I'm looking at the prospect of replacing the waste holding tank in my boat. I've read several recommendations that say to increase the size of the vent hose to 1" or 1.5" and ensure that the thru hull fitting doesn't have a screen that can become blocked. The problem is where to find an open hull fitting for that size hose. Any suggestion on where to find such a fitting?
You're not looking for a "vent" thru-hull...those are all the same size--5/8"--and all designed for use on fuel tank vents,...boat builders use 'em on everything 'cuz it costs 'em a lot less than using the right one for each application. So you're looking for a plain ol' "bulkhead" or "mushroom" thru-hull (see photo). I googled just "thru-hull fitting" and came up with all kinds of sources for open "bulkhead" fittings in all sizes up to 2". 1" is about the biggest hole you want in the side of a 35' boat. Stainless, Marelon or bronze is ok...nylon is not, UV will turn a nylon thru-hull into powder.
Ronco Plastics
Ronco Plastics Marine Catalog is your best source for the tank...they make top quality, thick-walled rotomolded PE tanks for a very reasonable price and have more than 400 shapes and sizes, over 100 of which are non-rectangular...and they install fittings in the quantity, sizes and locations specified by the customer when they make the tank.
If you'd like some help spec'ing it all out, give me a shout. Meanwhile you might want to check out "The NEW Get Rid of Boat Odors" shown at the bottom of this page...it includes step by step instructions for replacing a tank and whole bunch of other good info.
