Leaking waste tank on 2005 Hunter 33

[4Winds]

Waste tank (not sure how large it is) on 2005 Hunter 33 acquired 2 years ago (I think I am the 5th owner) seems to have a leak pooling on the top of the tank , running over the side into bilge. Survey at purchase rated it is good condition, though I always questioned that as tank was visibly bulged and there was residue from an older leak, signs of maintenance work. [See tank from Side; looks nearly same as before but of course wet now from use] These leaks seemed to be old however and nothing was noted until rather recently as temperatures started to exceed 80oF. Recent photography reveals hose (which i think is coming from the head) no longer firmly anchored to the tank [See tank from above, connection is not tight ... cannot remember if it looked that way before i think it did ...]. Tank has only been emptied 2 times since purchase. No one poops in the head, just urine, and only in last 6-9 mos or so. Issue discovered as temperatures started to rise and smell of old urine began wafting from tank compartment into rear stateroom through to salon. Cannot tell if vent on outside works, though probably it does is as a stream of dirty liquid drips out of it after head is used [see ExteriorVent] . I do not think it is blocked. Solenoid also does not work, has never worked since I have had it. Given the bulge and the loose hose (how much pressure could have caused that and how likely can a good seal be gotten from cleaning and tightening? Wondering whether this rates another repair or probably a complete overhaul, and if it can be done in the wetslip (Which I think it could be). Looking for recommendations on approach, source of parts .... How difficult is the replacement?

 

[Peggie Hall HeadMistress]

I'm betting your tank vent is blocked.
Holding tank vents 101.
All tank vents have two main functions: to provide an escape for air displaced by incoming contents and provide a source of air to replace contents as they're pulled out. When air displaced by incoming waste cannot escape out the vent the tank becomes pressurized, creating increasing back pressure that prevents the toilet from flushing.

Without a source of air to replace contents as they're being sucked out of the tank, the pumpout will pull a vacuum that'll prevent it from pulling out more than a gallon or two. A particularly strong pumpout can even implode a tank... That the tank is leaking on top is a strong indication of two things: that the tank is over-full and that there's a crack in the top of the tank 'cuz fittings on tanks in Hunters are almost always installed in one end of their holding tanks.

Do NOT use the toilet again or try to pump out or dump the tank until you've cleared the vent. Without a source of air to replace contents as they're being sucked out of the tank, the pump will pull a vacuum that'll prevent it from pulling out more than a gallon or two. A particularly strong pumpout can even implode a tank.

The two most common locations for a vent blockage are the vent thru-hull and the other end of the vent line--that end of the hose and the vent fitting on the tank. Start by cleaning out the thru-hull...use a screwdriver blade, ice pick--whatever works. If that doesn't result in a spew out the vent, you'll need to relieve the pressure before removing the vent line from the tank to clean them out...so open the deck pumpout fitting VERY CAREFULLY with a hose at the ready. Be sure you're UPwind of it! Scrape out that end of the vent line and the vent fitting on the tank...reconnect the vent line.
Once you've cleared the vent, you can pump out the tank, which I strongly suspect hasn't actually happened since you bought the boat if the vent has been blocked that long..meanwhile you've continued to flush into It.

If, as I suspect, there is a crack in the top of the tank or anywhere else in it, it's not repairable...you need a new tank... Duraweld in FL was most likely the supplier to Hunter. Looking at your photos, ALL the hoses should be replaced too.

I'm gonna suggest one more thing: that you get a copy of my book (see link in my signature). Its title (my publisher's idea) is a bit misleading...'cuz although it does deal with every source of odor on a boat and how to cure, or better yet PREVENT 'em, it's actually a comprehensive "marine toilets and sanitation systems 101" manual that explains the laws, describes all the types of systems and how they work, and will help you learn how to operate and maintain your system to prevent 99% of problems instead of having to cure 'em. 'Cuz you get to do any preventive maintenance on your terms when it's convenient...the need to cure a problem never happens when it is!

Meanwhile, I'm always glad to answer questions a solve problems.

--Peggie

 

[4Winds]

Peggie, fully on board with your advice. I'm so glad you are part of this forum. Book ordered just now. Can you provide me your direct telephone # and convenient time to call? Any time works for me ... I am in Wilmington, NC. I'd really like to run a number of questions by you, the first being how to pay you for the time I am going to need. My private email is 7yards@protonmail.com. THANK YOU.

 

[Peggie Hall HeadMistress]

I'll be glad to provide you with my phone number and email address. However for safety's sake I'll do that via PM.

--Peggie