I purchased a new Hawk shell with a furnace a couple of years ago after camping out of a fiberglass shell for 25 years...an amazing upgrade. I have discovered that I don't like to open the door on a winter morning to dispose of dish water, etc. I built this 'sink' out of a scrap of masonite, a funnel, some tubing, and a piece of angle iron. The angle iron enables me to hook one edge under the hinged shelf and secure it with a clamp. Using a nylon barb I can attach it to tubing that directs the waste water under my pickup. If I am someplace where this is not appropriate I place the short tube into a container inside. It installs or removes in seconds. All I bought was the funnel.