Hi,
Let me say that I have been reading Peggie Hall's posts on this forum and I can't believe how helpful she has been to all of these readers who would be otherwise left scratching their collective, well, heads. Thanks in advance.
I'm laying out plans for a new holding tank system in my new-to-me Pearson 365. The old sanitation system was a disgusting, putrefying, dysfunctional nightmare, that the previous owner, unfortunately, continued trying to use, until it virtually exploded. I have just completed the truly disagreeable task of removing all of it. Now, it's a nice, odorless blank canvas, waiting for an artful solution.
I'm quite attracted to the idea of an above-the-waterline holding tank that would allow me to employ gravity for routine emptying. For many years, I have guided whitewater river expeditions. On these trips, we have to carry out any solid human waste in modified rocket boxes, which have very limited capacity. To preserve precious "groover" space, we have a policy of "pee in the river, poop in the box," which is actually sanctioned by most river permitting agencies, including the National Park Service. I see no reason not to have a modified version of the policy for my guests on boating outings, which is: "pee in the head (ocean), poop in the toilet on shore." A gravity-emptying system would allow pee to simply run through the system and out to sea 99 percent of the time. Multi-day trips, or emergency deposits of solids, would require shutting the thru-hull valve, but the gravity system seems like an ideal, low-maintenance solution to me, for most of my boating, most of the year, as long as I'm able-bodied enough to walk the few dozen yards of dock to the marina toilet.
After ripping out yards of leaking, solids-packed hoses, a broken, dysfunctional "whale" pump, and numerous clogged valves and cracked fittings, all seemingly predestined to fail, I'm determined to have much cleaner, simpler system on my boat.
Objectives:
1) Simple, clean, odor-free system with a minimum of hoses and moving parts.
2) Gravity (Newtonian) clean out, if possible, supplemented by pumping when necessary.
3) Capacity - about 20-25 gallons, to accommodate a family of four for a 3 or 4-day weekend
4) Normal state - completely empty about 95 percent of the time, reducing concerns about location of extra weight.
5) Location - In the head compartment, if possible, while meeting the previous requirements
I have identified three spots in the head compartment that could achieve my objectives: vertically, against the wall behind the toilet; horizontally, against the wall behind the toilet; or a wedge-shaped tank in the hanging locker between the sink and the hull. There are actually two full-size through hull fittings dedicated to head use on the boat -- one from the one-before-the-previous owner, that's under the starboard settee and destined for removal, and another that's directly under the and behind bathroom sink. The latter one is directly below the back-of-sink locker, so would be well suited to serving as a gravity outlet, although I'm willing to remove them both and start over on the next haul-out.
I set out looking to find a polyethylene tank from Ronco, Raritan, etc., and have literally considered each of the 500 or so tanks from the two companies, as well as the other more anonymous companies I can find. Nobody makes a single tank that fits perfectly -- or even close -- in any of the spaces I've mentioned, although some would fit if I settle for a very small capcity (11 gallons or less) or very awkward placement, eg., jutting out uncomfortably behind the toilet. I considered a flat-pack-shaped tank behind the toilet as my favorite option, but there are very few that are thin enough -- 6 inches requires pushing the toilet forward off it's current ledge -- and none provide enough volume. I have built mockups from cardboard of several tanks that could work, but they're just awkward and take up too much space in the small compartment.
The locker behind the sink is looking like the best option. It's a wedge shape, about 10 inches deep on the fore end, 13 deep aft, and 20 inches high and 32 inches wide. It's much deeper near the top, however, one of the hull tabs and chain plates cuts into this wedge, so that without creating a tank with a slot cut out of the back, the biggest that would fit is a wedge 6 fore x 9 aft x 19 high x 32 wide. Nobody makes a tank this shape, so my only option would be a 10-gallon flat tank (6 inches deep) or to fabricate one (I'm very experience with fiberglass, epoxy and polyester); or to have one plastic welded (my first quote was for $1,050 -- which is way out of my price range.) I'm tempted to go with the 10-gallon solution, since I expect it to be mostly empty, anyway, but I'm trying to be forward thinking and consider the requirements of family and future guests.
I'm attaching drawings of what I propose, as well as a quick model of the tank itself. I welcome feedback and criticism. I would much rather work this out on paper than by installing a quick-easy solution that will need re-fixing later.
Thank you again!
