Holding tank to bilge leak?

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Dean Abramson
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Joined: Jul 5th, '05, 11:23
Location: CD 31 "Loda May"

Holding tank to bilge leak?

Post by Dean Abramson »

On the 31, and on our old 25D, the holding tank is just aft of the bilge. Like the bilge, it is part of the hull, not an installed tank. A bulkhead separates the two. I assume some other CDs have this design too.

Has anyone heard of waste leaking from the holding tank into the bilge? I asked this question in another thread, but it was off-topic.

Our bilge reeked last season, and this is my wife's pet theory. I really, really want to believe this is not happening. I have some tests planned...

Dean
Dean Abramson
Cape Dory 31 "Loda May"
Falmouth, Maine
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Phil Shedd
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Location: CD31 Gamblin' #25
Rothesay NB Canada
Membership # 89

smell

Post by Phil Shedd »

Dean

I find it hard to think that the tank would leak because of how strong it seems to be built. Having worked in the # 2 business for quit awhile I am very aware of the smell. The first year we had the boat the bilge had a odor and I could not find it.The next year I removed the bilge pump and cleaned and disinfected the bilge . I also scrub around the top of the tank. Cleaned the inspection cover and the treads on the cover and tank. Checked all hoses and fittings going into the tank. Some fittings were loose as well some clamps were also loose . The one that is used for pumpout looked like it was weeping. That year there was a marked improvement . Over the past years I have replaced all hoses that connect to the tank . ( used the good stuff)I also use a chemical for RV tanks . Seems to make things sweeter but not sure as I have no #2 smell now.

I have to admit I stick my noise into the bilge almost every time I go on the boat to see if it is fresh. Kind of a bilge check thing. Last year was a good year no smell.

Phil
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Ed Haley
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Joined: Feb 5th, '05, 18:45
Location: CD10, Sea Dee Dink

Head odor in bilge

Post by Ed Haley »

Dean:
I can appreciate your concern regarding head odors in the bilge. If you suspect a holding tank leak into the bilge there are tests you can do to confirm such a leak.

However, there may not be a liquid leak after all. It may be an open vent from the anti-siphon valve that allows a release of head vapors into the bilge. Or the hoses need replacing. They don't last forever.

On my CD28, I had an anti-siphon valve that leaked right into the wet closet behind the head. There was no hosing leading the vapors to the outside. I placed a hose from the valve to a vent and that cured the problem.

On my C330, the sanitation hose from the head to the holding tank was cut and spliced with a PCV pipe that allowed smells to enter the bilge. I replaced all the hosing and all was well.

So check all your lines and hoses before you do something as drastic as pulling a holding tank.
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JWEells
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Location: The Typhoon "Valaskjalf" (#1842), in Lake Arrowhead, California.

oops

Post by JWEells »

...
Last edited by JWEells on Apr 25th, '07, 20:33, edited 1 time in total.
Cuique Sententia Mea
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JWEells
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Location: The Typhoon "Valaskjalf" (#1842), in Lake Arrowhead, California.

Reeking of decomposing fuel?

Post by JWEells »

I cleaned out the low part of my keel yesterday, coming to terms with the aftermath of a ruptured fuel tank that had vented all of its diesel into the bilge. It's been taking a while just to get all the ducks in a row. First I had to lift out the tank, which involved sawing it in half as it hung in a hoist. Really a lovely job.

BUT my point is, it took me forever to get the (literally) stinking fuel pumped out of the bottom of the keel. Yesterday, as I finally did the dirty work, I was struck by the stink of scheit. Pure, really fetid, quite old smelling scheit. But that's impossible, since my boat has a closed (composting) head. So it had to be the diesel, turning into something far smellier. It was really foul.
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Russell
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Location: s/v Lady PaulineCape Dory 36 #117

Post by Russell »

Dean,

I had a leaky holding tank when I first bought my CD36. It was not however the tank itsself, it was the hosebarb fitting which the hose from the head attached to which was leaking. I would check all fittings and hoses first, I cant imagine the tank itsself leaking, unless perhaps the boat was once stored for a winter with the tank complely full and not winterized.
Russell
s/v (yet to be named) Tayana 42CC
s/v Lady Pauline Cape Dory 36 #117 (for sale)
liin
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Joined: Jan 9th, '06, 10:59

