I've made many of them. Go to Home Depot and buy a 10' section of pvc pipe of desired diameter. Buy some pvc glue, a plastic plug (these are small indented opaque disks that fit snugly into the end of the tube), a cap (that fits snugly over one end), and some parchute cord. Saw the tube to size. File or sand smooth the rough sawn end and glue in the plug. Next drill a hole in the cap about the size of the parachute cord. Drill another hole a few inches below the top of the tube. Work the cord into the hole at the top of the tube and then tie an overhand knot in the end in the tube. Burn smooth by melting the knot end. Put the other end of cord through the cap hole, tie a knot, and melt the knot end. You now have apractically indestructible tube with cap attached for your rod or rods.