Installing fittings on a flexible water or fuel tank is simple, though it can be a little scary. The reason is simple: you have to cut a hole in your brand new tank.

Most fitting kits contain four parts: The fitting, a nut that will screw onto the fitting, and two sealing washers.

Once you have determined where your fitting will be located—and you should put some thought into this—center one of the sealing washers in that location and trace around the inside of the washer. This will determine the size of the hole you will need to cut.

Now carefully cut a starting hole for your scissors inside the outline you traced on the tank. Carefully cut the circle out with a sharp pair of scissors and be sure not to cut through the opposite side of the tank.

Place a sealing washer on the fitting and work the fitting and washer through the hole you just cut. The fabric should stretch easily to allow the flange of the fitting inside the tank. Place the second sealing washer over the fitting. This will give you a sealing washer inside and outside the tank.

Thread the nut onto the fitting and tighten to finish the installation. It really is as simple as it sounds. The hardest part is getting up enough courage to make that first cut.PAUL ESTERLEFill the tank to check for leaks and judge the size, then measure, cut the hole carefully and fit.