Cant dump our blackwater

[nauticat]

Hi we have a Seawind 1250 and over the years had a few problems with calcifying in the pipes from the toilets to the the black water tanks. Our latest problem, we cant dump the black water in our starboard tank. Has any one had similar problems and also what is the best preventative action so it doesnt happen again. thanks.

[Factor]

Put a hose up the discharge from the bottom and turn the pressure on - it should help to clear a blockage, pull it out and see what happens, try again a few times if need be.

In future try half filling the tank by putting fresh water in the tank from the deck fill, go sailing and dump. Also when leaving the boat fill the bowl with fresh water and empty out, your shower hose should reach easily. When you slip the boat for antifoul etc, take all accessible pipes off and clean them.

[roverhi]

The head on my new to me boat had a very restricted flush line. Could pump but a lot of backpressure getting worse. Went to Costco and bought two gallons of white vinegar. Poured about a quarter gallon of it in the head and pumped. Let it sit overnight and poured another 1/4 gallon in and pumped it out of the bowl. Pumping out the 2nd load of vinegar was easy. The next day poured another 1/4 gallon of vinegar through and back pressure was all but gone. Did a fourth apllication and all has been fine ever since though have used the head little. When I say pump the vinegar through, I mean empty the bowl but don't keep pumping. Maybe a little fresh water to get the vinegar farther into the hose but don't completely flush out the line.

Urine creates a buildup of calcium like substance in conjunction with salt water in the exhaust line that eventually blocks the line kind of like crud in our veins as we get more experienced. The acid in vinegar breaks down the calcium and will eventually clean out the lines. A more potent acid might work faster but that stuff scares me if I was to spill it or it somehow leaked out. Before I discovered the vinegar solution, would remove the exhaust line and beat it against a rock or tree to break up the deposits. That was a total nightmare mostly with getting the hose off the head, holding tank, and thru hull fittings.

[contrail]

Originally Posted by roverhi

The head on my new to me boat had a very restricted flush line. Could pump but a lot of backpressure getting worse. Went to Costco and bought two gallons of white vinegar. Poured about a quarter gallon of it in the head and pumped. Let it sit overnight and poured another 1/4 gallon in and pumped it out of the bowl. Pumping out the 2nd load of vinegar was easy. The next day poured another 1/4 gallon of vinegar through and back pressure was all but gone. Did a fourth apllication and all has been fine ever since though have used the head little. When I say pump the vinegar through, I mean empty the bowl but don't keep pumping. Maybe a little fresh water to get the vinegar farther into the hose but don't completely flush out the line.

Urine creates a buildup of calcium like substance in conjunction with salt water in the exhaust line that eventually blocks the line kind of like crud in our veins as we get more experienced. The acid in vinegar breaks down the calcium and will eventually clean out the lines. A more potent acid might work faster but that stuff scares me if I was to spill it or it somehow leaked out. Before I discovered the vinegar solution, would remove the exhaust line and beat it against a rock or tree to break up the deposits. That was a total nightmare mostly with getting the hose off the head, holding tank, and thru hull fittings.

PUMP IT OUT ALL THE WAY!!! Some rubbers react with the vinegar and increase their size immensely. I advised some friends to do just as you did, on the Jabsco manual heads. They were leaving the boat for a couple of months and it seemed that leaving a solution of vinegar and water was a great idea. But, when they got back, they couldn't pump the heads at all. We opened them up and the valves had gotten so big they couldn't be moved at all, or be put back in. I have known this to happen with other toilets so beware! Too much of a good thing can be exactly that.

[nauticat]

Originally Posted by Factor

Put a hose up the discharge from the bottom and turn the pressure on - it should help to clear a blockage, pull it out and see what happens, try again a few times if need be.

In future try half filling the tank by putting fresh water in the tank from the deck fill, go sailing and dump. Also when leaving the boat fill the bowl with fresh water and empty out, your shower hose should reach easily. When you slip the boat for antifoul etc, take all accessible pipes off and clean them.

