Holding Tanks?

Newbie sanitation question:

I hope this story doesn't go on too long, but I want to get all the boring details incase some detail is unexpectedly important.

Bought the boat in November of 2014. Haven't gone on any extended trips so far so have not really used the black water tanks. But the PO didn't empty them before handing the boat over. I've been cleaning the bilge trying to eliminate a greasy odor which, so far I have not been successful at.

The tanks are Stainless Steel. The forward one has an accessible inspection port. The aft one is under a fixed deck and no obvious inspection port.

After pumping the tanks at a waste station and getting all the nasty water out of the bilges I noticed that the aft SS tank did not empty. It has a solid thudding noise when you bang on it where as the forward SS tank sound hollow and echoes. This gave me some things to consider. Is my venting clogged and not allowing the sludge to be sucked out? This full aft tank is the one the macerator pump is connected to. Not sure how this works in a situation where you would want to pump the forward tank overboard? But the macerator is not functional. I have a replacement pump ready to go, and would love to change it but wouldn't dare if the tank is full of coarse!

Since I haven't come up with a game plan I moved onto another project. In the meantime, I noticed that there is an inch of water in the bilge again under the waste tanks and a black residue floating around in it. It's not the freshest smelling either! Now I'm wondering if there is a leak in that tank?

So I'm wondering about how to proceed? I'm on a budget, so need to explore least expensive possibilities first. Looking forward to some input. Thanks!

First, stainless steel (or any metal) is a terrible thing to make holding tanks out of. The contents will eat away at metal and start to pinhole them sooner rather than later. I know--- our boat had a stainless tank for the aft holding tank when we bought it.

The best material for a blackwater holding tank is plastic or fiberglass. When the stainless tank in our boat began to pinhole within a year of our buying the boat, we replaced it with a one-piece, vacuum-molded plastic tank that we got through Marine Sanitation in Seattle.

With regard to not being able to pump a tank out there can be several reasons for this. One is clogged pump-out tube, the tube that extends down to the bottom of the tank and is connected to the plumbing going to the pump-out fitting for that tank.

If the tank has a metal pump-out tube, very possible if your tank is metal, eventually the contents of the tank will eat through the tube same as they wll eventually eat through the tank itself. As soon as a hole has been eaten through the tube, the tank will be able to be emptied only to that point. As soon as the hole is exposed to air, no more vacuum. So the capacity of your tank is reduced to the tank volume above the highest hole in the tube. This is why the ideal material for a pump-out tube is PVC or some other plastic material.

The only reliable way to check for a plugged or eaten-away tube is to pull it out of the tank and inspect it.

Now it's possible that the tank vent could be plugged, but this usually means you will start getting tank contents pumped out and then the flow will trickle to a stop as vacuum builds in the tank. An easy way to check a vent tube is to force water up it through its through-hull in the hull. Stick a garden hose into the opening and turn on the water. If you hear water entering the tank inside the boat, the vent is clear.

Since you seem to be experiencing tank problems including a leak now, I suggest you bite the bullet and get rid of both stainless tanks and replace them with plastic tanks. Because it's just a matter of time before those stainless tanks will fail in ways you do not want them to be failing inside your boat.

Now the short version.


What he said.


And those pictures are further proof that some people should not be allowed to build boats ever again.

Capt.Bill11 said:

Now the short version.


What he said.


And those pictures are further proof that some people should not be allowed to build boats ever again.

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Feel free to add detail to your building critique so I know what to change and what it should look like when I'm done fixing what I don't know is wrong yet.

I agree, Capt Bill give the guy a break! He is here looking for education (like we all are), not to be thrown under the bus.....We may want to be a little more user friendly, after all this isn't THT.

Teg, A good source of information on how to deal with boat odors is this book by Peggie Hall.



Peggie may pick up on your post and give you some help here.

Like the guys said, metal tanks don't seem to last long when holding black water.

A good source of plastic tanks is a company called Ronco. No, they don't sell the Vegimatic. Ronco Plastics - Marine Water Tanks, RV Water Tank, Auto Detail Tanks, Water Tanks

Hoses can also become saturated and give off an odor. The test for that is to wipe your hoses with a clean damp rag then sniff the rag. If that's the problem, the fix is to replace the hoses.

I'm missing something in the photos.

How are the two tanks connected together?

ksanders said:

I'm missing something in the photos.

How are the two tanks connected together?

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I'm not sure. It's very difficult to see where all the hoses are going. It's not a very accessible area. I thought they must be connected since there is only one waste deck fitting.

Are you sure both are blackwater tanks? That would be very unusual.

Sailor of Fortune said:

I agree, Capt Bill give the guy a break! He is here looking for education (like we all are), not to be thrown under the bus.....We may want to be a little more user friendly, after all this isn't THT.

