First, you have my sympathy. I've been there, on someone else's boat, and it was awful. Second, It is do-able, you just have to be brave and fearless.
Anything short of complete removal
is going to bite you someday, only prolonging the number of times this issue will hurt. So, you have to remove the tank and replace it the way it should have been built in the first place. The key word here is removeable. Murphy's Law has not been, nor ever will be eliminated from the other Laws of Nature.
It's only a pain, it's not about total destruction and perpetual chaos. Remove everything on top of the tank, and, if necessary, any vertical elements. If you do it somewhat neatly, you will be able to cover the damage with trim and no one but you will have any idea of what happened. Then, wash the interior
of the tank with detergent, bleach and lots of rinsings. It's still going to be nasty, but it will not be as bad as it could be. Then, chop off the elbow
and haul out
the tank. Now, let the compartment dry out so you can examine every part of the empty space for rot
or other issues. Fix those. Now that the hose is clear, this is the best time to install another one, so do what needs to be done to track the line to its deck
fitting and to the macerator pump and overboard
discharge. Make sure the macerator pump is functioning perfectly and is accessible for future replacement. These pumps often sit idle for so long that the uric acid crystals and other waste seize up the impeller like concrete. You should "exercise" the pump monthly, even for a couple seconds. Consider replacing the pump now while you are overhauling everything. It will never be cleaner than it is at this point. It's only money
, and life should be more than repairing sewage systems.
Next step, a new tank. This time you get to learn from the mistakes
of others. The simplest and cheapest solution is to make the tank yourself out of plywood
, sealed in epoxy
resin, with standard fittings for through hulls. Make the tank slightly smaller at the end where the input and exhaust
hoses, and the vent hose, are attached. If you don't have the three hoses at the same end, try to make it happen at this stage. Since you can make the tank any size or shape needed, do so, because there will never be a better time. Most folks never get a chance to make their boats (or sometimes, their lives) better, like this. You should consider this awful endeavor as a blessing in disguise. Future owners of your boat will never know what a great person you are.
Make sure that the top of the compartment is completely removable and quick to open for inspection
. You can even build in a cleanout port if you are really insane. I am, and I did.
Lastly, this will be the only time you can make the decision to go with an aerobic digester holding tank
. It requires TWO vent hoses, each 1 1/2' in diameter, located at the top of each end of the tank, which then lead to through hulls on each side of the hull
. They capture the breeze and exhaust
the gases out of the holding tank, allowing you to charge the system with aerobic bacteria which consume the poop and don't smell anywhere as bad as what most folks have right now. It's a fair amount of work, and it's not for every boat, but it should be considered, at least.
If you can relocate the tank to a position above the waterline, that's even better because it allows you to have a self-draining tank without the need for a macerator pump. Here's a picture of my system.
Good luck! The reason I can be so smug is that I built my own boat from scratch, while working on building boats for others. I learned what problems they had, and built so that I could avoid the same problems. So, EVERYTHING in my boat is removable, and has inspection ports
or access so that I can put an eyeball and a hand, with the necessary tool room to swing it. I make money
working on other people's boats, not my own.