Fifty-five gallons in a 105 lb heavy-wall blank: the B351 is tankage as commitment. This is the molding for the boat that is being set up properly - a liveaboard's primary fresh supply, a sportfisher's washdown-and-galley reserve, a charter vessel that cannot afford a water failure mid-trip. Nearly two pounds of polyethylene per gallon means wall section that treats decades of slosh cycling, vibration, and the occasional dropped winch handle as background noise.
It ships as a bare molding because at this size the port map is everything: a badly placed pickup strands gallons you paid to carry. Print the drawing below, plot fill, vent, pickup, and sender with the fitting planner on this page, and Ronco spin-welds or thread-installs each fitting to your marks at the Tustin, California plant - the same made-to-order process running there since 1974. In fresh service the shell is FDA-compliant and potable-safe; ordered with waste fittings, the identical dual-role blank becomes a high-capacity gray or black holding tank.
Two weights govern the project: 105 lb arriving on your doorstep, and about 459 lb sitting in the boat once full. Price the first with the freight cost estimator, engineer for the second, and compare alternatives across boat tanks or the full line on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B351 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.
