plumbing-help needed

[LittleFlower]

I would like to be able to pump the waste from the head directly overboard. So, in hopes of not
necessitating an
additional thru-hull, is is possible to add a t-connector to the cockpit drain so that the head and
the cockpit drain
will share the same thru-hull for overboard discharge? The other neighboring
thru-hull is
the bilge pump discharge.

Any suggestions?

[TheFrog]

It may be possible to T into the cockpit drain but you should think about what would happen if the cockpit drain clogs and can't keep up with the head pump. The flow will then reverse up into the cockpit!

[sailingdog]

My general recommendation isn't to plumb the head so that it can pump overboard, but to plumb the holding tank so that it can be pumped overboard. This is probably a better solution, especially if you're planning on cruising long-term at any point—since pump out facilities aren't always available or are expensive.

Don't connect any black water to a cockpit drain through hull. It will leave your cockpit smelling fairly badly and stain the side of your boat, since many cockpit drains are above the water line.

If the bilge pump, pumps overboard below the water line, that might be a good option, and you could use the bilge pump itself, if it is a big manual diagphram bilge pump to do the pumping.

If not, you really need to bite the bullet and install a new through hull for the waste line, regardless of whether it is direct from the head or from the holding tank.

Originally Posted by LittleFlower

I would like to be able to pump the waste from the head directly overboard. So, in hopes of not
necessitating an
additional thru-hull, is is possible to add a t-connector to the cockpit drain so that the head and
the cockpit drain
will share the same thru-hull for overboard discharge? The other neighboring
thru-hull is
the bilge pump discharge.

Any suggestions?

[lbdavis]

you could put a Y valve in place and only pump out when you aren't shipping water into the cockpit. i.e., leave the y-valve open to the "cockpit scupper to thru-hull" setting and swith it when you need to pump your tank.

You do risk the smell of holding tank seeping into the cockpit.

[jbondy]

We don't know much about your current setup. Do you currently have a holding tank? I agree that sharing a thruhull for pumping out waste sounds like a disaster waiting to happen. And you will have odor in the cockpit. When the toilet pumps out, the last of the waste will remain in the hose to the seacock. Unless you have an electric toilet, the amount of pumping you will have to do to fully evacuate waste from the hose will be excessive.

The plumbing is simple. I've plumbed the head to a holding tank. The tank has a single outlet that goes to a T. One side of the T is connected to the deck pump-out. The other side to a macerator pump to a seacock/thruhull. Whe the deck pumpout is used, the seacock is closed, so the suction empties the tank (rather than the ocean). When the macerator is pumping, the deck fitting is closed, so the pump is emptying the tank rather than sucking in air from the deck fitting.

I used to have two Y-valves so that the toilet could bypass the holding tank and go directly to the outlet thruhull. This added 6 connections and 2 valves to a system in which no leaks are tolerable. It worked well at first, but didn't last. KISS

[sailingdog]

Basically the same setup I have.

The plumbing is simple. I've plumbed the head to a holding tank. The tank has a single outlet that goes to a T. One side of the T is connected to the deck pump-out. The other side to a macerator pump to a seacock/thruhull. Whe the deck pumpout is used, the seacock is closed, so the suction empties the tank (rather than the ocean). When the macerator is pumping, the deck fitting is closed, so the pump is emptying the tank rather than sucking in air from the deck fitting.

[RAGTIMEDON]

Both Joel and SD have the setup I had on my 28 o"day. I put it in while the boat was in the water. Take your main halyard , add a line so you can get to another dock a couple slips over, tie it off. Then go back to your boat and winch the mast over, exposing part of your bottom. Drill the hole several inches below the water line, insert thru-hull, caulking thoroughly. When all is secure, let your mast upright. Mount the y-valve well above the water line with one hose to the new thru-hull, one to the deck plate, and one to the holding tank. Worked well for me! I now have another boat, and when I replaced my holding tank I sealed the thru-hull, because I am plan to retire on the Great Lakes, a no discharge zone. But if I were at sea, the outlet from the tank would be just as Joel describes!

[sailingdog]

This is not the recommended way to do it IMHO, but it would work, provided your marina doesn't mind having the lines go across several slips, the weather is relatively calm and you have a solid hull. If you have a cored hull, you're really going to want to haul the boat so you can properly pot the fastener holes and through-hull opening.

Originally Posted by RAGTIMEDON

Both Joel and SD have the setup I had on my 28 o"day. I put it in while the boat was in the water. Take your main halyard , add a line so you can get to another dock a couple slips over, tie it off. Then go back to your boat and winch the mast over, exposing part of your bottom. Drill the hole several inches below the water line, insert thru-hull, caulking thoroughly. When all is secure, let your mast upright. Mount the y-valve well above the water line with one hose to the new thru-hull, one to the deck plate, and one to the holding tank. Worked well for me! I now have another boat, and when I replaced my holding tank I sealed the thru-hull, because I am plan to retire on the Great Lakes, a no discharge zone. But if I were at sea, the outlet from the tank would be just as Joel describes!