Holding tank odour (Peggy ?????)

[artboas]

Ok,,,
I’m sorta stumped
On my fwd holding tank, when you lift the floorboard, you get tank odour.
Not something that loses your lunch, but it’s there.
The tank is plastic, with the following connections

Head in
Mascerator out
Deck fitting out
Vent
Wema guage
4” inspection port
Aux fitting 2” with threaded cap.
I was sure this was a tiny air leak.
My first stab was to run a bead of 4200 around all connections
No luck
So, today I went scientific, in a way that would find a pinhole.

I took the deck vent line, and disconnected it at the hull fitting
Then got a portable 12v inflator, and cobbled together a fitting that connected the inflator to the vent hose
Mixed up a batch of dish soap & water, and methodically went through every fitting.
I would liberally soap it up, briefly turn on the inflator until you saw the tank top expand. The tank was definitely well pressurized at this point.
Not even one bubble. Zero.
I was sure that would find it.
So, after cleaning up the soap, I took a close and personal smell of the outlet deck hose. It definitely has a bad smell to it,
It’s high quality white hose, but I think it’s permeated.
Any comments ???
Next bizarre thing
On the tank there is a mascerator.
In-line to the mascerator is a large on/off red lever valve. Like the stuff you see on hot tubs.
And, of course, the output of the mascerator goes to its own through hull fitting .
What I am finding is that SOMETIMES, if the through hull fitting isn’t closed, the tank fills with lake water. Even though the in-line red valve is closed.
But, this very inconsistent.
As an example,, today after playing “mr bubbly” with my dish soap, I opened up both the through hull & red valve. The tank did not fill up
Another oddity
Water will not stay in the bowl. (It used to) it just drains to tank.
My aft head holds water in the bowl, no problem.
Both tanks are sub floor, and there is an up-loop at the output of both heads.
I can’t imagine this being joker valve, as I have no back flow problems … actually the opposite. The tank won’t keep water in it
To be very clear, I’m attaching a photo of the tank connections

Yes, I’ve checked that the vent isn’t blocked.
I did this by blowing air through the hose once it was disconnected . No restriction

Any ideas ????

 

[baycloud]

I don't have a lot of experience here, but I am working through the same type of problem right now. Bought Peggie's book. Looking at your pic, aren't those the cheaper vinyl hose like Shields 148 that could be permeated? Have you done a permeation test yet?

 

[artboas]

My permutation test was to run a damp rag down the hose & smell it. No smell off the rag, but if you directly smell the hose it stinks badly.
Is there another test I don’t know about?
In any case, I’m pulling the hose.
Not aware of Shields hose.

 

[artboas]

I don't have a lot of experience here, but I am working through the same type of problem right now. Bought Peggie's book. Looking at your pic, aren't those the cheaper vinyl hose like Shields 148 that could be permeated? Have you done a permeation test yet?

Just looked up the Shields hose, and it gets bad ratings for permeation. My hose looks suspiciously similar, and because it’s the cheapest one available, I wouldn’t be surprised that builders use it.
In any case, I’m ripping it out, and that’s that.
I’ll do it once the boat is hauled, as the tanks will be quite clean at that point.
I do a major rinse out at end of season

 

[baycloud]

Just looked up the Shields hose, and it gets bad ratings for permeation. My hose looks suspiciously similar, and because it’s the cheapest one available, I wouldn’t be surprised that builders use it.
In any case, I’m ripping it out, and that’s that.
I’ll do it once the boat is hauled, as the tanks will be quite clean at that point.
I do a major rinse out at end of season

That's what my boat has, and it's definitely permeated. The black rubber hoses, even the one labeled "water" for the macerator aren't. After researching, I'm replacing using trident 102 and raritan saniflex

 

[Peggie Hall HeadMistress]

The cheapest sanitation hose is Shields or Trident (they're identical) #148 flexible PVC. And yes, it's a favorite with builders because it rarely permeates while the boat is still under warranty. That's most likely what you have, but it's hard to know without any markings...it could even be hot tub hose from Home Depot

Permeated sanitation hoses are the most common source of odor INSIDE boat...it's time to replace the hoses--ALL of them, including vent line, toilet to tank, tank to pumpout, to macerator pump via y-valve (use a wye only if it's uphill to the macerator pump) and pump to thru-hull.

Unless you want to do this job every couple of years, sanitation hoses are not something to buy cheap...but you don't have to pay top dollar either. Raritan SaniFlex hose is the only hose I recommend now because it's top-rated, warranted for 10 years against odor permeation and has the added advantantage of being so flexible it can be bent almost as tight as a hairpin without kinking...making most hose replacement jobs a LOT easier. Defender has it for $10-11/ft and sells it by the foot.Raritan Sani / Flex Sanitation Hose at Defender
(I think you and I have talked before about the value of a US shipping address)

Baycloud, Trident 102 is excellent hose, but it has one MAJOR drawback: it's as stiff as an ironing board. I'm guessing you know that and you're planning to use SaniFlex for bends instead of PVC radii...do yourself a BIG favor and go with 100% SaniFlex. It'll cost you a bit more, but worth it 'cuz connecting hose to hose isn't as easy as it sounds.

Artboas....Looking at your photos, I see a lot wrong...starting with all the glop around fittings, around both the hose ends and the threaded ends. There should never be any sealant around hose-barb connections and never anything around threads except Teflon tape. I'm trying to figure out why there's some kind of clear sealant around all all the female tank fittings. Apparently they weren't installed by the tank mfr, but installed by a PO or jobber...no sealant of any kind should have been needed if the job had been done correctly.

We should prob'ly talk about this and the best way to route your hoses. Send me a PM if you'd like to do that .

--Peggie

 

[Richard19068]

Artboas....Looking at your photos, I see a lot wrong...starting with all the glop around fittings, around both the hose ends and the threaded ends. There should never be any sealant around hose-barb connections and never anything around threads except Teflon tape. I'm trying to figure out why there's some kind of clear sealant around all all the female tank fittings.

--Peggie

He said in the original post :

"My first stab was to run a bead of 4200 around all connections
No luck"

 

[Scott B]

Just looked up the Shields hose, and it gets bad ratings for permeation. My hose looks suspiciously similar, and because it’s the cheapest one available, I wouldn’t be surprised that builders use it.
In any case, I’m ripping it out, and that’s that.
I’ll do it once the boat is hauled, as the tanks will be quite clean at that point.
I do a major rinse out at end of season

The hoses are original? I've replaced ours twice now, but we use the holding tank quite regularly. First hose was Trident 101 but always seemed to have a rubber smell to it and since the hose runs under the aft cabin bed, I finally got tired of that smell. Replaced it with Raritan Saniflex this past Spring and have been very happy with zero smells now.

Edited to correct Raritan Saniflex hose...

 

[Peggie Hall HeadMistress]

Shields doesn't make SaniFlex...Their super pricy hose is Poly-X. SaniFlex is Raritan hose.

--Peggie

 

[artboas]

Shields doesn't make SaniFlex...Their super pricy hose is Poly-X. SaniFlex is Raritan hose.

--Peggie

Peggy,

Your opinion on Vetus hose?
Looks like it’s actually wrapped in some sort of clear plastic?

 

[Peggie Hall HeadMistress]

Vetus sanitation hose is decent...never noticed it looks plastic covered. It's double walled hose that's similar but not quite as odor resistant or flexible as Raritan SaniFlex.

--Peggie

 

[artboas]

Vetus sanitation hose is decent...never noticed it looks plastic covered. It's double walled hose that's similar but not quite as odor resistant or flexible as Raritan SaniFlex.

--Peggie

Thanks so much!