Head Upgrade: Lavac, Holding Tank, and Teak Sole
Queen of Hearts came with a composting toilet. I had nothing against it in principle, but coming from boats with wet systems, I wanted something closer to what I was used to: a proper sea toilet, a holding tank for coastal sailing, and the ability to gravity drain offshore. That meant a full replumb of the head, two new thruhulls, a holding tank sourced from the UK, and a teak sole to finish it off.
The Original Setup
The composting toilet on the original plain fiberglass sole.
The System
The new setup uses a Lavac Popular toilet. The Lavac works by sealing the bowl with its lid and using a pump to create suction, which simultaneously draws in flushing water and expels waste. Waste is moved to the holding tank by an electric diaphragm pump. From there, it can either gravity drain overboard when offshore with the seacock open, or be pumped out at a marina.
The Holding Tank
Finding a holding tank that fit the Nor'Sea 27's head compartment took some searching. The tank needed to be vertical-mount to work within the available space and still allow gravity drainage. The Tek-Tanks 40 Litre Vertical Waste Tank fit the requirements. It is rotationally moulded HDPE with 10mm walls, a removable inspection hatch, and a gently sloped bottom to keep waste moving toward the outlet.
| Capacity | 40 litres |
|---|---|
| Dimensions | 400mm × 250mm × 550mm |
| Material | Rotationally moulded HDPE, 10mm walls |
| Mounting | Vertical bulkhead |
| Discharge | Gravity capable with seacock |
| Warranty | 5 years |
Tek-Tanks is a UK company. Getting the tank to the US required ordering through a US import company, which added lead time to the project.
Getting the tank into position was the hardest physical part of the project. The space behind the toilet is tight, and maneuvering the tank into place against the hull required some patience.
The Thruhulls
The project needed two thruhulls: one for the toilet water intake and one for the holding tank gravity discharge. The existing thruhulls were aging bronze and replaced as part of the work. New Groco bronze thruhulls went in both positions.
Each thruhull gets a custom backing plate to distribute the load on the hull. Rather than buying stock backing plates, I made triangular fiberglass plates to fit the available space, with studs for the seacock mounting.
Custom backing plates for the thruhulls.
Old thruhull out, new opening prepped.
Intake thruhull with seacock.
Waste discharge thruhull for the gravity drain.
The Teak Sole
The original sole was plain white fiberglass. To finish the head properly, I added a teak sole using a Nordic Teak SR5 Teak String Tile, a 19.6" × 19.6" rollable teak mat held together with rubber cording. The mat was trimmed on the table saw to fit the head footprint.
Cutting the teak mat to fit.
Results
The finished head is a significant improvement in both function and feel. The Lavac flushes reliably, the holding tank gives flexibility between coastal and offshore sailing, and the teak sole pulls the space together with the rest of the boat's woodwork.