Just wanted to mention that if you do want to use "1 1/2 inch" water pipe as a mast, you can make a perfect shim for it from a piece of standard 2" (0.050 inch wall) irrigation tubing. This tubing is 2" OD and 1.9" ID. If necessary, sand the pipe a little to get the tubing to slip over it. Now it will fit standard 2 inch mast hardware. Rick N6RK