Trawler tankage: the B440 is a 44 gallon molding with a heavy 111 lb shell, the kind of tank you install once, glass a shelf under, and forget for a decade. Displacement cruisers and liveaboards load their tanks daily and empty them weekly, and that duty cycle rewards wall thickness over grams saved.
The B-series rule applies: this is a dual-role shell, fresh water or gray/black waste holding depending entirely on the fittings you order. Nothing is molded in. Print the drawing below, mark fill, draw, and vent - or inlet and pump-out, if this one is going on the waste side - and Ronco spin-welds or thread-installs each fitting to your marks. The on-page fitting planner sorts sizes and styles.
Plan structure around roughly 367 lb of water at full, delivered onto whatever you build beneath it. Molded in Tustin, California by Ronco, rotomolding tanks since 1974. The boat tank category holds the adjacent capacities, and delivery on a shell this heavy is worth a run through the freight cost estimator. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B440 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.
