Head system rebuild

HeadScratcher

Lieutenant
Joined
Mar 27, 2021
Posts
27
Likes
13
First Name
Tim
I have a Nauset Coastal 27'. Made quite a few multiday trips on her this past summer. I've rebuilt the head (which is working fine). But we're getting some bad odors from around the holding tank. My plan is to replace the holding tank and all the hoses. They are 30+ years old. Two questions:
1) There is a fitting between the vent hose and the outside vent. What is this and is it necessary (see attached photo)? It reduces down from 1/2" to what looks like 1/4" tubing. At one point I thought the vent might be plugged, and we were getting some back gassing. But at this point, I figure its time to redo the whole thing
2) Can someone recommend a good quality sanitation hose to use as a replacement. What we have now is 1 1/2" white. I want to buy something that will contain odor, hold up over time, and not cost a fortune.
Also, any tips you can offer for doing this job would be appreciated. It seems pretty straightforward, except for running the hose through some tight spaces

Sandpiper vent fitting.jpg
 

TCL

Captain
Joined
Jan 29, 2014
Posts
891
Likes
663
Location
Annapolis MD, formerly Huntington NY
Boat Make
Sabre 36 The Captain's Lady
Definitely wait for Jerry to chime in, in the meantime…
I don’t like the small vent line. You need the tank to have good air flow so that it does not implode when you are sucking it dry. It’s also good to have a “Fart Filter “ on the vent line, but they also can cause a restriction.
 

Diesel Jerry

Admiral
Lite User
Joined
Oct 25, 2015
Posts
9,670
Likes
8,614
Age
43
Location
South Freeport, ME

CaptainHinckley

Captain
Joined
Apr 24, 2016
Posts
643
Likes
461
Location
Portland, Maine 43.6691 N 70.2409 W
Boat Make
1998 29' Sea Ray 1980 Bruno Stillman 35
1638122875440.jpeg If I may, we just went through this a couple years ago. Complete install of head and system. buy this book, it’s a quick read and inexpensive.anything smaller than 3/4” is to small imho. Also any obstructions in the path from tank to fresh air ithat inhibits free exchange is bad including carbon filters. Our boat has been odor free with two 3/4” vents, one each side of the vessel no filters just enzymes after pumping out. We’ve had to leave tankage for two weeks once with no odor. Follow the book. I can’t say that about some of my friends production boats when we have been rafting up Best ch
 

HeadScratcher

Lieutenant
Joined
Mar 27, 2021
Posts
27
Likes
13
First Name
Tim
If building a custom tank take this drawing into consideration. Again I apologize for the slapdash nature but my graph paper is at work. If it were me I would do 2) 3/4” vents going to opposite sides of the boat for good cross flow. Best thing to do would have those vents far apart on the tank. I would do a plate at the top of the tank and have all fittings and even the macerator mounted to it. Use a pick up tube rather than a fitting at the bottom of the tank.
View attachment 121913 Side view.
View attachment 121914
top view
Thanks for the insight. I believe I'm just going to go with an "off the shelf" tank. Todd makes a 9 gallon unit that matches exactly what's in there now.
 

HeadScratcher

Lieutenant
Joined
Mar 27, 2021
Posts
27
Likes
13
First Name
Tim
View attachment 121915 If I may, we just went through this a couple years ago. Complete install of head and system. buy this book, it’s a quick read and inexpensive.anything smaller than 3/4” is to small imho. Also any obstructions in the path from tank to fresh air ithat inhibits free exchange is bad including carbon filters. Our boat has been odor free with two 3/4” vents, one each side of the vessel no filters just enzymes after pumping out. We’ve had to leave tankage for two weeks once with no odor. Follow the book. I can’t say that about some of my friends production boats when we have been rafting up Best ch
Good call on the book -- I will track it down. Hopefully that can explain what that fitting is on my vent line and whether or not its necessary. So you're saying no smaller than 3/4" on the ventline? What kind of hull fitting did you use to connect the vent line to?
Thanks for the suggestions!
 

Diesel Jerry

Admiral
Lite User
Joined
Oct 25, 2015
Posts
9,670
Likes
8,614
Age
43
Location
South Freeport, ME

P18Flirt

Commander
Lite User
Joined
Mar 14, 2016
Posts
312
Likes
370
Location
Northshore MA
First Name
Jeff
Boat Make
Pointer 18 / BHM 28
Last edited:

HeadScratcher

Lieutenant
Joined
Mar 27, 2021
Posts
27
Likes
13
First Name
Tim
This is very helpful -- thanks!
Did you add the access hatch on the top of the tank or did it come with it? I'm guessing that is not a bad thing to have in case you need emergency access.
 

chortle

Rear Admiral
Joined
Mar 7, 2012
Posts
1,112
Likes
858
Location
Annapolis, MD
Boat Make
Herreshoff Coquina, 1972 Jarvis Newman 36, PT11
The white Trident 102 hose is good hose, easy to work with and does not pass odor. Don't underestimate the "easy-to-work-with" part of the equation, most other hose rated for holding tanks does not flex well and is difficult to fit over barb fittings. Shields does make a super expensive lifetime warranty hose called Poly-X, its $25 or $30 a foot. I used a one foot piece to connect my head outlet to the rigid PVC pipe drain for two reasons. One, it mated to the hose barb connection on the bonze fitting on the head outlet and Two, it was going to be filled with fluid 24/7 because the head was about two feel lower than the top of the holding tank. No way around that geometry so I used the best stuff I could get. It was good to work with and zero problems for the past 10 years.

