At 42 gallons the B237 crosses the line from day-boat convenience into genuine cruising capacity - enough fresh water to keep a family aboard for a long weekend without rationing the galley tap. The molding keeps that capacity civilized: 36 x 25 x 12 inches, a wide flat slab that sits low in a bilge or under an RV floor instead of towering over it.
It is a B-series dual-role blank, which means the 42 gallons is yours to assign. Fitted for supply, the food-grade polyethylene serves potable fresh water; fitted with waste inlets and a dump, the identical molding becomes a gray or black holding tank. Nothing is plumbed when it arrives - print the drawing below, mark where each fitting goes, and use the on-page fitting planner to choose spin-weld or threaded hardware. Ronco installs to your marks per order.
Respect the mass: the tank itself is a manageable 39 lb, but at 8.34 lb per gallon a full load runs about 350 lb, and that weight should ride on a flat, supported platform as low in the hull or chassis as you can put it. Molded in Tustin, California by a shop that has done nothing but this since 1974. Related shapes live in our boat tank category and RV holding tanks; the full range is on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B237 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.
