De-Scaling Waste Lines

[Intentional Drifter]

Been there -- tried all that. The muriatic acid will take out the scale, but depending on your hose, you could also damage it if you leave it in too long. Also, it won't get the stink out of the hose, which permeates all the way into the hose.

Regular vinegar treatment works well to keep the deposits from forming in the first place, but won't touch it once there.

Easier to just replace the hose. While it costs more, using a better quality hose will help keep the stink down, longer. The "Green Stripe" stuff is a better quality while not outrageously priced.

Just another one of the joys of boat ownership. Hopefully, your hoses are run such that you can get to them easily.

ID

[ishipaco]

We too encountered the common problem of the buildup of deposits in the head discharge line. Despite trying all of the already mentioned "tricks" to solve the problem, we found that they were only partially effective. We still had to remove the discharge hose about once a year and "pound" it to dislodge the accumulated deposits. This is typically a difficult and messy project. I'd much rather spend the time sipping rum in the shade.

After about eight years of using the above-mentioned old "tried and true" techniques, we finally discovered the only way to avoid the problem, and it's deceptively simple. Here it is:

FLUSH YOUR HEAD MORE! The problem is caused by residual waste matter, especially urine, which remains in the hose after inadequate flushing. Urea and other dissolved matter tends to precipitate out and become deposited on the hose walls. Very few cruisers actually flush their heads enough. I guess the reason for this is something like "out of sight, out of mind."

We put a few pieces of toilet tissue in the bowl and then began flushing it, while watching at the thruhull location to determine when the tissue paper was expelled. We counted the strokes required for this. Then we added about 50% more strokes for good measure. This solved the problem for good, and we went for the last five years without having any problem with deposit buildup in our discharge hose.

This technique worked for our manual head with a direct discharge to the sea. I don't know how well it would work with some of the more modern, complicated heads. Also, if you are having to discharge into a holding tank, this technique will rapidly fill your holding tank, requiring much more frequent trips to a pump-out station.

On the other hand, if your situation is like ours was, where we were usually anchored off in foreign countries, where direct discharge is practical, the technique works well. I'll leave it up to you: either flush little and expect to be cleaning out your discharge hose more often than you'd like, or flush a lot and never have to worry about the problem again!

[rebel heart]

Yeah, a lot of it is the urine not so much the sea water. If it was just sea water, your galley outlet would clock at the same frequency as the head. You need to pump it more to clear it all out, which of course causes the holding tank to fill up more.

We're at about 3 years between removal / replacement of hoses. It's not really that hard once you get the hang of it. I don't bother trying to re-use hoses. I keep a bunch of spare onboard, and fashion new pieces. That way when removing I can just saw the old ones off their fittings and speed up that part of the job.

I push vinegar through as well. If you leave vinegar in your lines for a few hours and then discharge overboard, you'll be amazed at all the gunk and goo the vinegar has managed to discharge.

We keep a spray bottle of white vinegar in the head. Some spritzes in the bowl is always welcome.

[boden36]

We had a hotel for years, and the gunk that used to build up in the latrine drain was almost like limestone. We used to pour dilute hydrochloric acid as used by brick cleaners down the drain and let it sit. Used it straight out of the bottle. You can buy it at any hardware store. Worked well and took the smell away too but the fumes are pretty fierce.
Regards, Richard.

[GordMay]

Originally Posted by boden36

... We used to pour dilute hydrochloric acid as used by brick cleaners down the drain and let it sit. Used it straight out of the bottle...
... but the fumes are pretty fierce.
Regards, Richard.

Be careful.
Hydrochloric acid (± 31.45% HCl) is often sold as “Muriatic” acid.
Chlorine gas is produced when mixing hydrochloric acid with common oxidizing chemicals, such as sodium hypochlorite (bleach, NaClO) or potassium permanganate (KMnO4).

[Rex Delay]

Thanks to all for your insights. I am going to replace the hose.

[Pete7]

Originally Posted by Rex Delay

Thanks to all for your insights. I am going to replace the hose.

Good plan. We did ours last year when it blocked half way through our holiday

The new hose was $50 for 5m, it just wasn't worth faffing around with the old stuff which had 1.4" of scale inside. We did the jabsco pump at the same time, huge difference to the old pump.

Pete

[rover88]

It cost me about $80 annually to replace my head's hoses. I figure it would cost more to be constantly pouring chemicals down the toilet (figuratively and literally). As far as I am concerned this is money well spent to keep the Skipper from complaining of the odor and me from having handle nasty poo-poo hoses more than once a year.

[Mark Zarley]

THE OLD ADAGE USE IT OR LOSE IT APPLIES HERE. BEING ABOARD YEAR ROUND AND CONDUCTING ALL OUR "BUSINESS" ON THE BOAT KEEPS THINGS "MOVING". ONLY REPLACED THE HOSE ONCE IN 11 YRS. THAT SAID IT IS STARTING TO "FLUSH" A LITTLE SLOWER.

[osirissail]

Human urine plus sea water makes the scale that is as hard as fired enamel. There is little you can do to remove it non-violently. You can slow it down with vinegar. You do not get the build up if you use fresh water to flush but that requires a rather large potable water storage/replenishment system.
- - The scale buildup is just one of many "prices" we pay for living on the water. Normally it takes years for the stuff to seal off a hose and then you merely remove the old hose and put in a new piece so make sure you can access the area where the hose is located.