I have a 1989 Hunter Legend 37. The holding tank is leaking at the vent fitting on the top of the tank. It is not leaking where the hose fastens to the black barb, it is leaking from under the large thin washer. It is in a very hard place to get any access to do work so I want to be sure of what I do before proceeding. If I move the hose from side to side a bit, the large thin washer lifts off the tank surface. Seems like I should tighten the white plastic fitting, the one that the hose barb screws into, and the one that has the two tabs sticking out of. Is this correct? Should I try to take the fitting apart by unscrewing the fitting with the tabs? I assume there is some sort of mating fitting on the inside of the tank and if I don't retain this somehow, it would drop into the tank. I have not tested for what kind of material the tank is made of but since the fittings appear to be screwed on, I assume it is made of polyethylene or polypropylene. Is there some kind of sealant or adhesive that I could use if I take the fitting apart. Any help will be much appreciated.
leaking holding tank vent
- Thread starter sailordel
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It MAY be salvageable...
But not by doing anything you've described above!
I can't quite tell from your photo whether the fitting is spin welded into the tank or the "washer" is actually a flange that can be resealed. I need enough additional info that it will really be a lot easier for me to figure out how to solve the problem if we can talk instead of swapping a bunch of forum posts or emails. So send me an email (click on my name at the left of this post and follow the instructions) and I'll reply with a phone number.
But not by doing anything you've described above!
I can't quite tell from your photo whether the fitting is spin welded into the tank or the "washer" is actually a flange that can be resealed. I need enough additional info that it will really be a lot easier for me to figure out how to solve the problem if we can talk instead of swapping a bunch of forum posts or emails. So send me an email (click on my name at the left of this post and follow the instructions) and I'll reply with a phone number.
try one of the other fittings
The fittings should all be of the same construction. Can you determine how one of the other fittings attach?
The fittings should all be of the same construction. Can you determine how one of the other fittings attach?
That's what this kinda looks like...
And if it is, it's easy to fix. But before I spend a lot of time typing, I need more information.
Looks like a spin-weld fitting to me, and that it wasn't "spun-welded" very good, and has now partially separated itself from the tank. That isn't a washer, it's part of the female threaded fitting that was welded to the outside of the tank. It covers the actual opening in the tank, and is welded with a heat gun and plastic rod to the top surface of the tank, much like metal is welded with an acetylene torch.
It you're getting sewage or "juice" out from under the washer portion, the weld hasn't held, possibly by overtightening the hose barb fitting that screws into it. At this point, you'll never be able to get it clean enough to re-weld it. The only remaining alternative is to add a mushroom-type through hull fitting in place of it, from the inside of the tank out.
Whoever is doing the job will have to be able to get his hand inside the tank, to install the through-hull fitting. If no cleanout/inspection cap is already on the top of the tank, one will have to be added first. This should give you everything you need to effect the repair:
http://shop.sailboatowners.com/google/custom.htm?vp=37863
It you're getting sewage or "juice" out from under the washer portion, the weld hasn't held, possibly by overtightening the hose barb fitting that screws into it. At this point, you'll never be able to get it clean enough to re-weld it. The only remaining alternative is to add a mushroom-type through hull fitting in place of it, from the inside of the tank out.
Whoever is doing the job will have to be able to get his hand inside the tank, to install the through-hull fitting. If no cleanout/inspection cap is already on the top of the tank, one will have to be added first. This should give you everything you need to effect the repair:
http://shop.sailboatowners.com/google/custom.htm?vp=37863
It Is Fixed!!!
I have owned my boat for 8 years and finally solved a leak problem in my head plumbing. The vent fitting, which is "spin welded" was not properly done, it was only partially welded and subsequently leaked. I removed it and installed a Uniseal which solved the problem. Hallelujah! Guess I will keep the boat!! Attached pictures hopefully are self explanatory. I bought my Uniseals from the following although I suspect they are available from multiple sources.
http://www.aquaticeco.com/search/0/uniseal
The 1/2" Uniseal requires a 1 1/4" hole. The hole in my tank was 1 5/16". A friend with a lathe took a PVC fitting and turned it down to 3/32" greater diameter than a standard PVC 1/2" pipe. The Uniseal stretched enough, although installing the fitting took considerable pressure, so that I have a tight non leaking fitting. This avoided having to drill a larger hole. My holding tank is located under the sink/counter in the head and is near impossible to work on. I had to cut an access hole in the bulkhead between the head and the nav station to get at the hose clamp on the input to the holding tank. I have to completely remove the cabinet in the head to get access to the top of the tank and then I am working though a small hole, only room for one hand. Lots of fun!!
I have owned my boat for 8 years and finally solved a leak problem in my head plumbing. The vent fitting, which is "spin welded" was not properly done, it was only partially welded and subsequently leaked. I removed it and installed a Uniseal which solved the problem. Hallelujah! Guess I will keep the boat!! Attached pictures hopefully are self explanatory. I bought my Uniseals from the following although I suspect they are available from multiple sources.
http://www.aquaticeco.com/search/0/uniseal
The 1/2" Uniseal requires a 1 1/4" hole. The hole in my tank was 1 5/16". A friend with a lathe took a PVC fitting and turned it down to 3/32" greater diameter than a standard PVC 1/2" pipe. The Uniseal stretched enough, although installing the fitting took considerable pressure, so that I have a tight non leaking fitting. This avoided having to drill a larger hole. My holding tank is located under the sink/counter in the head and is near impossible to work on. I had to cut an access hole in the bulkhead between the head and the nav station to get at the hose clamp on the input to the holding tank. I have to completely remove the cabinet in the head to get access to the top of the tank and then I am working though a small hole, only room for one hand. Lots of fun!!
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Is that corrugated hose???
If it is, you need to replace it with sanitation hose...Shields or Trident #148 will do for a vent line. Why use sanitation hose for a line that isn't supposed to carry anything but air? Because any hose that isn't rated for sanitation will permeate very quickly...and you'll be back to chasing the source of odor again.
Except for that, good job!
If it is, you need to replace it with sanitation hose...Shields or Trident #148 will do for a vent line. Why use sanitation hose for a line that isn't supposed to carry anything but air? Because any hose that isn't rated for sanitation will permeate very quickly...and you'll be back to chasing the source of odor again.
Except for that, good job!
Peggy, replaced the vent hose with sanitation rated hose and double clamps and filled tank so that water was in the vent hose, NO LEAKS!! Installed the FERRIELLO holding tank gauge and calibrated it full and empty. Seems to work great. Now I just have to re-assemble all the cabinetry I had to dis-assemble to get some access to the holding tank.
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