I’ve been lazy with postings and finally catching up.
We completed the head install about 3 weeks ago with the exception of final vent fittings and cosmetic touch up.
Lesson number 1: Venting
Venting should not be overlooked. The original vents for both heads are made from old plastic tubing that became very brittle over 30 years of exposure to holding tank gasses. They were broken in several places resulting in unsavory smells… All lines need replacement. We decided to upsize the original 3/8″ line and go with 1/2″ PEX to increase airflow.
This sounds easy, right? The boat was designed well with all venting leading to the transom. The theory is that this keeps all holding tank gasses out of the boat and cockpit. On a 46′ boat, this means you have a vent line running almost 50′. There is a conduit which was helpful (which was the limiter on ventline ID), however it was in 3 non-contiguous sections. That means you take apart a lot of the boat to run the lines.
The line is run and I just need to connect to the holding tank with a new thru hull.
Lesson #2: KISS
We went with Lavac toilets as we liked the simple design. Easy to service and all pumps are based on common components. Rumor has it that the toilet has survived flushing stuffed animals (had to be tiny) through it.
The plumbing was not so simple. We created an all new system that included:
- Vented loops on the saltwater inlet and head outlet. Lavac toilets use vacuum to pull in saltwater for the flush and need a vacuum break. The head outlet vacuum break stops your boat from sinking if a siphon forms while configured to dump overboard… this wasn’t needed on the previous toilet.
- Flexibility in waste management. Have 4 paths for our poop. Head to direct overboard (for offshore use), head to holding tank, holding tank to pump out and holding tank to overboard via manual whale MK5 pump. Two pumps, two Y valves and no power required.
- Common pumps. The toilet flushing pump is the same model pump used to pump offboard from holding tank. Common parts equals less spares. With the aft head, there will be four in total.
Note the pvc to hose ‘barbs’. I used SeaLand hose adapters and love them. Available online or at SeaLand/Dometic dealers for about 3 bucks, or West Marine for 19.99.
We are excited to have a working forward head again and can’t wait to start on the aft head.
Lesson #3: crappy 80’s plastic
During the plumbing project we discovered that the same brittle plastic lines are used for all the cold water lines, water tank vent lines and fuel tank vent lines throughout the boat. How did we discover this? We shattered one under the sink in the forward head while pulling sanitation hose. We also had a mystery puddle after filling the water tanks. They are all on the replacement list.
Stay tuned for more plumbing fun after our next project….Rigging!!