Leaking holding tank

Post by liin »

Dean:

I purchased by CD33 about 1 year ago. Boat had foul odor when I purchased her but figured this was due to neglect. After sea trial etc. boat was blocked ashore while I did bottom work etc. Bilge had small amount of liquid in it which I thoroughly dried. Next day small amt of liquid in bilge. Repeated process w/same result. Studied problem and detected small trickle that must have been coming from holding tank into bilge. This only occurred when level in holding tank was above lowest level of bilge. Holding tank bottom is deeper than lowest part of bilge.

THis past year I inserted small bilge pump into holding tank (oh joy) and cleaned, and flushed, and cleaned and flushed 26 years of crud. Smell has gone. I have abandoned original tank (but still need to get some final water out of it) and have been thinking through possible solutions too. I've come up with many possibilities including cutting off top and front of tank and install new, abandon v-berth water tank and use as holding, install composting tank, etc. If you figure good solution would appreciate any and all ideas. Storage is limited so don't want to lose any add'l space to new tanks if I don't need too. I'll bet you have a leak! Damon
Oswego John
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Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1

Tracing A Leak

Post by Oswego John »

You can sometimes trace a leak by putting brightly colored food dye in water that is high enough above the suspected area.

This can be done with some deck and port leaks, too

O J
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mahalocd36
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"L" shape

Post by mahalocd36 »

Hi Dean!

If your boat is like the 36, the holding tank area is not just
behind the bulkhead you see, a part of it also goes UNDER the bottom of the bilge. Kind of an 'L' shape, looking from the starboard side of the boat. So when you look directly down at "the bottom of the bilge" you are also looking at the top of the lower part of the L shaped tank.

In our case, the PO or someone along the line had screwed a bilge pump down directly into this "floor''/top of tank. We found
this when we took it out to replace it, those screw holes had an odor coming from them. We did what OJ suggested - food coloring through the toilet and the system, and voila, out those 4 little screw holes. When the pump was there I think it prevented leaks but not odor. Anyways, we solved this by epoxying a piece of starboard down (filling those holes) and screwing the new pump into that instead.

Another thing to check as has been mentioned is the hoses/attachments, and your vent hose. The hose itself might
stink, or be alllowing odor to escape.

Melissa
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Dean Abramson
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Location: CD 31 "Loda May"

Hmmm

Post by Dean Abramson »

Melissa, that is an excellent point. I am fairly sure that our bilge goes all the way down, and the holding tank is not under it at all, but let me double check that.

I personally think our issue was just stinky bacteria-laden bilge water. But I really need to check all the head-related hoses and fittings too.

I really appreciate everyone's input.

Dean
Dean Abramson
Cape Dory 31 "Loda May"
Falmouth, Maine
Dean Abramson
Posts: 1483
Joined: Jul 5th, '05, 11:23
Location: CD 31 "Loda May"

Worst fears realized??

Post by Dean Abramson »

I am not in full panic mode yet, but after spending time on the boat today, I am afraid I think the likely scenario is that the holding tank is indeed leaking into the bilge.

We had left the bilge dry last Sunday, and there has been no rain since then, but when I got there today, there was about an inch of water in the bilge. I have rigged up a long-handled sponge, and I sponged out the water. The bottom of our bilge is full of pits and cracks and places where gelcoat has chunked off. Within minutes, I could see that water was seeping up from these cracks. There was some water in the holding tank, so I fear that's where it was coming from.

I fear that as Melissa says re the 36, there may be a small part of the holding tank below the bilge bottom. If so, the PO may have left water in there, and it froze, and that has cracked the bilge bottom, and thus the problem. OR it is just not a great glassing job on the bulkhead that separates the holding tank from the bilge.

I HATE for this to be the case, but it would explain a lot. We had two previous boats, and there was always some water in the bilge, and it never reeked like this does.

