Can't get sanitation hose off diptube

Jun 18, 2022
9
Beneteau 351 Bellingham
I noticed that the diptube fitting to my holding tank is not tight on the threads, I can turn it slightly clockwise and counterclockwise by twisting the sanitation hose. It is fixed vertically because of the threads (it can't rise up and down) but I'm worried about the seal with the holding tank.

After removing the hose clamps, it seems impossible to get the hose off - I've tried using a heat gun on the highest setting for about 10 minutes and still can't get the hose off.

Any suggestions?

If I can't get it off, then I'll probably have to cut the hose off, spend the money to buy a new one, and redo the whole pump out line. Alternatively I could simply caulk the threads but that doesn't feel like a solid solution.

IMG_3192.jpg
 
Mar 20, 2015
3,242
C&C 30 Mk1 Winnipeg
White section looks like a rotating coupling ?
If so you can simply turn it in and out as required. The male black barb fitting, if tight into the female portion of the coupling may need to be loosened ever so slightly to let the coupling joint rotate easily.

When you say caulking threads, do you mean, just squeezing caulk into the area and hoping it will work ? It won't. Caulk.works as a gasket between components, not just shoved again't a gap. Don't use silicone. You would need to disconnect the coupling and use Teflon tape/liquid on the pipe thread.
 

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Jun 18, 2022
9
Beneteau 351 Bellingham
White section looks like a rotating coupling ?
If so you can simply turn it in and out as required. The male black barb fitting, if tight into the female portion of the coupling may need to be loosened ever so slightly to let the coupling joint rotate easily.
I believe the top white piece is glued, which could be part of the problem. I wasn't able to rotate that separately from the bottom white piece. I could try again with a pair of wrenches.
 
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Mar 20, 2015
3,242
C&C 30 Mk1 Winnipeg
believe the top white piece is glued, which could be part of the problem
Even if the coupling is glued together, you may be able to tighten the white fitting into the tank and then hold that while tighting the black barbed fitting.

That assumes the the hose can turn on the black fitting, when the clamps are loose. Normally it will, even if the barbs prevent you from removing it
 
Jan 4, 2006
7,271
Hunter 310 West Vancouver, B.C.
The hose can't turn on the black fitting, even after using a heat gun... I wonder if it was glued on?
Now there's a revolting thought. I certainly hope not.

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Something that may be causing an additional problem is that the barb fitting is actually a PVC threaded nipple. This may have cut into the hose over the years of exposure.

That hose is an SOB to work with as it is wire wound and stiff as hell. All I can suggest is to disconnect the hose on the other end, push and pull it out a window, and then unscrew it right where the hose goes over the nipple. Grab the PVC with pump pliers or a small pipe wrench. Something has got to come out. Don't damage the hose as it's worth its weight in gold.

I would recommend removing that entire haywire assembly and installing a proper MIP X BARBED adapter and eliminating all possible leaks.
 
Mar 20, 2015
3,242
C&C 30 Mk1 Winnipeg
I would recommend removing that entire haywire assembly and installing a proper MIP X BARBED adapter and eliminating all possible leaks
+1.

What Ralph is saying, is use a single barbed fitting on the tank instead of the multiple ones you have. Every joint is a possible leak spot. The less fittings the better.

The previous owner likely got the fittings at a home store like home Depot and they didn't have a single price that would work. So they used multiple adapters.

A good supply store will have a single fitting that does the whole job.


Depending on the age of the hose and your budget. I would just redo the whole thing. But I hate spending time fixing old stuff when I can just replace it and never worry again. I just went through that with our boat. The survey said the hoses were ok. They looked ok visually...They weren't. the fuel ones were an explosion or fire waiting to happen.I suspect most of them were original from 1978.

Explains why the boat had a nice smell of gasoline and poo the first spring. :poop::yikes:

I used "Green line Hose" as my main supplier. Much better than dealing with a marine dealer and their pricing. They sell ABYC rated stuff. I had to source the sanitation hose from our local marine supplier.
 
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Oct 26, 2008
6,290
Catalina 320 Barnegat, NJ
I was about to say that I usually just cut the hose because at that point I'm going to replace it anyway. But then I read @JBP-PA above and I have to admit that's genius!
 