Use solid PVC pipe wherever you can, especially wherever your tank product is sitting inside the tube. You can't make the vents too big. Plastic-Mart will make a custom tank, any shape and size, connections whatever size wherever you want. Well placed vents only smell if you fill the lines with stuff. A well ventilated tank won't smell. Two vents are double plus good.
1638201603013.jpeg

You can use these for thru hull vents, no screens is fine but check them regularly for mud dauber wasp nests as they will clog up the vent and make them not vent.
1638202208588.jpeg
All the advice about downhill is important but difficult to do. Do your best and redouble your efforts to put in a dedicated fresh water flush tank, makes all the difference in the world. It is more expensive to put in a drain with a valve as shown below but it helps when you have to, eventually, remove the tank. It gives you a means to flush it out and plug it shut before you drag it out of the boat.

1638202545179.jpeg
 

P18Flirt

Commander
Lite User
Joined
Mar 14, 2016
Posts
312
Likes
370
Location
Northshore MA
First Name
Jeff
Boat Make
Pointer 18 / BHM 28

HeadScratcher

Lieutenant
Joined
Mar 27, 2021
Posts
27
Likes
13
First Name
Tim
The white Trident 102 hose is good hose, easy to work with and does not pass odor. Don't underestimate the "easy-to-work-with" part of the equation, most other hose rated for holding tanks does not flex well and is difficult to fit over barb fittings. Shields does make a super expensive lifetime warranty hose called Poly-X, its $25 or $30 a foot. I used a one foot piece to connect my head outlet to the rigid PVC pipe drain for two reasons. One, it mated to the hose barb connection on the bonze fitting on the head outlet and Two, it was going to be filled with fluid 24/7 because the head was about two feel lower than the top of the holding tank. No way around that geometry so I used the best stuff I could get. It was good to work with and zero problems for the past 10 years.

Use solid PVC pipe wherever you can, especially wherever your tank product is sitting inside the tube. You can't make the vents too big. Plastic-Mart will make a custom tank, any shape and size, connections whatever size wherever you want. Well placed vents only smell if you fill the lines with stuff. A well ventilated tank won't smell. Two vents are double plus good.
View attachment 121955

You can use these for thru hull vents, no screens is fine but check them regularly for mud dauber wasp nests as they will clog up the vent and make them not vent.
View attachment 121956
All the advice about downhill is important but difficult to do. Do your best and redouble your efforts to put in a dedicated fresh water flush tank, makes all the difference in the world. It is more expensive to put in a drain with a valve as shown below but it helps when you have to, eventually, remove the tank. It gives you a means to flush it out and plug it shut before you drag it out of the boat.

View attachment 121959
I really appreciate this information -- so helpful. I hadn't thought about hard plumbing with PVC. Probably a lot cheaper that the flex pipe. With the hose fittings in the tank -- did you glue those threaded end into the tank or just thread them tight?
I like the idea of the service drain.
I don't know if we have the space in the boat to incorporate a fresh water flush, but, theoretically, we wouldn't need a tank larger than the holding tank, correct (water in, water out)? I'm wondering if I could put a small tank in and "T" of my raw water intake -- so that I could choose either a fresh water or sea water flush?
Again -- this is really good info. A great start for my spring project. I'm in a bind right now because the yard where I store the boat doesn't have a pump out, and we have a little water left in the tank. I don't dare haul it out until it's pumped dry. So I've added some non-tox and will let it sit until the weather warms up. My hope is that once we launch in the spring, I can have our marina pump out, and then I can do all the work at the mooring. If I'm in early enough, they might even let us use a slip for a day or two (so that I have access to power).
If I can pull this one off, my wife will be SOOO happy.
 

Genius

Admiral
Joined
Feb 11, 2016
Posts
6,807
Likes
5,621
Location
Rhode Island
First Name
David
Boat Make
32 Morse Cove
An easy fresh water flush trick is to plumb it into the sink drain. Normally it will pull seawater, if you want fresh water flush...close the seacock and run the fresh water. No chance of cross contamination. Also easy to winterize
 

HeadScratcher

Lieutenant
Joined
Mar 27, 2021
Posts
27
Likes
13
First Name
Tim
Brilliant!
Any insight as to what the fitting is on my vent line (from my original post)? I'm still wondering what purpose this serves and if I need to incorporate another version of this in the rebuild.
Thanks.
 

Diesel Jerry

Admiral
Lite User
Joined
Oct 25, 2015
Posts
9,670
Likes
8,614
Age
43
Location
South Freeport, ME

Latest Posts

Top Bottom