I am wondering if anyone knows exactly how that bulkhead was constructed. Is is solid glass, or cored. Actually, if the 31 is like the 36, then it is really not a bulkhead; rather the bilge is a tub that hangs above the hull cavity which is the holding tank. Does anyone know how they were built?

I found it interesting how many people have written in about stinky bilges; maybe this sort of leak is fairly common.

I put more water in the holding tank, and I am going to go back in a few days, and see if the water levels in each space have equalized. If that is not conclusive, I am going to (yuck) pump out the holding tank, then put in water which has been dyed. Then wait to see if the colored water migrates to the bilge.

Melissa, how did you manged to get down there and do that work? Is the 36 beamy enough that the access is better? On the 31, anything down there has to be done with a long-handled something.

I am wondering about the feasibility of scrubbing the whole bilge bottom with a long-handled wire brush to give it some tooth, then vacuum, then swab with acetone, then just pour an inch or two of catalyzed epoxy down there. Crude, but about all I can think of right now. That, or giving up the holding tank and trying to install one elsewhere.

Not great options.

There is a remote possibility, I suppose, that my port water tank has has a leak (the other two are empty now), but I cannot find any trace of water running down into the bilge, only that water seeping up.

Help!

Dean
Dean Abramson
Cape Dory 31 "Loda May"
Falmouth, Maine
Dean Abramson
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Joined: Jul 5th, '05, 11:23
Location: CD 31 "Loda May"

A thought

Post by Dean Abramson »

Damon, I may be in your boat, as it were.

I am wondering if a collapsible rubber bladder could be inserted right thru the existing tank's inspection port. I guess it would have to be glued in or something, or the pumpout process would try to suck the whole bag out.

I would rather be sailing.

Dean
Dean Abramson
Cape Dory 31 "Loda May"
Falmouth, Maine
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Russell
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Location: s/v Lady PaulineCape Dory 36 #117

Post by Russell »

I would certainly try to reglass or epoxy it and reuse the tank, it would be a shame to just give up the tank as dead space and waste space elsewhere with a new one. On the CD36 access is certainly doable, but uncomfortable as hell, I am 6' and I can touch the bottom of the bilge but my head has to go in too. If access is tighter on the CD31 then you might have a real tough time ahead of you improvising with a pair of long tongs to lay glass mat down and a spreader attached to a handle to smooth out the epoxy, but I think it would be doable so long as your arm can go in and you can see what your doing at the same time.
Russell
s/v (yet to be named) Tayana 42CC
s/v Lady Pauline Cape Dory 36 #117 (for sale)
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Phil Shedd
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Location: CD31 Gamblin' #25
Rothesay NB Canada
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Post by Phil Shedd »

Dean

There are a number of things I would try . I can see how this could happen if holding tank froze once

If I were you having the same boat I would get out my shop vac and clean out the holding tank . I mean really clean it ,hot water commercial disinfecting soap and the lot . Scrub it as best you can. Vacuum it dry Get some heat into it if you can . Even a light bulb will help.

Then do the same for the bilge and get it really dry . Locate the area where you think the leak is coming from and expand the area some. Prep it so you can epoxy it . I would use some light matt with the epoxy.

When you are ready close of the vent tube to the holding tank . But the vacuum hose in the tank and close of the inspection hole with rags so when you turn on the vacuum you will create a vacuum in the tank.

Then do the epoxy work on the area . You will need lots of long sticks and small roller on a pole to do the job. Leave the vacuum running as long as possibly. Once set up apply a second coat.

This how I would try to repair it . Hope this is some help.

Phil
Dean Abramson
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Joined: Jul 5th, '05, 11:23
Location: CD 31 "Loda May"

Post by Dean Abramson »

Phil, that sounds smart. The vacuum in the tank would then pull the resin into the cracks? Is that the idea?

This all seems doable except for the prep. The bottom of my bilge is very rough and uneven, and stained black from something. Knowing the space constraints (it's the opening more than the bilge itself) on the 31, how exactly would you go about prepping that area?

Russell, I am totally with you; I definitely want to continue with that tank, and not give up space elsewhere. This is a blow, but it must be fixable somehow.
Dean Abramson
Cape Dory 31 "Loda May"
Falmouth, Maine
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