Let me say that I have been reading Peggie Hall's posts on this forum and I can't believe how helpful she has been to all of these readers who would be otherwise left scratching their collective, well, heads. Thanks in advance.
I'm laying out plans for a new holding tank system in my new-to-me Pearson 365. The old sanitation system was a disgusting, putrefying, dysfunctional nightmare, that the previous owner, unfortunately, continued trying to use, until it virtually exploded. I have just completed the truly disagreeable task of removing all of it. Now, it's a nice, odorless blank canvas, waiting for an artful solution.
I'm quite attracted to the idea of an above-the-waterline holding tank that would allow me to employ gravity for routine emptying. For many years, I have guided whitewater river expeditions. On these trips, we have to carry out any solid human waste in modified rocket boxes, which have very limited capacity. To preserve precious "groover" space, we have a policy of "pee in the river, poop in the box," which is actually sanctioned by most river permitting agencies, including the National Park Service. I see no reason not to have a modified version of the policy for my guests on boating outings, which is: "pee in the head (ocean), poop in the toilet on shore." A gravity-emptying system would allow pee to simply run through the system and out to sea 99 percent of the time. Multi-day trips, or emergency deposits of solids, would require shutting the thru-hull valve, but the gravity system seems like an ideal, low-maintenance solution to me, for most of my boating, most of the year, as long as I'm able-bodied enough to walk the few dozen yards of dock to the marina toilet.
After ripping out yards of leaking, solids-packed hoses, a broken, dysfunctional "whale" pump, and numerous clogged valves and cracked fittings, all seemingly predestined to fail, I'm determined to have much cleaner, simpler system on my boat.
Objectives:
1) Simple, clean, odor-free system with a minimum of hoses and moving parts.
2) Gravity (Newtonian) clean out, if possible, supplemented by pumping when necessary.
3) Capacity - about 20-25 gallons, to accommodate a family of four for a 3 or 4-day weekend
4) Normal state - completely empty about 95 percent of the time, reducing concerns about location of extra weight.
5) Location - In the head compartment, if possible, while meeting the previous requirements
I have identified three spots in the head compartment that could achieve my objectives: vertically, against the wall behind the toilet; horizontally, against the wall behind the toilet; or a wedge-shaped tank in the hanging locker between the sink and the hull. There are actually two full-size through hull fittings dedicated to head use on the boat -- one from the one-before-the-previous owner, that's under the starboard settee and destined for removal, and another that's directly under the and behind bathroom sink. The latter one is directly below the back-of-sink locker, so would be well suited to serving as a gravity outlet, although I'm willing to remove them both and start over on the next haul-out.
I set out looking to find a polyethylene tank from Ronco, Raritan, etc., and have literally considered each of the 500 or so tanks from the two companies, as well as the other more anonymous companies I can find. Nobody makes a single tank that fits perfectly -- or even close -- in any of the spaces I've mentioned, although some would fit if I settle for a very small capcity (11 gallons or less) or very awkward placement, eg., jutting out uncomfortably behind the toilet. I considered a flat-pack-shaped tank behind the toilet as my favorite option, but there are very few that are thin enough -- 6 inches requires pushing the toilet forward off it's current ledge -- and none provide enough volume. I have built mockups from cardboard of several tanks that could work, but they're just awkward and take up too much space in the small compartment.
The locker behind the sink is looking like the best option. It's a wedge shape, about 10 inches deep on the fore end, 13 deep aft, and 20 inches high and 32 inches wide. It's much deeper near the top, however, one of the hull tabs and chain plates cuts into this wedge, so that without creating a tank with a slot cut out of the back, the biggest that would fit is a wedge 6 fore x 9 aft x 19 high x 32 wide. Nobody makes a tank this shape, so my only option would be a 10-gallon flat tank (6 inches deep) or to fabricate one (I'm very experience with fiberglass, epoxy and polyester); or to have one plastic welded (my first quote was for $1,050 -- which is way out of my price range.) I'm tempted to go with the 10-gallon solution, since I expect it to be mostly empty, anyway, but I'm trying to be forward thinking and consider the requirements of family and future guests.
I'm attaching drawings of what I propose, as well as a quick model of the tank itself. I welcome feedback and criticism. I would much rather work this out on paper than by installing a quick-easy solution that will need re-fixing later.
Thank you again!