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How am I throwing the OP under the bus? He did not build the boat. I'm just commenting on the fact that the original builder used SS for holding tanks. And the way they are plumbed.

HopCar said:

Hoses can also become saturated and give off an odor. The test for that is to wipe your hoses with a clean damp rag then sniff the rag. If that's the problem, the fix is to replace the hoses.

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As I recall, per Peggie, the correct way to perform that test is to use a hot wet rag/towel, place it on the hose and let it stay there overnight.

But just looking at those black hoses in the picture Id say it's time to replace them.

Unless they are not really being used as black water hose.

From your pictures it looks like the aft tank is not connected to the forward one. And as the previous poster said, it would be very unusual to have two holding tanks connected together.

I suspect that one serves the forward head and the other one serves the aft head. The aft tank does not have a deck pump out dip tube, only the macerator pump.

So how do you empty the aft tank? I went through almost exactly the same problem with my friend's 30 year old T/T. The hose to the macerator tank was full of crud and the deck pump out fitting was corroded shut. We pulled off the macerator hose and pushed a water hose inside to back flush the crud. Fortunately it wasn't very full but it did make a hell of a mess.

But in your case it looks like the hose is long enough to pinch shut with a C clamp. Then you can pull off the macerator pump and replace. Open the clamp and if you are real lucky the macerator pump will pump out the tank. If you are not so lucky then you have a couple of poor choices:

The simplest but by far the messiest is to just pull off the hose at the nozzle to the tank and let it dump to the bilge. Pump out the mess with your bilge pump. Flush with water and then use a couple of pints of hydrogen peroxide which will help kill the odors. Then wash the hose out with a garden hose and replace the macerator pump.

The more complicated way is to cut an access port in the top of the tank with a sawsall or similar. Then you can drop a pump out hose down in the tank to empty it. Cover the hole with a stainless plate screwed and glued down with 5200. Remove the macerator hose and clean out the gunk in it and replace the pump.

One benefit to this approach is that you may be able to install a pump out dip tube to the stainless steel cover plate.

And as others have said, stainless steel will sooner or later fail. Roto molded polyethylene tanks by Ronco or others is the permanent solution.

David

"But the macerator is not functional. I have a replacement pump ready to go, and would love to change it but wouldn't dare if the tank is full of coarse!"

A non working macerator is hardly unusual.

If it is above the tank, it will loose suction from stuff stuck in its valve system. R&R .

The preferred location well below the tank sometimes just gets stuck.

Be sure all valves are open and if its 12V use a battery and starter cables to give it a real blast of DC,.

After you either dump, or search the hoses and valves so it can be emptied when you replace the pump install a VALVE , so the pump can be replaced easily.

AS cheap waste pumps get overloaded easily I would install a 120V unit and a cheap inverter to power the unit.

Plan B is to use a higher quality pump like a 120v Obendorfer rather than a cheapo.


If a new tank is in the cards get a low 3 inch discharge spun in the plastic.

Then an RV quality shut off valve can be used , so disconnecting a cheap pump to clear it will not be much of a bothe.

Dupree makes great RV valves.. and 1/4 turn disconnects.

I'd pull off the top white hose going into the back tank (have a bucket or catch basin ready) maybe you will be able to look inside with a flashlight to see if it is full. Try to get a smaller suction hose down in there to pump it out into buckets.
How big is the fwd tank maybe you can live with it alone and eliminate the aft, possibly leaking, one. Leave it in place, or take it out, replace it later or not.
Why are some of the hoses wrapped in what looks like saran wrap? maybe that is where the odor is coming from?
Good luck with the project!

teqd...

Looking at the photos I have a few questions & suggestions...

It appears that the fwd tank was constructed w/ a sm & lg bolt on access plate / ftg on the top? If so I'd remove the lg one & know for sure what is on the inside - flush the head & observe - pump out & observe. I'm guessing the lg is an inspection / cleaning access and the sm may be for a level gauge?

Does the aft tank have similar access? - do the same

Bottom line try to figure out how these tanks are connected to your head(s), deck pump out ftg and each other?

If these are truly separate tanks serving 2 heads you will probably bave to ad a 2nd deck fitting to allow pump out of the 2nd tank.

It looks like the aft tank macerator line terminates w/ 1-2 elbows (or trap) at the tank? Isn't real clear in the photo so I'm guessing a little... if so it may affect the macerator ability to draw - Can you disconnect this hose at the macerator pump and connect it to a temporary hose that would allow suction pump out? The height of the hose should minimize any spillage if the tank is only partially full.

If you suspect a blocked vent - why not remove the vent hose at the tank and see what happens when you attempt a suction pump out?