Cheers for the tip

[ranger58sb]

Originally Posted by nauticat

Hi we have a Seawind 1250 and over the years had a few problems with calcifying in the pipes from the toilets to the the black water tanks. Our latest problem, we cant dump the black water in our starboard tank. Has any one had similar problems and also what is the best preventative action so it doesnt happen again. thanks.

We cleared a uric scale blockage from bowl to tank last year using a purpose-made product called Sew Clean. (Raritan's CH -- Cleans Hoses -- is the same stuff.) One treatment, fixed.

Can't speak to why you can't empty your holding tank, although you might check to be sure the vent isn't blocked.

-Chris

[Factor]

Originally Posted by nauticat

Cheers for the tip

I forgot to mention make sure the y valve is set to discharge so the water goes up, I have fixed a few Seawind blockages this way

[holtjp]

One of the many reasons I converted to a composting head!

[Parallel Life]

There will be a thick layer of calcified plates on the bottom of the tank that is blocking the outflow. It's like cement, a strong stick won't even break it with a good prod. White Vinegar is good but for serious calcification use a solution of HydroChloric acid, available from marine shops. This dissolves it away. Leave the outflow valve open and unless you're on the hard it will be gone 24 hours later/

[flyingfin]

Another vote for vinegar! But dont leave it in there long. Fill with 2 gallons vinegar and 2 gallons water. Go out on rough day so the solution sloshes around in your tank. Then dump in a bag of ice, continue to slosh around for another 15 to 30 minutes, then dump tank. Then refill with 3 to 4 gallons of distilled (or pure rain) water.

[hellosailor]

"Urine creates a buildup of calcium like substance"
Yes. A long time ago I was taught that if you're going to use the head, PUMP IT TEN STROKES or don't bother pumping it at all. The ten strokes (and your own number may vary) is to ensure that you've TOTALLY pumped any sewage through the hoses and cleared them of everything but seawater.
The blackwater discharge line may be more problematic, but between using vinegar or other acid to clean it, and then flushing more seawater through more frequently in order to keep it clean, that should be possible too.
If it is really clogged hard and solid...it may be time to replace the line. They aren't meant to last forever.

[jacktheflyer]

Originally Posted by Parallel Life

There will be a thick layer of calcified plates on the bottom of the tank that is blocking the outflow. It's like cement, a strong stick won't even break it with a good prod. White Vinegar is good but for serious calcification use a solution of HydroChloric acid, available from marine shops. This dissolves it away. Leave the outflow valve open and unless you're on the hard it will be gone 24 hours later/

I had this and the calcification broke up clogging the outlet. Temporary fix was to backflush it from the discharge. Vinegar didn't touch it and even stronger acids did not resolve it. Ended up removing the tank and cleaning manually. Now use an enzyme treatment which is supposed to break up the uric acid crystals and decompose the sludge. Can't vouch for it yet.

[yeloya]

Black water tanks and all of the lines have to be washed with acidic solutions periodically, at least once a year to avoid any deposit. We do that for all of our boats and never had any problem. If you wait until the lines are half blocked, you will ahve to use more or stronger acids whic may cause other problems.
Well, when the charter customers put one meter of toilet paper on the bowl, that's a different matter. Then you have to use pressurised water as one forumer said. Otherwise, Calcium deposit cannot be cleaned by pressure alone.


Cheers


Yeloya

[mark_morwood]

We experienced that same problem and it was the calcified deposits breaking off the tank and clogging the outlet, in our case a 2" gravity fed dump line. We could clear the line be sending a hose back up the hose from in the water (not every pleasant when it suddenly let go). I eventually got our tanks clean by spraying the interior with high pressure water from the washdown pump through an access fitting in the top of the tank. This broke up all the deposits into small enough pieces that they could be washed out.

[Dave_S]

Originally Posted by roverhi

Urine creates a buildup of calcium like substance in conjunction with salt water in the exhaust line that eventually blocks the line

Owwwwwwwwww sounds like you've got a kidney stone