An Overdue Upgrade

LavacA few days ago I spent 12 hours removing our old head and installing a new Lavac. We had retrofited a Lavac on our 1977 Columbia 8.7 in 1983 and never had to repair/replace anything before we sold the boat in 1992. (The bowl on that one was Royal Dalton China!) We found the operating principal to be pretty much flawless. We bought another to install in our Freedom 40 in 2003, but sold the boat before I could do the work. These devices are of such quality we sold it for 85% of what we paid.

Jump to 2008. When Brilliant Star’s forward head finally succumbed to its design — too many moving parts in a very hostile operating environment — I rebuilt it. When it failed again, I replaced it in kind just because it fit the mounting holes and hoses in the boat. When number 2 (the head) failed the same way (and why not), we said, “enough,” and more vigorously than that, I can assure you.

After living with the partial failure — it worked, just badly — for two months while researching alternatives (and dealing with bureaucracies), we decided to buy another Lavac. Our mail service is the US distributor. They are only about a three hour drive from here. I called and said, “send me one.” It was here the next day.

But the weather wasn’t favorable for the job, and we wanted to celebrate Valentine’s week checking out the area. On the 15th the weather turned beautiful and…

Once I had moved cabinet contents out of the way and removed cabinet doors for ease of access, it took very little time to get the old head out (lots of practice). It took very little time to remove the old waste hose — a trick here — use a thru-hull wooden emergency plug to plug the end of the hose after pumping through copious cold water. Keeps the bad stuff under control. It took a bit more time to set the Lavac up for installation. It comes arranged for a particular installation orientation, and I had to rotate the base 90°

hoseIt took HOURS on HOURS to route the waste hose from the head bowl to the pump to the stainless steel siphon breaker. The hose type that is most impermeable to bad odors (Series 148), is also not inclined to bend all that much. With its thick walls and nylon reinforcement coil, it comes with a permanent “set” from being on a spool.

Yes, it can be bent to a “five inch radius,” but while holding the pressure to keep it bent, doing anything else with it (like fitting it to a barb or spigot) is very difficult in cramped quarters while working by feel. Much short word muttering ensued, before I resorted to a Spanish Windlass to hold the gentler curve I needed. It’s like working with an irritable python. And the arrangement of the Lavac components means the hoses must now follow new routes. This was not a problem on the Columbia because we had a locker behind the head, and routing the hose through there was trivial. Here, we have blind spaces and limited clearance and a few obstructions. So, I had to get out the Dremel tool and its side cutter bits to create new paths. Then the hose must be nearly boiled or hit with a hair dryer blast to soften it enough to get it to slide onto fixed fittings.

And then I had to re-route the supply line as it was getting water-locked. My bad.

What’s so great about these heads? The head itself has no metal moving parts. The pump, a repurposed, large capacity bilge pump, can pump almost anything. The joker valve is three lobe, not two and therefore, is less jammable. It is nearly impossible to clog these pumps. The flapper valve, 100% nitrile rubber that simply flexes to open and close, needed some breaking in to seal properly after pumping, but it finally did.

But it’s the operating principal that is key. The cover and seat each have a soft, circular gasket. When one pumps, it creates a partial vacuum in the bowl. This sucks in flush water. When pumping stops, the siphon breaker (no moving parts) in the flush water supply line drains a bit of water to the bowl which opens an air path breaking the vacuum which  allows the lid to be lifted. A couple of pump strokes and any remaining flush water (except for a few tablespoons) is gone from the bowl. The water in the hose creates a true odor block not achieved by the previous head.

No pistons, no piston seals, no piston shaft seals, no “flush”/”pump dry” valves with springs in salt water, no check valves, no metals exposed to sewage, and no geyser-like back burp (really bad juju) when the flapper valve sticks open. You get the idea.

2 responses to “An Overdue Upgrade

  1. Hi Chris,

    Excellent entry (as usual!)

    We had the older Lavac on our first boat for 18 years. They are indeed tough and reliable but the seat cracked at one point… I think the new ones have fixed that with a much tougher seat. And I bet I know the name of the brand you kept rebuilding 🙂


    Paul Shard – SV Distant Shores II

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s