Six gallons, 20 x 11.5 x 7 inches, 11 lb empty: the B357 is the smallest dual-role molding on this page, and small is precisely its job. This is the tank for the boat or van system that bigger tanks cannot reach - a dedicated drinking water supply beside the galley, a gray water catch under a wet bar sink, a day tank for a center console. At 7 inches tall it tucks under seats and into console voids that were never meant to hold anything.
Ronco lists it as water or waste, and the fittings you order make the call. Fresh fittings: FDA-compliant potable molding. Waste fittings: the same shell becomes a compact holding tank for gray or black water. Pick the career before the first fill - a waste tank never returns to fresh service. Whichever role you choose, the ports are installed to your marks: print the drawing below, place them with the on-page fitting planner, and the fittings are spin-welded or thread-installed in Tustin, California, where Ronco has molded to order since 1974.
Full, it weighs about 50 lb - deceptively serious for its size, so strap it to structure. The next sizes up are in boat tanks and RV water tanks, the dedicated waste shapes in RV holding tanks, and the entire Ronco range on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B357 dimensional drawing - print it to plan your install and mark exactly where you want fittings located; Ronco installs spin-weld or threaded fittings to your marked spec.
