Head & shower

Emptying the holding tank

I wanted to pump out the holding tank from the start. It held about 5 gallons of something, and I expected really smelly gray water with poop in it, so I kept putting it off. But curiosity won. Not about what was in the tank, of course. I wanted to see what's under the compression post and how the mast is grounded for lightning. From the Irwin owners group I knew that the tank gives access to the area under the mast and to the shower drain.

The plan anyway was new gray water hoses, an electric toilet, and a Y-valve to go overboard offshore.

But you can't get a tank dry with a normal pump-out. The hose is 1-1/4 inch, and an inch of stuff always stays at the bottom. And the marina had no pump-out back then. I'd have to motor somewhere, pay, and still deal with the gallons left inside.

So I did it myself, with a 5-gallon Home Depot bucket with a lid, a piece of vacuum hose and the shop vac. Two holes in the lid: the vacuum on one, the hose on the other, and suck the stuff into the bucket. The vacuum stays clean, the bucket I can carry and dump into the sewer properly, and the tank ends up completely dry. A good surprise: it didn't smell too bad, thanks to the deodorant the previous owner had put in.

I took out the broken manual toilet and the gray water hoses (4'6" and 5'10", noted here in case I ever put them back and forget). For the next couple of years: a porta-potty. The only problem was the toilet bolts sticking up from the floor, which I didn't want to remove. So I made a temporary mount that uses those bolts. The problem came with its own solution.

Then I cleaned and repainted the area under the head cabinet and the toilet base. Pretty, isn't it?

In February 2023 I made a proper plywood plate for the porta-potty, with holders so it can't run around the head in a seaway, and cut off the extra sanitary hose.

Making a real shower pan

Here's one more thing built to fail. By design, the head walls stand with their plywood edges sitting in the shower pan. That means the main bulkhead and the head walls will rot if you use the shower a lot. To avoid it, you'd have to shower without a single drop on the walls and never leave any water on the floor. Possible? Of course not. So you get a nice smell and rotten plywood.

So I decided to glass all the walls to the shower pan and paint them with Interlux two-part topside paint. Good practice before I paint the topsides and the deck, too.

Step 0: dig out the rotten wood. The whole bottom of the port main bulkhead was rotten to trash. My plan was four 5/16 bolts to hold the bulkhead to the liner, cut out the trash, then teak blocks and a couple of plates to carry the bulkhead load to the floor. But the floor isn't structural, so maybe it's better to let the bulkhead hang from the liner.

Step 1: sand the joint area on the walls through the melamine down to the plywood, and through the gelcoat on the liner, so the glass bonds well.

Step 2: fill the big gaps with polyethylene foam, just to hold the fillets. Not structural.

Step 3: make a nice (or pretending to be nice) thickened epoxy fillet.

Step 4: one layer of glass cloth over it, so it doesn't crack later.

Then filler, sanding, primer and paint over the next days.

Remember the crack in the floor next to the compression post? With the rotten bulkhead out, I could finally reach both sides. I ground it out about 4 inches back to rebuild the floor rib. Interesting: right at the crack the fiberglass changes color. It looks like the part under the post has no glass, or a different resin. Then I built it back up.

In mid-January the left wall got its first coat of primer, along with all the joints between the walls and the floor. I patched the hole I had made for plumbing, and made a teak insert to close the "hole in the wall" and support the bulkhead. Primer doesn't level itself well, but in the picture it looks OK. The right side wasn't in the plan, but I had primer left over, so I used it with almost no prep. We'll see how it sticks. Interlux Pre-Kote literally smoked me out of the boat. Short day.

In February a piece of teak was glued and glassed in to support the bulkhead and close the gap between the main cabin and the head, glassing and filling in one go. Not perfect: the filler will be sanded later. From the main cabin side it's just glass. Not superb, but it works.

White walls

Then we painted the head walls. Here they are side by side, new and old. Prep done, ready to go. A lot of work, and nothing to show for it yet.

It was mostly practice in roll-and-tip, and I'd give us 4 out of 5. Looking back, we needed more brushing thinner. But it's white! My wife Maria did most of the prep and painting. I only did the tipping, so all the imperfections are mine. The masking tape stayed on for a couple of days to let the paint form a good film.

