During our circumnavigation (day 10, specifically), we found that our macerator pump didn't work. We were three miles off shore and noticed that the tank-minder light was one, indicating a full holding tank. The pump, however, wouldn't spin. Broken? Packed solid with poo?
This was the start of a series of unfortunate incidents that lead to us going hard aground on a falling tide in Ocean City Maryland. A digression best left untold.
I think our holding tank has a volume of about 40 gallons. Our heads don't take much water, but at a gallon per flush, that means each of us gets 20 trips to the head. Not to get too scatological, but we can assume this leaves us about four days between pump-outs.
The macerator pumps the holding tank contents overboard. It's certainly rude (and illegal) to pump poo directly into confined, in-shore waters. Three miles off-shore, however, it's acceptable to pump poo overboard. We tried. And failed.
My "To Do" item was simply "fix macerator pump". I downloaded the owner's manual for the Jabsco 18590-2092. This is an electric pump with two front-ends screwed onto it. A macerator with a cast bronze cutter and a nitrile impeller. The owner's manual says that "The motor shaft has a screw driver slot machined at the rear of the motor." This is hard to verify because the whole unit is mounted in an awkward location under the cabin sole. That would be better than taking it apart. Right? Who wants to get covered in poo?
It turns out that we had a random box (in the random "came with the boat" box collection) that included a rebuild kit.
It had all the poo-pump parts one could ever want: gaskets, a wearplate, a replacement chopper plate, a new impeller, new housings. We even had a mysterious little doo-dad that is called a "slinger".
But. Who wants poo-pump parts? If you have the parts it means you have to take the pump apart to rebuild it. And it's full of poo.
Bad, But Not Too
Here's the secret for rebuilding the poo-pump. Lots of paper towels.
It's going to drip. And that means it's going to drip into the bilge, where you'll smell it forever.
Wedge small plastic buckets everywhere. Paint buckets. Yogurt tubs. Anything that can be jammed under the pump and plumbing. For us, there's a big spot under the elbow where we use an old plastic paint-mixing bucket. I have some old Cool-Whip tubs that I use for catching oil in the engine room, those can be wedged near the output.
Have a spare bucket ready for tools and paper towels. There will be a lot of paper towels. And dirty tools that you'll want to wash.
Take off the hose clamps. Work the hoses off the fittings. This isn't going to be easy since the hoses will be solidly frozen in place. I'm going to measure them for next time and buy replacement of the proper sizes so I can cut the old hoses off instead of trying to preserve them. Much quicker.
Jam paper towel wads in every opening. Not immediately. Wait until after the initial splurge of poo drops out. Catch this in a bucket. Avoid gagging. Then jam a wad of paper in.
Once you have things stabilized—i.e., not dripping—you can then break the pump down to rebuild it. BTW, this is why gloves don't work out well. Small acorn screws and lots of twisting and yanking will mostly tear up rubber gloves. If the gloves are tough enough, you can't feel what you're doing.
Sometimes, you just have to get dirty.
I didn't do the full rebuild. Two reasons. First, the rebuild housing doesn't have the same hose fittings on the original hosing. I would need an extra bit of plumbing to use the new housings. Second, I couldn't (easily) get the pump section off the motor. The macerator slipped right off. I didn't want to force the pump housing.
Inexplicably, the cast bronze chopper had somehow fallen off the drive shaft. As if the motor had been rotating backwards and unscrewed it. Or something.
So I screwed a new chopper plate on, rotated the drive shaft manually a few times. I hit the switch on the breaker panel and it spun. Okay. It "works". Without a full "system test", however, it's difficult to call this job Done.
Rather than pursue a full rebuild (i.e., replace the impeller, wear plate, gaskets, and the "slinger"),I reassembled the pump without using any other parts from the rebuild kit.
Next time we're three miles off shore, we'll test it to see if it really works. If not...well...I'll try again.
The owner's manual had this glib assurance: "The motor shaft has a screw driver slot machined at the rear of the motor." I got down there with mirror and flashlight and could neither confirm nor deny the presence of this screw driver slot. I'm hoping I just overlooked it somehow. That would be much nicer than taking it all apart.
Of course, I can't wash the poo in any of the galley or head sinks on the boat. I have to carry the buckets, towels, tools, etc., into the shore-side head to pour it into the toilet. And then add rinse water from the most accessible shower and pour into toilet. This is a lot of careful walking around to avoid slopping anything onto the floor. It takes several rinses to get it clean enough to turn a hose on it outdoors.
We have a spray bottle of Simple Green concentrate. I used this (undiluted) to wipe down the drip areas. I used a bunch more to clean the buckets after they were hosed out. I used even more Simple Green to clean the tools in the buckets (cleaning the buckets a second time). I then used some diluted to wash down the area under the pump. Then I rinsed the area under the pump with a quart of vinegar diluted with a quart of water.
Hopefully, it will smell pickle fresh when we get back.