Holding Tank problem

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Jun 15, 2010
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My trawler is 13 years old and has 2700 hrs on her.,

I have recently detected effluent in the aft lazerett where the holding tank is located.
The holding tank is plastic
Nylon, I presume.
It appears that the bottom has developed a slight crack although not visable
all fittings look good.
The tank was installed prior to the aft cockpit liner.
Would hate to have to cut out deck to get to tank.
Any ideas would be appreciated
My only though would be to try and seal tank to bottom of hull thereby using the hull as the bottom of the tank.
 
If the bottom is really cracked, I don't see how you could realistically attach and seal it to the bottom of the boat. Not much likes to stick to those plastic tanks long term anyways. So sealing it to the hull would be a big issue. Plus access to all sides of the bottom of the tanks I would think.

I'm guessing there is no way to jack it up and get under it it to weld the crack?

You might be able to cut it open and use it to hold a bladder style holding tank.

Or perhaps cut an access panel in the side and try welding the crack from the inside and then sealing the access panel up.

Just brain storming here. :)
 
My two cents is that Capt. Bill has it right. There are times when the only way to do a job effectively is to do it right the first time, and from your description it sounds like this is one of those times.

For the reasons Capt. Bill states, I think any sort of patch job will be short-lived at best. So I think that the ultimate solution will be to replace the tank. Whether the answer is a bladder tank that might make installation easier, or a new holding tank in a different place on the boat, or simply biting the bullet and taking the smartest approach to getting the failed tank out and a new tank in, I think these are the directions your mind should be focused on.
 
Echo the above but to add, you wouldn't try taping a broken window pane back together and expect it to look and function well. Replacing the broken plastic tank is the only right way to fix it in my opinion.
 
Why not just empty, clean and cut up the tank in pieces where it is and put a new one where you have access room. You can have custom one built to fit any space, thats what we did.
 
Dont know if you boat in or around NDZ's allot but you could cut the old tank apart, then install in its place something like this

raritan3.jpg


Which is a 15 gallon holding tank coupled with a waste treatment system.
 
Dont know if you boat in or around NDZ's allot but you could cut the old tank apart, then install in its place something like this

Which is a 15 gallon holding tank coupled with a waste treatment system.

:thumb::thumb::thumb:

That would be my choice, too.
 
I agree that attempting to patch the tank is a losing proposition. Any of the other suggestions posted are worthy of consideration.
 
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I think by far your best bet is to clean the tank. And find a new location for a replacement tank.

Sent from my Nexus 4 using Trawler
 
I would not remove or do anything to the tank until all other possibilities have be eliminated. Roto molded tank seldom crack. It could be coming from another place and running down the bilge. The Purasan HoldnTreat system is what I have, and I reccomend it. However it is expensive.

Also, is it possible to access the inside of the tank through a hose connection or cut an inspection port? If so, clean it out. Then visually check it, or put clear water with a dye in it to see if that is where the leak is coming from. You could also check it with a boroscope that can be found for around $100.00.

I wouldn't want to cut up a good tank, and still have the problem.
 
Thanks for all the imput. Boat is a Pacific Trawler 37
Holding Tank is 50 gallons and the stringers proclude its removal.
Hate to put a new one, in the salon. LOL
I suppose a couple of cans of radiator stop leak is not going to fix it either. LOL
Will do futher exploration but could not see any sign of hose leakage just a slight amount of aromatic brownish liquid coming from what I believe is the underside of the tank. will keep you all posted
 
If you end up going with a new tank, check Ronco Plastics. They make about 500 different tanks.
 
Don't forget to check the vent hose and connection to the tank if you haven't already. If the tank fills up, further flushing will force effluent out the vent hose and if there's a bad connection or hose leak, that could be the source.

Depending on how much you want to mess around trying to find the source of the effluent, you could pump the tank, then fill it with water and pump it out again, maybe a couple of times until you have reasonably clear water in the tank. Then dump in a bunch of blue dye and see what happens. If you get blue water appearing out from under the tank and you haven't operated any of the other components in the system--- toilet. etc.--- then I guess it's a pretty safe bet you have a tank leak.

Surprising, though, with a plastic tank, unless it's been vibrating against something that wore through it, or if it's a "welded up" tank and a seam has started letting go.
 
Marine sanitation systems---------Where the Affluent meet the effluent.
 
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