Like many of us on the list, the original 30 gallon holding take in the bow was never used as such, and was put to work as another fresh water tank. The holding tank is a bladder under the V berth and yes, it is a poor excuse for a proper repository. I would like to replace it with a hard walled tank.
One of my issues is figuring out how to run 2 vent lines from under the V berth to some where below the toe rail, with out screwing up the nice wood paneling. But my biggest problem is getting a tank into the space The covering over the V berth space would be virtually impossible to remove (and if anyone could tell me how I would be in their debt). Therefore, I think need to have a tank fabricated that I can squeeze through the access hatch. Once I get it through, I can glass tabs to the hull to hold the tank in place. My question for you is if you know of a good operation on the east coast that can create such a tank. I am located in NYC, and the best would be somebody local in case I need to turn over templates or mock ups, or if they need to see the boat.
I will say this. I love doing most all work on Indigo (except, perhaps, working on the quadrant ). This is one job, though, that I would love to pass off to the yard if I thought for a second that they would do a decent job at it.
Thanks for any help you can provide.
Michael - >"Indigo" C+C 35 Mark III

Not sure if I understand your concerns correctly. We have a 35, and the hatch cover under the cushions ofthe V-berth is big enough to remove a 20 gal tank for repairs. It also fits through the bulkheads and out the companionway. Maybe ours was an add on, but the waste clean out, and the vent, run on the port side to the bulkhead, and at the only place where they could be visible from the v-berth, they run under an angle panelling. The wood is angled in the corner under the shelf locker, and just above the cushions. Is this standard or an add on from a previous owner????
Your second vent could be plumbed up the starboard side behind the chest of drawers. A little drilling under the toe rail, and you have a second vent.
Klaus

On our 32 we added an anti-siphon loop after a scary near-flood. Not only did we eliminate siphoning, but the intake side is now "self-draining," since the top of the loop is up near the level of the gunwale. We sail in fresh water, so I don't know for sure if this would be the answer to keeping dead saltwater beasties from stinking things up, but it seems like it might (plus I don't think I'll ever own a boat again without one).

The near-flood happened during the twice-yearly Chicago river migration two seasons ago. We were taking our 32 from the yard to the lake in a flotilla of a couple of dozen boats. The trip is only a few miles but takes between 3 and 5 hours because we have to go through downtown and pass under something like 20 drawbridges. My then-6-year-old used the head and failed to pump it properly, leaving the intake side open. We were busy on deck and didn't notice for quite a while, by which time the water was over the floorboards. Brief panic, a scramble for the pump handle (everything wasn't really stowed properly yet), and all was well. (Kind of a nervous start to the season, though.)
As for the loop. If your 32 is like ours, there's a cabinet with a sliding door behind the head tucked right up under the gunwale. We drilled two holes in the underside of that and hid the anti-siphon doohickey inside, out of view. The intake hose comes in at the floorboards, runs up the side of the hull, into the compartment to the doohickey, them back down to the head. It's cramped, but it fits pretty nicely and looks fine.

Walt,
I ALWAYS turn off my head intake when leaving the boat. It is the easiest way to prevent a flood. But can you describe in detail what caused the near-flood? And for us 32 owners, can you please tell us where did you find space in the compartment where the head intake valve is to get up to the gunwale with the loop? (if that is where you put the ant-siphon loop in). Otherwise where did it go?
Thanks in advance - Tom Anderson - C&C 32 Nonpareil

Btw...IMHO, the best source for water and holding tanks in the country is Ronco Plastics in CA. They were our main vendor for more than 10 years (till I sold my company). They offer more than 400 different shapes and sizes, including more than 100 that are non-rectangular...their tanks are extra-thick walled--starting at approx 3/8", which is at least 50% thicker than anything in the discount marine catalogs except SeaLand (who only offers a VERY limited number of shapes and sizes)...their tanks are made to order, which allows you to spec the fitting locations and sizes YOU want...and their prices are excellent.
Ronco's website, which includes their entire catalog, is at http://www.ronco-plastics.com or you can call 'em at 714-259-1385 for hard copy of their catalog.
This isn't a a solicitation, only recommending a company I always found it a pleasure to do business with, the same as any of you would.

FWIW the problem with the seacock on the 32 is that it is, indeed, under a settee. As I said in a different post, our original problem occurred when my six-year-old needed to use the head while we were very busy on deck. For him to get to and work the seacock just wasn't going to happen. Adults can open and close the seacock (with difficulty) but it's a pain for us, too. We always close it when we leave the boat, but it's nice being able to have it open when we're hanging out at the dock, etc.

