Interestingly, I just this morning got a newsletter from SeaLake Yachts in Texas
and it has this excellent article on cleaning marine
MARINE TOILET MAINTENANCE:
Cleaning The Lines
Heads flushed with salt water
accumulate scale deposits in the discharge channels and hoses. Scale deposits cause a head
to get progressively harder to flush and it is scale on the valves that allows water
in the discharge line to leak back into the bowl. Calcium deposits eventually lead to total blockage, a most unpleasant prospect.
Avoiding this problem is as easy as running a pint of white vinegar through the head
once a month. Move the vinegar through the head slowly, giving the head a single
pump every 4 or 5 minutes. The mildly acidic vinegar dissolves fresh scale inside the head and hoses. When the vinegar has passed all the way through the system, pump a gallon of fresh water
through to flush the lines.
If you suspect you already have a scale build-up, dissolve it with a 10% solution of muriatic acid, available from most hardware
stores. The acid won't harm porcelain, plastic, or rubber parts
. It does attack metal, but consequential damage takes a long time. The biggest danger
is to eyes and skin, so be sure you observe all label precautions.
Pour two cups of acid into the bowl. It will fizz as it reacts with the calcium deposits on the bowl valve. When the fizzing stops, pump the head-intake closed, just enough to empty the bowl. This moves the acid into the pump.
After a few minutes, pump again to move the acid into the discharge hose. Let it sit a few more minutes before opening the intake and thoroughly flushing
the toilet and lines. The acid is "used up" as it reacts with the calcium, so heavy scaling may call for more than one treatment. Scale and salt
also finds their way into the anti-siphon valve in the discharge line.
Remove the valve and soak it in warm, soapy water to dissolve deposits that could be holding it shut-or open.
To keep the pump operating smoothly, follow your monthly vinegar flush with a dose of oil
. The best choice is a lubricant intended for marine
toilets, but you can also use mineral oil
or vegetable oil. Oil lubricates the pump wall and helps to keep internal rubber and leather parts
supple. The usual treatment is to let a little water into the bowl, pour in a couple of ounces of lube, and pump this through the toilet. This method is adequate, but less than ideal because it lubricates only the discharge side of the pump.
To also lubricate the intake side, disconnect the intake hose from the closed seacock and pour the oil into this hose. Pumping the head will pull this oil through both chambers of the pump.
While you are servicing the head, lightly coat the piston rod with Teflon grease. This will prolong the life of the piston-rod seal.
Marine toilets need not stink, but they often do. The discharge hose is, by far, the most common culprit. To check yours, rub the hose with a clean cloth, then sniff the cloth. If it has picked up an odor
, the hose is permeable and you will never eliminate the odor
until you replace this hose with a proper sanitation hose.
Leaking connections are another source of odor, and you can use your cloth the same way to locate a leak. Also check the seal around the piston rod. On some heads, tightening the seal will stop a leak; on others a leaky piston-rod seal must be replaced.
Another common source of head odor is grass and other marine life trapped inside the flush-water passage
under the rim of the bowl. Prevent this by installing a strainer in the intake line.
An anti-siphon valve in the discharge line can also release odors into the boat. A properly installed valve vents outside the cabin
Seems fair to include a link to their site so you can subscribe to their very useful newletter if you want. I'm not involved with them in any way other than receiving their ezine so I hope this is OK:
Sea Lake Yacht Sales Home Page