastic hand grip off, I realized a use for it almost instantly; Terracotta pipe! I cut the center ridge out on the chop saw, painted it with Rustoleum red oxide primer, and done. They do need a little trim on the inside of the cut end, but this project took longer for the paint to dry. The inside diameter is abut 5/16" at the small end, and 1 3/8" at the bell. Not knowing what the scale length of a pipe this diameter would be, I left the pieces at 3/8", which is 6' 6".
Don