An alternative to moving the seacock: install an inline ball valve next to the toilet in the head intake line. If you can't close intake at the hull, close it where you can. 'Cuz as I mentioned, a vented loop won't prevent water being forced up the intake line when you're screaming along 7k from overflowing the toilet.
Peggie

Peggie & Klaus -
1) Thanks for the Ronco lead. I will definitely use it.
2) In terms of the hatch cover issue. I have a total of 4 hatch covers under my cushions. 2 are on the port and starbord sides of the V, and are approximately 1 foot by 1.5 feet (from memory). It would be difficult to get a tank of any size down those holes and in the space that is under them. Furthermore, the port hole gives access to the head Y valves and manual pump, and the space is filled by the plumbing for those items. The third hatch is on the center line, just above the notch in the V. This hole is approximately 2 foot by 2 foot, and opens into the largest storage space. The through holes for depth, speedo, head intake and head output are all on the port side, with the plumbing and cables leaving little hull surface available to mount any kind of tank. The starboard side is free of obstacles, and currently holds the bladder that is used as a head holding tank. The fourth and final hatch is at the forward, end of the berth, and is shaped like a trapezoid. It is maybe 2 feet by 3 feet and gives access to the primary, hardwalled tank in the berth. The tank fills up the entire space under this hatch and was original to the boat. This is the one I believe was intended to be used either as a head tank or fresh water tank. In my case it is fresh water. The only logical place for a hard walled head tank is where the bladder is currently. The only way to get a tank in there, without cutting the fiberglass that serves as a berth surface, is to go through the 2X2 hatch that is on the center line just forward of the notch in the V. The tank itself will have to be curved/angled to fit against the curve of the hole, and approximatley 2 X 2 X 2 feet deep at the deepest. The depth would taper from 2 feet at center line to something like 1 inch at the outboard edge. In terms of venting, you are on the money in terms of running one line up through the starboard lockers and hiding it that way. My problem is finding a way to run one forward that will not have to be exposed to the V berth. I have no angle of wood to hide it behind. Guess it will require a nice winter afternoon on the boat muddling through the design.
If anyone has done this job and can give me some advice, I would appreciate it.
Thanks. - Michael - "Indigo" C+C 35 Mark III

Michael,
I have installed a 24 gal rectangular tank under the 2' x 2' centerline hatch in the "V" berth on a 35 Mk II. It's a tight fit but it works great. It sits on a platform that it bolted between the bulkheads (one that separates the compartment from the living space, and the other that separates it from the forward compartment under the smaller centerline hatch). If I can help, fire away.
Gary - S/V Expresso - '75 C&C 35 Mk II

Michael
You have a lot of options...it just depends on the shape of tank.
IF it has a 1/5" discharge fitting (or an inspection port that will allow you to install one--I'll explain how if necessary), I'd convert that tank to holding and find a place for another water tank--which COULD be a bladder. Although, except in rare instances, bladders are a disaster for sewage holding, there's no reason not to use 'em for water.
I think you'll find one that would work in the Ronco catalog.

"In terms of venting, you are on the money interms of running one line up through the starboard lockers and hiding it that way. My problem is finding a way to run one forward that will not have to be exposed to the V berth."
Another reason to use your existing water tank. Come off the top of the bow end of the tank, through the chain locker and out the hull about a foot below the toe rail.
Once you've had a chance to look at what's available (shapes, sizes) and whether or not it makes sense to convert your existing tank to holding, you're welcome to get with me one-on-one and I'll help you work out the logistics.
Peggie

Walt,
Could you please clarify if my understanding is correct:
1) through hull and sea cock
2) hose up to vented loop fitting in cabinet
3) hose down to head primary water intake.

My question is, would not the anti-siphon device stop the head pump to draw water? If the list above is wrong, please correct it.
Leslie - Phoenix C&C32 (1983)

It sounds a lot like the tank arrangement on our 29-2. I just plumbed in the bow tank, formerly fresh-water, to be a waste tank. Put in a lot of complicated plumbing involving two diverter valves and a manual pump (the West Marine "Chernobyl" arrangement), which eats up a lot of space, and was hell to do, but just plumbing it in as a holding tank would be easy. As it is, it still leaves lots of room for bottled water. We keep a gallon of quality water for drinking in the cooler all the time, and replace as we go along. The tank water we use primarily for cooking and washing; you get better tasting water and it cuts down on your permanent tankage needs. I suspect your deck fitting is black, for waste, not blue for water. I think the tank was usually used for a holding tank. Klaus knows of what he speaks.
Jim Watts - Paradigm - C&C 29 Mk II

Leslie Paal wrote:
Could you please clarify if my understanding is correct:
1) through hull and sea cock
2) hose up to vented loop fitting in cabinet
3) hose down to head primary water intake.

