I am in the process of replacing the sole in the main cabin area of my H34. Of course I had to take all the settees out, which gave me easy access to the holding tank. While there, I figured I might as well replace the hoses since they are the black rubber kind and upon inspection I noticed some cracks. Previous owner had used some type of caulking to seal off the screwed-in 1½" elbow of the pump-out outlet (looks like PVC grey plumbing style). The vent outlet was cracked in the thread area and had also been caulked. Tank itself seems A-OK and there were no leaks. I want to replace the vent outlet. Current one (light green, looks like ½" threads) seems to be bonded with tank material. Any suggestion for a fix ? Also, should I caulk when I install the new 1½" outlet. I have the tank out of the boat so I can easily work on it. Thanks for the ideas.
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david lewis
plumbers putty
I am guessing that what you refer to as "calking" is actually plumbers putty. Plumbers use this to seal threaded fittings so they don't leak. At the bottom of the threads there is a very small clearance which can provide a leak path if not sealed. Threads bear on the pitch diameter and not at the "pointed" part of the thread leaving a small space between the tips of the male threads and the root of the female thread. A cleaner and easier method is to use teflon tape to seal these threads. Wrap many wraps of tape around the threads and then screw into the tank. The teflon is very soft and pliable and seals the fitting just like putty. The difference is it will not harden and crack with age so when you take it apart it will be easy to remove. You can get teflon tape in the pluming dept. at any hardware store. dave
I am guessing that what you refer to as "calking" is actually plumbers putty. Plumbers use this to seal threaded fittings so they don't leak. At the bottom of the threads there is a very small clearance which can provide a leak path if not sealed. Threads bear on the pitch diameter and not at the "pointed" part of the thread leaving a small space between the tips of the male threads and the root of the female thread. A cleaner and easier method is to use teflon tape to seal these threads. Wrap many wraps of tape around the threads and then screw into the tank. The teflon is very soft and pliable and seals the fitting just like putty. The difference is it will not harden and crack with age so when you take it apart it will be easy to remove. You can get teflon tape in the pluming dept. at any hardware store. dave
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Claude L.-Auger
Definitely caulking
and not plumbers' putty. Clear bathroom style caulking ad sold in the hardware stores. Can I use teflon tape as the tank is made of some sort of plastic ? I am afraid of breaking the pum-out outlet threaded fitting. In fact it might be how the vent outlet threaded fitting got split.
and not plumbers' putty. Clear bathroom style caulking ad sold in the hardware stores. Can I use teflon tape as the tank is made of some sort of plastic ? I am afraid of breaking the pum-out outlet threaded fitting. In fact it might be how the vent outlet threaded fitting got split.
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david lewis
Teflon tape
When I bought my boat the previous owner had a direct discharge set up with no holding tank...they had removed it but gave it to me with the boat. I reinstalled it correctly and legally with a macerator and a deck discharge with a y-valve, so in no discharge areas I can use a pump out boat, and out at sea I can empty the holding tank using the macerator. Anyway I used teflon tape on all the fittings with no leaks and no damage, again the teflon is soft and pliable and since teflon is inert (non-reactive) it will not cause any problem with the plastic on the tank that I know of. dave
When I bought my boat the previous owner had a direct discharge set up with no holding tank...they had removed it but gave it to me with the boat. I reinstalled it correctly and legally with a macerator and a deck discharge with a y-valve, so in no discharge areas I can use a pump out boat, and out at sea I can empty the holding tank using the macerator. Anyway I used teflon tape on all the fittings with no leaks and no damage, again the teflon is soft and pliable and since teflon is inert (non-reactive) it will not cause any problem with the plastic on the tank that I know of. dave
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John K Kudera
since you have it out
I think this is a perfect time to add an inspection port on top of the tank, in an area that can be accessed when back in place in the boat. I would also reccommend that you consider thru hull fittings to replace the broken or damaged one using the inspection port. as access to the inside of the tank. I haven't done it bou will when I need to. John
I think this is a perfect time to add an inspection port on top of the tank, in an area that can be accessed when back in place in the boat. I would also reccommend that you consider thru hull fittings to replace the broken or damaged one using the inspection port. as access to the inside of the tank. I haven't done it bou will when I need to. John
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Peggie Hall/Head Mistress
Now you know why nothing but...
