The Clamdoor fiberglass bulkhead looks like the hood of a car and is put together like a boat. It's formed in a mold with marine fiberglass, then coated with a tough, two-part epoxy gel coat matte finish. The Clamdoor costs about twice as much as a steel bulkhead (it lists for $497), but since it weighs only 75 pounds (as opposed to 200 pounds for steel) and comes fully assembled, the manufacturer says it can be installed in only 20 minutes. It's designed to be maintenance-free, never needs repainting, and is available in three standard colors: brown, gray, and green. (Thirty additional colors are available as a special order.) The manufacturer stresses the Clamdoor's ease of operation: A