No. The vented loop has to go between the pump and the bowl...because your question hits the nail on the head:
My question is, would not the anti-siphon device stop the head pump to draw water?
Yep.
Peggie

Michael
I put a Ronco tank under my starboard settee on my 1981 34 last winter. The main part of the settee runs for and aft and had two hatches to get into it. I took my saber saw and cut the fiberglass so these two openings became one large one. After I installed the tank I took 2 inch wide strips if 1/2 in plywood and placed them under the fiberglass where I made the cuts and put counter sunk screws through the glass into the strips of plywood. This gave me a strong smooth surface for the settee cushions.
I took careful measurements of the area for the tank and went to the Ronco catalog. When I found a tank that looked the size and shape I could use I built a mockup of cardboard to see if it would fit. Marine Sanitation is Seattle put the fitting where I needed them.
I hope you understand what I am trying to say.
Phil Rousseau - "Altrice" - 1981 34

"The fourth and final hatch is at the forward, end of the berth, and is shaped like a trapezoid."
That's our too. What we have now, is a poly (??) tank that fits that shape that you describe, and sits inside of a well (??) Now being a long time C&C owner, I wonder if that's the remants of the C&C water tank. I always thought that it held the previuos tank, but it just may be the remants of it.
What I'll do is to take my video cam to the boat next thursday. We bringing back the last of the sole that's been refinished, and sailing in the Islands for a day or two. I'll do a vidcapture, and send it off to you as a jpg.
I'll do the tank, the vent and clean-out, and I'll shoot some of the plumbing.
Best I can do. - Klaus

Leslie,
I believe Walt said an anti-siphon loop, not a vented loop. I can assure you that a vented loop between the seacock and the pump will prevent the pump from drawing. How do I know? I tried it :-( After pumping the handle a few dozen times and hearing the vent gulping air, I felt pretty stupid.
Gary - S/V Expresso - '75 C&C 35 Mk II

Glenn -
The areas that cover port and starboard tanks in the main cabin do unscrew, and in fact are a ply, surfaced with some sort of laminate that sponges clean.
The surface that covers the V berth storage area is glass, and is one piece molded, all the way down the side of the V berth to the sole. Between that and the teak strakes that are used to line the cabin walls I can not figure out how to remove the surface without causing damage, hence the though of stuffing a new holding tank through the existing access hole(s). Peggy's solution of using the existing forward tank and then putting in a flexible freshwater bladder is even more attractive and probably less expensive.
Thanks - Michael - "Indigo" C+C 35 Mark III

West Marine catalog shows some 'doohickeys' called vented loops and are described as - "Prevents water from siphoning back into the marine head. The simple valve system allows air to enter the line when not in use, yet seals effectively as water passes through".
So what are they for?

Vented loops come in two sizes: 3/4" to go in the intake line (after the pump, ahead of the bowl), and 1.5" to go in the head discharge line. A vented loop in the head intake line prevents a siphon from flooding the head--and then the boat--with sea water through the head intake thru-hull
A vented loop in the head discharge line can serve a couple of functions: prevent an overflowing holding tank from creating a siphon and emptying itself in your boat through the toilet...prevent sea water from starting a siphon and flooding the boat through the toilet...prevent seawater from flooding a holding tank--and then the boat--by backing up through the overboard discharge pump, into the tank, and back to the head.
There should be a vented loop in ALL hoses connected to underwater thru-hulls. And they should be at least a foot above the waterline at any angle of heel.

Technically, siphoning is the process of a low pressure area behind a fluid moving downhill, pulling additional fluid uphill behind it, similar to a train pulling a long string of cars behind it over the top of a hill. When more than half of the train gets over the top no energy is required to get the rest of the cars to follow. The key phrase here is "low pressure". Actually the pressure differential between the low pressure in the hose and the outside pressure causes the fluid to move. An anti-siphon valve is actually a check valve that allows air to enter at the top of the loop, when the pressure is low, but doesn't allow the fluid to escape when the pressure is high. The valve looks like a miniature joker valve. Unfortunately, the pump in the marine head tries to draw water in with a low pressure as well, and if you let air into the line (with an anti-siphon valve), you neutralize the pressure difference and there is no pressure to move the fluid.
I guess I should keep my day job and not become a technical writer, but I hope this is understandable.
Gary - S/V Expresso

I'll bite; what is the difference between anti-syphon and vented loop. Till now i tought of them as same. I am interested in learning something new.
Leslie.

Leslie,
Technically there is no difference as Peggie has reminded us. However, some people call a vertical loop of hose an anti-siphon loop which it is not. A loop of hose will not stop a siphon, but is effective, for example, in a bilge discharge line the exits above the waterline at the transom. It will provide a barrier to water pushed by wave action entering the bilge line and travel down to the bilge.
Gary - S/V Expresso - '75 C&C 35 Mk II

Actually, it won't. I finally had to install a one way valve in my forward bilge pump discharge line to keep "ram water" from being forced over the loop and into the bilge. That may be due to the fact that mine is a 32' stinkpot and cruises at 20+ knots...a sailboat at 7k may not be able to generate quite that much force.