Clog in sanitation outlet

[SEMPERAVANTI41]

On my new to me Bavaria C57, the holding tanks are located in a cabinet above the head. They are suppose to drain by gravity when the thru hull valve is opened. Unlike my previous Hunter 50, there is no macerator pump. Anyone have a suggestion as to how to clear a clog preventing the tank from draining? Have tried pumping out the tank and filling with fresh water 3 times, no luck. Hope to not have to resort to mechanical means. Thinking of plugging up the air vent and pressurizing the deck pump out fitting.

 

[dlochner]

You might try Sew Clean.

Sew Clean | Descalers | Drew Marine Trac Ecological

Sew Clean® is the best and most proven method of removing any clogs, oders, and build up of uric scale in black water systems.

www.trac-online.com

 

[kloudie1]

A diver with a fish tape could probably get it out from under the boat
Wouldn't pressurize it unless you relish a poop volcano..

 

[Ralph Johnstone]

Thinking of plugging up the air vent and pressurizing the deck pump out fitting.

Don't even dream about pressurizing the holding tank in the hopes of pushing the obstruction out of the tank.

Assume for a minute the side walls of your tank were 24" X 24" and you added air at only 1 PSI. There are (24 X 24) = 576 square inches each with a force of 1 pound acting on it. You now have 576 lbs. acting on that one wall.

I can see the shi _ _t show now. And you don't want a bucket of popcorn on your lap at ringside for this performance .

As @dlochner has suggested, I would try chemically cleaning it out with Sew Clean or some other chemical treatment if the first one doesn't work. Adding heat up to about 100 deg. F. MAX. may also help.

 

[SEMPERAVANTI41]

I have forgotten about using pressure!

 

[Captain Larry-DH]

I the same situation with similar gravity discharge through a 2” hose. The problem was caused because the direct to sea discharge was not used enough. Prevention might be aided by regular use of descaling chemicals, and by using Zaal NoFlex Digester.
In August I went to a pumpout station and then immediately filled the holding with fresh water. Then I dived with snorkel and mask and plunger. It worked! A little Then it was totally clogged again.
The ultimate fix was to replace the hose. Not a pleasant or easy task. Here’s a tip: Use a multitool saw to cut the old wire reinforced hose ends where they fit the barbs, being careful not to go all the way through to the barbs.

 

[dlochner]

Use a multitool saw to cut the old wire reinforced hose ends where they fit the barbs, being careful not to go all the way through to the barbs.

Get a carbide blade for the oscillating tool, they're expensive but they last much longer.

 

[Captain Larry-DH]

Get a carbide blade for the oscillating tool, they're expensive but they last much longer.

A better tool for this job is your checkbook

 

[Roland5048]

A better tool for this job is your checkbook

Sometimes the cheapest tool.

 

[Terry Cox]

Anyone have a suggestion as to how to clear a clog preventing the tank from draining?

Different model boat and situation, but started a clogged sanitation hose thread awhile ago that garnered considerable interest. Worth a read to learn what did and did not work in my situation. Please let us know your outcome. That thread is here: Clogged Sanitation Hose

 

[Peggie Hall HeadMistress]

Muriatic acid--available from any hardware store--will work and costs a lot less than SewClean.

However, prevention is always a lot cheaper and easier than cure:
A cupful of distilled white vinegar flushed all the way through to the tank once a week will prevent sea water mineral buildup in the toilet drain line, but won't do a thing for the holding tank drain.

To prevent that, do this 2-3 x a season: Pumpout the tank, then put 4-6" of clean FRESH water into the tank via the deck pumpout fitting 'cuz that sends the water into the tank at the bottom to stir up any sludge so it can be pumped out. Repeat, repeat, until you're pumping out clean water. Then do it again with the discharge thru-hull closed so that the water will run into the direct discharge line, this time using something like NoFlex...it'll take a little time to work. If you haven't been doing this as PREVENTIVE maintenence, it'll be a bit of a PITA to do the first time and may require a healthy dose of muriatic acid, maybe more than once, that should be allowed to sit for 45-60 minutes before flushing out with plenty of clean fresh water. Follow al safe handling instructions for the muriatic acid.

Always rinse out the tank and drain line after every use. open the drain seacock to make sure it gets completely rinsed out after every pumpout and tank rinse.

--Peggie

 

[rgranger]

Might a drain snake/router used from underneath work? These are only $20 at lowes