Refits rarely go according to the original plan, which is why the Ronco Plastics B283 is deliberately uncommitted: a 65-gallon marine molding that becomes a fresh water tank or a gray or black waste holding tank depending on nothing more than the fittings you order. Boatyards like stocking one part number that can close out either side of a plumbing diagram. The molding weighs 102 lb dry; as a water tank, a full load runs about 542 lb, so give it a mounting platform commensurate with the job.
The decision point is the fitting order. Specify fresh water service and the FDA-grade polyethylene carries potable water; specify holding duty and the same heavy wall takes on waste. Either way Ronco installs each spin-weld or threaded fitting at the locations you mark - there are no pre-punched ports to work around. Print the drawing below, lay out your fill, discharge and vent runs on it, and let the on-page fitting planner catch any conflicts before the tank hits the mold shop queue.
Ronco Plastics has been building exactly this kind of tank in Tustin, California since 1974. If 65 gallons overshoots your locker, the boat tanks collection steps down in small increments, and the full Ronco Plastics catalog covers the RV side of the family as well. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B283 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.