If these tanks are removable by removing the hatch support I'd be trying to get them out to replace & replumb them as mentioned above.

Greetings,
Mr. t. Oh poop! Well, how I would proceed is:
1) Line the bilge area under and forward of the AFT tank with several layers of newspaper making sure you layer 8"-10" up the sides of the hull and as far under the tank as you can up to the edge of the bottom of the forward tank.
2) Get a bag of Kitty Litter and spread a generous amount on top of the newspaper.
3) Put on HazMat suit, rubber gloves, EYE PROTECTION and gas mask (OK, kidding about the HazMat suit but NOT the eye protection).
4) Remove upper hose on aft tank.
5) Suck out ???? with shop vac to the best of your ablilities (may have to affix smaller hose.
6) When you think you've removed the ???? to the level of the bottom tube, remove bottom tube.
7) Kitty Litter is to hopefully contain any oopsies and newspaper is to limit spread of Kitty Litter.
8) Vacuum up Kitty Litter when finished.

tegdesign said:

I'm not sure. It's very difficult to see where all the hoses are going. It's not a very accessible area. I thought they must be connected since there is only one waste deck fitting.

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OK, is the deck pumpout and the macerator pump both connected to the same tank?

If so, how is the other tank going to empty.

As a single data point example, our boat has two holding tanks. The one in the engine room is for the forward head. The one in the lazarette is for the aft head. Both systems are totally independent of each other, with their own pump out fittings, macerator pumps for overboard discharge, and so forth.

While never say never, I would be surprised if a boat in the size range that we're talking about had two holding tanks plumbed together, particularly with only one pumpout fitting. There would have to be some way of moving contents from one tank to the other.

The suggestion made earlier to make sure both tanks are indeed holding tanks is a good one unless you already know for sure that both tanks are blackwater holding tanks. The only other reason to have a tank like this onboard is as a fresh water tank. A large hose running into the tank could be a fill hose from the fresh water deck fitting.

In any event, the problems you are starting to experience now provide a good incentive for replacing the metal holding tank(s) and replacing with a good quality plastic tank. And if you do, in fact, have two holding tanks, this could also provide the opportunity to make both systems independent of each other so each tank has its own pump-out fitting.

Marin said:

As a single data point example, our boat has two holding tanks. The one in the engine room is for the forward head. The one in the lazarette is for the aft head. Both systems are totally independent of each other, with their own pump out fittings, macerator pumps for overboard discharge, and so forth.

While never say never, I would be surprised if a boat in the size range that we're talking about had two holding tanks plumbed together, particularly with only one pumpout fitting. There would have to be some way of moving contents from one tank to the other.

The suggestion made earlier to make sure both tanks are indeed holding tanks is a good one unless you already know for sure that both tanks are blackwater holding tanks. The only other reason to have a tank like this onboard is as a fresh water tank. A large hose running into the tank could be a fill hose from the fresh water deck fitting.

In any event, the problems you are starting to experience now provide a good incentive for replacing the metal holding tank(s) and replacing with a good quality plastic tank. And if you do, in fact, have two holding tanks, this could also provide the opportunity to make both systems independent of each other so each tank has its own pump-out fitting.

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The question about weather both tanks are black water tanks is a good one. The reason I thought they were both black water and connected was that I have a central shower sump that both showers drain to then is pumped overboard. The Kitchen sink drains directly overboard, and although I don't know it for sure, I would have thought each sink would be the same arrangement, overboard. I'll have to confirm that next time I'm at the boat.

My water tank is under the aft cabin bed in the opposite end of the boat.

I think I have some home work to do to answer these questions!

Thanks ALL

ksanders said:

OK, is the deck pumpout and the macerator pump both connected to the same tank?

If so, how is the other tank going to empty.

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The macerator is only connected to the aft (full) tank. As for the deck pumpout, I don't know. I can't tell which hose that is. Do they ever connect more than one tank to a deck pumpout because I only have one deck pumpout fitting, and I know that fitting is at lease connected to the forward tank that is now empty.

"Do they ever connect more than one tank to a deck pumpout because I only have one deck pumpout fitting,"

Sure , but then there will be a 3 way valve to close off the empty tank and suck out the other.

Big PIA , but you will need to use a marking pen to keep track and do a drawing of your tank plumbing realty.

Steve said:

I'd pull off the top white hose going into the back tank (have a bucket or catch basin ready) maybe you will be able to look inside with a flashlight to see if it is full. Try to get a smaller suction hose down in there to pump it out into buckets.
How big is the fwd tank maybe you can live with it alone and eliminate the aft, possibly leaking, one. Leave it in place, or take it out, replace it later or not.
Why are some of the hoses wrapped in what looks like saran wrap? maybe that is where the odor is coming from?
Good luck with the project!