And one more view of the boat from behind. It's hard to see in photos how beamy she is. I like beamy girls.

Cabinet, light, door

Then I rebuilt the head cabinet. The countertop panels stick up half an inch, so spilled water can't soak into the plywood edges. The right wall is glassed to the hull and deck with one layer of 1708.

In August the overhead liner and the light went in, plus a channel for the mast wiring. I'll cover it with the same white PVC as the headliner, or with plywood. Still thinking. And a temporary exhaust fan blows the head air out through the dorade box.

In October the trim was done. Only the mast cable area on the side was left to close. Here's what it was, and what it is now. The cables go up to a box in the corner of the ceiling.

And a bonus. This photo is taken from the height of the water that was inside the boat when we bought her, in November 2021. Think about that for a second.

When I bought the boat, the head door was gone. Time to make one. I wanted something like an airplane toilet door, folding inward into the head. I made the panels and the side posts with the hinges, put it together, dry-fit it, adjusted, and it went in. Here it is open, and closed from inside.

In March 2024 the last piece of the headliner closed up the corner where the mast wiring comes in. The round hole is for a vent grille.

By December 2024 the head had been finished for a year. No magic: all the walls are glassed to the floor to make a real shower pan. The porta-potty stayed, for real emergencies.

A shower that doesn't waste water

Who likes the first 5–10 seconds of cold water, while the hot water travels from the heater to the shower head? And where does that water go? Usually down the drain. On a boat, every drop of fresh water counts.

So in June 2025 I made a controller that sends the cold water in the hot pipe back to the tank before you start. It sits in standby with a red light. Press the button, and it runs the water from the hot pipe back to the tank until hot water reaches the shower, then shows green: ready. Then the same button opens and closes the shower. Maybe a foot switch later. If you don't use it for 5 minutes, it goes back to standby. In the pictures the box isn't closed yet. But it works!

Before that I had an even bigger idea: a recycling shower. It would use the boat's pressure water and water heater, have a clean mode and a recycling mode, automatic temperature control, and cost under $350, plus a hair filter, a service rinse cycle and a winterizing cycle.

The design had two pumps ($130) and a small 8-liter tank, so the shower runs at least 30 seconds while the water recycles. The tank had a level sensor ($15) and three zones: 3 liters at the bottom to mix and control the temperature, 3 liters where the level is held while recycling, and 2 liters of safe overfill. Then seven electric valves at $5 each, about $20 of pipes and fittings, a cheap IP67 windlass foot switch ($15), and my own control board (about $95 with buttons, an IP68 box and two temperature sensors). For the second revision I designed an air/water separator from a 1-foot piece of 4-inch PVC pipe, with two water sensors at 1/4 and 1/2 height.

I wrote down every step: prepare, clean shower, recycling shower, finish, off, hot water purge, a service wash, and even winterizing with a gallon of antifreeze (or cheap vodka). In the end I cancelled the project. The simple controller does the job, and nobody on board was asking for recycled shower water anyway.

A real toilet, finally

I'd been thinking about a "right", wife-proof toilet for a long time. The porta-potty was fine for the occasional day sail. But once we moved to Kemah and started sleeping on the boat some weekends, there was a problem: carrying poop 200 miles in the car and dealing with it at home is not a solution. Especially when the marina has a free pump-out.

After a long time thinking, I picked the Dometic MasterFlush MF 7120, a 12 V electric macerating toilet. Comfortable, easy and reliable. The fresh water flush helps a lot with smell, and the macerator means smaller hoses and an easier install. Much closer to a home toilet.

The install went mostly fine, but not without surprises. First test: water on the floor. I pulled the bowl off and still couldn't see where it came from. In the end I took the whole unit out again and found it: water was dripping right out of the electric motor.

Return it, or fix it myself? I didn't want to send it back, wait two weeks, and take everything apart again. The bolts that hold the motor to the pump plate go through a wet compartment and are sealed with O-rings. The holes in the aluminum plate are big, and the motor wasn't centered, so the screws sat off-center, and one O-ring had slid sideways and wasn't sealing. I realigned everything, the leak stopped, and I finished the install. Here's the top view, to show how much space it takes.

From pee-poo in the face on day one to a wife-proof toilet: the head has come a long way.