Mar 20, 2015
3,242
C&C 30 Mk1 Winnipeg
Cut thorough the black threaded nipple. They are cheap. Then you can unscrew the nipple from the hose and from the fitting.
The fittings are apparently loose at the threads and can already turn a bit.

But If the barb fitting won't turn inside the hose now, with a pipe wrench holding the fitting, I can't see that improving after you cut the threaded area

I did get a very stubborn barb out once, from recently new wire reinforced hose, by using a hacksaw blade to cut a groove in the inside of the barb, just enough to make it flex and therefore easy to remove, without cutting so far as to damage the hose.
Much depends on the wall thickness, the barbs, and stiffness of the fitting.
 
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Dec 25, 2000
5,934
Hunter Passage 42 Shelter Bay, WA
Before I would do any drastic measures, such as cutting, I would place a channel lock style pliers on the black part to keep it from turning and another pair to twist the hose off. See if that works.
 
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Mar 20, 2015
3,242
C&C 30 Mk1 Winnipeg
I would place a channel lock style pliers on the black part to keep it from turning and another pair to twist the hose off
100% :beer:
That is effectively the point of post#4

@sydneybadger mentioned trying 2 wrenches, but I assume that meant pipe wrench or hopefully.. channel loks.

Personally I would check the date code on the hose, and if needed, get a new hose, and reduce the number of fittings. I wonder if it is actually sanitation hose. I am betting not. @Peggie Hall HeadMistress may have a better eye, or larger screen.
 
Dec 25, 2000
5,934
Hunter Passage 42 Shelter Bay, WA
but I assume that meant pipe wrench or hopefully.
Although I do have two on board, I've never had much luck with pipe wrenches on the boat. I've found channel lock style more useful in the OP's application. Hoses that have been clamped on barb fittings for years can be difficult to remove. A twist with channel locks have worked for me a number of times.
 
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Mar 20, 2015
3,242
C&C 30 Mk1 Winnipeg
I've never had much luck with pipe wrenches on the boat. I've found channel lock style more useful in the OP's application
100%

I hate pipe wrenches at the best of time. On a boat with limited swing they are even worse. Until a few years ago, I didn't realize how big true channel lock brand pliers can be. They are a godsend for many jobs.

I have had some luck with the hose pick tools meant for automotive use. They work great and while they aren't really designed for barbed fittings, they can still do a good job on getting a hose apart from the fitting. I have both homemade and factory made versions.
 
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Jan 7, 2014
451
Beneteau 45F5 51551 Port Jefferson
Try a radiator hose pick to break the seal with the barbs. Harbor freight sells them.
 
Jan 4, 2006
7,271
Hunter 310 West Vancouver, B.C.
When you are finally ready to assemble this knuckle buster with the old hose or brand brand new hose, take a hint and coat the inside of the hose and outside of the barbed fitting with a definitely non-petroleum grease such as SuperLube before assembling.

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The joint stays lubed and no worry about it coming apart with double clamping. The worst hose joint on the boat is the one on the water/exhaust mixing fitting. I used to remove everything and take it home to put it in the big vice to break that joint. Now it comes off, in place, with only slight hand effort.
 
Jun 18, 2022
9
Beneteau 351 Bellingham
Update:

I was able to do as @Ralph Johnstone suggested in #6, which was to disconnect the other end of the hose from the thru-hull, and use the whole hose to unscrew the fitting from the tank. The whole piece came off, including the diptube.

Then I was able to use a lot more leverage (and full 360-degrees with the heat gun), and get the hose off.

The diptube and white PVC are glued together in one piece. It's actually in good shape and measured to stop 1/2" from the bottom of the tank. Pic attached. The black fitting is a male barbed hose adapter.

The hose is a premium sanitation hose #101-1120, which is also in good shape. I almost cut it, and didn't, thanks to the good advice here.

While putting back together, I discovered the waste thru-hull had lost it's seal with the deck and a couple of the screw holes were stripped, letting water drip inside... It seems like whenever I do a job, I always find one or two more!

IMG_3276 Medium.jpeg
 
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