teflon tape should ever be used to seal tank fittings. I'm not sure from your description what's cracked--the male PVC thread-to-barb fitting? Or the female threaded fitting it screws into? If it's male PVC fitting, a larger vent fitting will be easy to do yourself ...but if it's the female fitting, it's gonna be bit trickier, 'cuz the female fitting is polyethylene--same material as the tank--and nothing bonds to it permanently. In that case, I recommend you take it to a local plastics fabricator who can knock it out and spinweld a larger fitting into the tank. He'll prob'ly charge you all of about $10 to do it. And before you start installing any fittings or hoses, I recommend you read the article on replacing hoses in the Head Mistress forum library. It's especially important that fittings not be overtightened. If it's the female fitting in your your tank that's cracked, overtightening is the reason it cracked. Tank fittings are NPT standard, which is slightly--so slightly that it's not visually apparent--tapered. Fittings should only be tightened just one turn past hand-tight, plus just enough to aim an elbow where it needs to go--even if threads are still showing. Any more than that puts stress on the female "collar" that's guaranteed to crack it. And it doesn't usually happen immediately...6 months later a little change in temperature creates just enough expansion, and "pop"....then you're back asking how to fix the crack in your tank.
teflon tape should ever be used to seal tank fittings. I'm not sure from your description what's cracked--the male PVC thread-to-barb fitting? Or the female threaded fitting it screws into? If it's male PVC fitting, a larger vent fitting will be easy to do yourself ...but if it's the female fitting, it's gonna be bit trickier, 'cuz the female fitting is polyethylene--same material as the tank--and nothing bonds to it permanently. In that case, I recommend you take it to a local plastics fabricator who can knock it out and spinweld a larger fitting into the tank. He'll prob'ly charge you all of about $10 to do it. And before you start installing any fittings or hoses, I recommend you read the article on replacing hoses in the Head Mistress forum library. It's especially important that fittings not be overtightened. If it's the female fitting in your your tank that's cracked, overtightening is the reason it cracked. Tank fittings are NPT standard, which is slightly--so slightly that it's not visually apparent--tapered. Fittings should only be tightened just one turn past hand-tight, plus just enough to aim an elbow where it needs to go--even if threads are still showing. Any more than that puts stress on the female "collar" that's guaranteed to crack it. And it doesn't usually happen immediately...6 months later a little change in temperature creates just enough expansion, and "pop"....then you're back asking how to fix the crack in your tank.
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Claude L.-Auger
Crack is in female fitting.
Thanks to all. As mentioned above, crack is in the thread area of the female vent fitting. I found this when I remove the tank to be able to remove sole and clean bilge area. The hose popped out when I touched it ! Which is probably why previous owner had caulked it ! And had also caulked the 1½" elbow fitting rather than use teflon. I will try to locate a plastic fabricator as per Peggy's suggestion. BTW, I had already read the post on replacing hoses. Great info. And I have been trying to find +/- 6' of Sealand hose. If I can't locate 6', I'll probably resort to using sanitation hoses as offered by boatyards around here.
Thanks to all. As mentioned above, crack is in the thread area of the female vent fitting. I found this when I remove the tank to be able to remove sole and clean bilge area. The hose popped out when I touched it ! Which is probably why previous owner had caulked it ! And had also caulked the 1½" elbow fitting rather than use teflon. I will try to locate a plastic fabricator as per Peggy's suggestion. BTW, I had already read the post on replacing hoses. Great info. And I have been trying to find +/- 6' of Sealand hose. If I can't locate 6', I'll probably resort to using sanitation hoses as offered by boatyards around here.
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