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The saran wrap? Some one thought it was a good idea to leave the plastic wrapping on all the hoses in the boat! UH!!!

I see, I though maybe a prevouis owner might have added it.

tegdesign said:

The saran wrap? Some one thought it was a good idea to leave the plastic wrapping on all the hoses in the boat! UH!!!

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Saran Wrap is imprevious to odor. So it's a legitimate temporary fix to an odor problem from a permeated sanitation hose. Peggie Hall often recommended wrapping a hose or section of a hose in response to forum participants asking how to deal with odor problems.

But, as she always stressed, it is NOT a permanent fix and should never be thought of as such. The only permanent fix is to replace the hose. Or replace the hose run with something that isn't hose, namely PVC tubing.

The plumbing run from our aft toilet to our aft holding tank by its nature holds waste in the aft end of the run before it goes up and into the tank. The original hose had permeated and was a problem, located as it is under the aft berth.

So we replaced the aft run with a length of PVC, which will never permeate. For the flexible bend from the lower pipe to the upper pipe that goes to the holding tank we reseached and found the most permeation-reisstant hose on the market and used that. It won't remain odor free forever but it should be okay for a number of years.

PVC plumbing must be protected from vibration or it will eventually crack. So the connections at each end of a PVC run should be a section of hose to "suspend" the PVC run. In a well-designed plumbing run, the sections that are hose will never be a collection point for effluent. If the hose is essentially empty other than when effluent is passing though it, it will be a long, long time before odor permeation becomes a problem.

Get out the saw and get that stuff out of there, that is what I did. Have not been to a pump put in 2 years! Forward head is a Type I and the aft head is a composting head. Our boat smells much better now.

First thing I did after reading through many posts here was to buy Peggys book

then I took out every line hose vent pump and replaced in the entire system

then after fixing each toilet 3-4 times in a year I replaced them

so now the only thing old in my system is the tank and that is on the list

the greasy smell in the bilge I have become a expert and cleaning the PO cam by the other day and asked how do you make your boat smell so good

made me feel great

I have a Heritage East 44 with a 300 gallon FW tank under the bed in the aft and another 75 Gallon FW tank about two feet forward of my waste tank - similar to your picture. I also bought the boat form someone who did not empty the tank and it would not empty fully after sitting mostly full for three years. It took a very helpful dockhand several hours a day for several days to fill with fresh water and pump out - one day he did it 36 times over several hours. Eventually the water flushing worked to clear the solidified goop from the tank and it now empties completely. As to having only a macerator on the tank to empty I know that here, in the Chesapeake, you would get a several thousand dollar fine each time you were boarded as there is no way to show that the waste does not go overboard. Every time I have been on a boat that was boarded, usually for routine checks, they check the bilge for oil, head "y" valves, and flares. They usually find something as most folks don't update flares often enough or change oil pads often enough.

"Eventually the water flushing worked to clear the solidified goop from the tank"

The fast way to do this is to access the tank fill and shove in 30 lbs of ice cubes and go for a ride.

The more wakes you find , the quicker the fix.

tegdesign said:

The saran wrap? Some one thought it was a good idea to leave the plastic wrapping on all the hoses in the boat! UH!!!

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Saran Wrap has long been known to be a very effective "bandaid" on stinky hoses. ONLY Saran, no other brand, will work. In fact, I used it on my own boat...I'd replaced the entire system including all the hoses less than 3 months earlier on a boat I was restoring ...incredibly, the hoses had already permeated. Rather than REdoing work when a temporary solution was available and so much more needed to be done, I trotted over to the convenience store across the road from the YC and bought a roll of Saran Wrap...secured it with eclectrical tape. It turned out to be almost a year before I got around to re-hosing...not a trace of odor meanwhile...which is the only reason I didn't do it sooner. Saran Wrap can make it possible to put off replacing hoses till the weather cools off instead of having to do it in the heat of the summer to make being aboard bearable.

As I recall, per Peggie, the correct way to perform that test is to use a hot wet rag/towel, place it on the hose and let it stay there overnight.

Not quite, Bill...Hot wet rag only needs to remain on the hose till it cools. Clean off a section of hose--to eliminate odor from another source that's attached itself to the outside of the hose...and use a CLEAN rag for each piece of hose tested.

I've spent countless hours cleaning and crawling around in my bilge, trying to determine where each hose went and where each wire went. There really is no other choice, you have to know where everything goes or you'll never be able to troubleshoot anything. It's a nasty, time consuming job and sometimes you have to do surgery on your boat to get things right. Once you've found all the problems and fixed them you'll be a lot more confident in your boat. Dirty, tired and frustrated but more confident in your boat!