The B335 carries 28 gallons in a molding that weighs 82 lb empty - a wall-to-capacity ratio that puts it firmly in Ronco's heavy-service tier. Blanks like this get specified when the tank will live somewhere hard: against a working hull, in a bilge that sees impact and vibration, on a boat that gets trailered and pounded. The extra polyethylene is not padding on a spec sheet; it is the difference between a tank you install once and a tank you replace.
It comes without fittings because a custom-fit tank deserves custom ports. Print the drawing below, use the fitting planner on this page to mark fill, vent, outlet, and any accessory port, and Ronco spin-welds or thread-installs each one to your marks. That build-to-order step happens in Tustin, California, where the company has rotomolded marine tanks since 1974. Ordered for fresh water, the shell is FDA-compliant and safe for potable supply; ordered for waste, the same dual-role B-series molding serves as a rugged gray or black holding tank.
Full, the tank holds about 234 lb of water on top of its own 82, so treat the bearers as structure, not trim. If your installation is gentler and weight matters more than armor, the lighter blanks near this capacity in the boat tank category are worth a look; RV builds should start at RV water tanks. The full line is on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B335 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.
