Measure the depth of the flower pot in inches, from the bottom to the top rim. Subtract 2 inches from the total number and write it down. For instance, if the flower pot is 20 inches deep, you would write down 18 inches.
Use the measuring tape to measure the same number of inches on the plumbing pipe: You can start at either end. Use a hacksaw or pipe cutter to cut the plumbing pipe to the desired length.
Set the plumbing flange on the bottom of the flower pot. If the flange is wood, it may have screw holes that you can use to secure it to the base of the planter. Insert the plumbing pipe into the flange. This holds the plumbing pipe in place, so that it does not wobble around.
Fill the flower pot with gravel. This also helps to ensure that the umbrella does not move, as well as makes the flower pot umbrella stand look decorative.
Lay the waterproof fabric out flat on a working surface. Measure the circumference that you want the giant umbrella to be. Tie a piece of string to a fabric pen or chalk and the other end to a pin that you stick into the center of the fabric. This creates a type of compass. Trace the circle onto the fabric by moving the fabric pen or chalk around, while the pin is held in place. Use fabric glue to turn the edges under to hem a smooth seam at the end.
Dip the thin metal sticks into flux and solder them to the plumbing pipe. Turn on the soldering iron and hold the metal sticks up to the point on the pipe that you want to attach them. Apply the heat, which should be between 400 and 600 degrees Fahrenheit, until the pieces melt together. The metal sticks act as the umbrella spokes, and should be placed evenly around the plumbing pipe. Five metal sticks should be sufficient.
Use a hot glue gun to attach the underside of the fabric to the metal spokes. Thread a needle with a matching colored thread and stitch the fabric around the metal spokes at a few randomly selected spots. This ensures the fabric stays in place as you create a canopy with the waterproof fabric.