Head smell investigation

[mark porter]

Hi all - I purchased an H31 a couple of years ago and it had a stinky head. I replaced ALL the hoses, and the smell subsided 80%. But there is still a gassy smell that accumulates when the boat is buttoned up. Not sure if I might have a leaky holding tank access hatch, or a cracked tank, or a malfunctioning syphon preventer. As I am tackling easiest options first, can anyone tell me if the syphon preventers fail? It seems to have the original 1986 model, so I wondered if that might be a source of the smell. If anyone had any thoughts on the syphon preventer or any other possibility, I'd like to hear them.

 

[Sailm8]

Have you checked the vent? When mine was clogged it increased the smell. Also are you flushing all of the poo out of the lines with each flush? I carry jugs of fresh water and only use fresh to flush never salt water. I try to use enough that only fresh water is left in the line. I also pour fresh into the bowl and flush when we leave the boat. Making sure the trap has fresh water in it.

 

[MLampner]

All of the suggestions made are good. Saltwater and to a lesser degree freshwater have millions of microorganisms in the mix. When cut off from oxygen and food they too die and can add to the smell so flushing with freshwater, even gray water from dish washing is a plus.

Peggy the former head mistress of this site also recommended and we have had great success adding an oxidizer like Oderless to the last flush of the day. The tank produces the unpleasant oders when anaerobic decay takes place in the tank. A clean vent line add adding oxygen helps by favoring aerobic depcomesition and goes along way to reducing unpleasant reminders of human by-products.

 

[mark porter]

All good suggestions. On further investigation, I rubbed my hand along the inside surface of the Fiberglas space under the V berth, and my hand came back smelly. This isn't even part of the tank, just the inside of the bulkhead under the V berth. Seems like a difficult place to scrub as I only have access through a little 12" hatch. But I'm going to give it a try, as well as any other surfaces under the V berth that I can get a soapy scrub brush onto. I will probably follow up with vinegar after that and let it sit all winter.

 

[Keith13315]

There is a space between the liner and the hull that accumulates water and it sits and ferments. After we bought our boat I learned about it. The weep hole into the bilge is to small and high to allow the water to drain into the bilge sump. I used a dremel tool and cut it lower making it look like a key hole. If you pour vinegar into the bow under the vee berth access door it will run into that area, let it sit over night (the boat will smell like a salad) rinse with fresh water add a bit of vinegar again and let it be. Now a couple of times a season I add vinegar rinse add a bit more and let it be the boat smells much much better. You may need to do it rinse a couple of times because a bunch of ich came out.

 

[IH82BL8]

I'm chasing the same issue on my H31. There was a very small leak last summer where the big hose goes into the holding tank. Whatever leaked out ran down between the liner and the hull under the head but hasn't made it to the bilge I think it's at the centerline of the boat just forward of the open floor grates. The liner is raised in the bottom of the vanity (where the head intake seacock is located). In the very near future I plan to drill through the liner in that area with a 6" hole saw so I have access to whatever in is that void and then install a deck plate. That will give me immediate and future access to the void for cleaning purposes.

Observations on locating and treating the source of the smell:
-It's not my holding tank. The inside of the tank smells better than the inside of the cabin.
-I've poured fresh water with vinegar, bleach and detergent down between the hull and liner below the v-berth. That takes away the smell immediately, but it always eventually comes back. That makes me think that when the water covers the surface of whatever is making the smell, it insulates it from the air in the cabin.
-It seem like most of the water I pour in makes it to the bilge.

I'll report whatever I find.

 

[mark porter]

It sounds to me like we have a similar issue. I was thinking of plugging the limber holes, flooding the void space with vinegar between the liner and hull, the unplugging 24 hours later and rinsing. I can't get to it for a week or so, but will report back findings (probably smell like a huge pickle!) when I do. Stay tuned.

 

[mark porter]

Just an update. I had great success by making up a vinegar/water solution (1:3 ratio ). Dumped it into the hatch under the vee berth and let it sit for a week, then pumped out using bilge pump. Voila! Stink is gone. This will be a spring/ fall routine for me now