The Head:  Page 2
This page was last updated on 6 March 2002

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Installing the Lavac Popular Marine Toilet

I finally ordered a toilet for the head, after putting it off for months.  I ordered a Lavac Popular from Defender, after much thought.  While I have no direct experience with these vacuum-flush heads, I have heard only good things, and the simple design seems almost too good to be true.  Struggling with a marine toilet is not one of the things I plan on spending my cruises doing!  Besides, they come highly recommended by James Baldwin of Atom fame.  The toilet is currently on order; Ill post details of the installation later on.

I copped out on the holding tank for now. (See below for an update.)  There is just so much to do, and I can't bother myself worrying about the best holding tank installation.  Therefore, I ordered one of the flexible bladder tanks, which I have heard nothing good about, but for now, at least, it will meet applicable regulations, which is all I care about at this point.  I expect to replace the tank and reengineer the whole system in the future, but not right now.  There's no time to reinvent the wheel.

I installed the toilet with four lag screws and silicone.  It's a nice, clean installation, with plenty of room remaining.  Once the unit was screwed down, I moved on to the hoses.  I used white sanitation hose for intake and discharge--it is awful stuff to work with, as it is very stiff and hard.  The intake line runs from the seacock, through the bulkhead, and into a high loop inside the cabinet, then back down inside and emerges just behind the toilet.  This is a required feature of the Lavac, and there is a special air vent that is installed in the top of the loop. (Click the thumbnail below)

a5intakevent.JPG (143445 bytes)

I had hoped to run the discharge hoses inside the locker as well, but upon reading the installation instructions for the included Henderson pump, I noted that I had to mount the pump vertically--I had hoped to mount it on the platform next to the toilet.  I ended up mounting it on the aft bulkhead, which keeps the hoses hidden from view when in the salon.  The discharge from the toilet runs up to the bottom side of the pump, then above the pump into a high loop before returning down to the Y-valve, which I installed next to the pump.  From the valve, one hose leads to the overboard discharge; the other snakes around and disappears inside the locker before running forward to beneath the port vee berth, where the holding tank will soon be installed.  I tried to keep the hoses as neat and unobtrusive as possible--but there was no avoiding having them exposed for my particular installation.


I tested the head once the boat was in the water.  What a neat system...except for the fact that, from the factory, the bolts securing the toilet bowl to the base, which joint is sealed with a gasket, were not tightened, so water leaked all over.  I had to remove the toilet from the sole and tighten the four bolts, which took care of the problem but was an unnecessary annoyance.  And boy, does that vacuum seal the lids--it takes 10 seconds or longer after pumping to be able to pry the lid back up.

After a season of use, we are very pleased with the head.  The one thing that we learned was that sometimes the lid or seat might be a little cocked out of position, so the seals wouldn't allow the vacuum to form properly.  This led to some long pumping sessions while trying to figure out why it wasn't working properly.  Once this very minor problem--and the solution (make sure the seat and lid are properly aligned before beginning the pumping cycle)--became apparent, we experienced absolutely no problems with head performance.

The platform on which the head is installed required a piece of trim on the outside to cover the edge of the plywood sole.  I milled a piece out of mahogany to match the other head trim and installed it with screws after finishing with tung oil.




Holding Tank

My original plan had been to cram a Nauta flexible holding tank into the tiny space beneath the vee berth forward of the head.  Sailing and enjoying the boat prevented me from getting into this project during the 2001 season, but once we  hauled the boat for the winter I knew that I had to come up with a solid, workable solution to the containment problem.  The flexible tank seemed to be out--too impractical for actual use.  It seemed the only solution was to put a tank in the space in the center of the vee berth.  This would mean giving up the nice drawers that I installed there, but I think having a decent, large, practical holding tank has to win this war.  We can find other storage space to make up for the lost drawers, but there's really nowhere else for a good-sized holding tank.

My plan for the waste system is to allow both containment and direct overboard discharge, and to make it easy to switch between the two as necessary.  I will also install an effective means of emptying the tank directly overboard when it's possible to do so, as well as to have an on-deck pumpout for shoreside facilities.  No matter how I plan it out, it ends up more complicated than I would like, but there's just no other way.  We certainly can't rely on shoreside pumpout facilities--they range anywhere from nonexistent to non-functional to horribly inconvenient at best.  I also want to minimize clutter and complicated hose and valve runs.

holdingtanksetup.jpg (20048 bytes)What I have come up with is best described with this really crude diagram I put together. (Please click on the thumbnail for full size.)  A draftsman or penman I am not, so I apologize for the presentation!  However, it gets the general layout across.  From the toilet, the flow runs through a Henderson MK IV manual waste pump--the one that comes standard with the Lavac toilet.  Next is a Y-valve that allows the flow to be directed to either the holding tank or directly overboard through the sea valve.  From the holding tank, there are three outlets:  a vent line, a hose that will run to a deck fitting for pumpout, and a final hose that runs from the tank, through a second Henderson MK IV waste pump, and to a second Y-valve installed in the discharge line between the first Y-valve and the overboard discharge.  

Thanks to a friend, I found a polyethylene holding tank that looks perfect for the space available between the V berth.  The tank is built by Ocean Link Inc. in Rhode Island, and looks to be of high quality--3/8" minimum wall thickness to prevent permeation.  The tank is # OLT-230 (right).  Note that this drawing does not show the exact shape of all profiles of the tank, but the dimensions are accurate.  I also found a tank of identical dimensions at Ronco Plastics.  Ronco's drawing fills in a couple details that this drawing (right) misses, so it's worth taking a look at. What I haven't figured out yet is if the construction is the same.  Ronco's tank (# B115) is somewhat less expensive, but I fear it may have thinner walls.  I will definitely go with the thickest walls, but if the two tanks are constructed the same, I will choose the less expensive one.  Research is underway at this time.

After seeing Ocean Link's tank in person, I decided to go ahead with it.  I ordered the tank with two dip tubes for the double discharges, a single inlet, and two vent fittings--along with the requisite PVC and hose fittings (See  below).  Construction of the tank is underway and I expect it in a couple weeks.  The tank was very pricey.  I have all the other materials required for the job on hand.

Installing the Tank

Before installing the holding tank, I had to take care of a small issue.  The hose connection for the fresh water tank is normally accessed through the little hatch on the sole of the vee berth--directly beneath where the holding tank will sit.  Now, removal of the tank in order to replace this water hose every 10 years or so is OK, but I like to remove it to drain the water tank at the end of the season, or whenever else it seems necessary.  Obviously, this was going to be impossible once the holding tank was in place.

To get around this, I bought a 3-way diverter valve (bronze) and installed it just downstream of the tank fitting.  I installed it so that I could reach it from the hatch in the cabin sole in the head.  Turning the valve one way directs the water normally into the supply hose for the two sinks.  Turning it the other way will drain the tank.  In the picture, you can't see the valve--it's below the bottom of the picture.  The hose on the left is the supply from the tank (the tank connection is at the top center of the opening), and the hose on the right is the water supply line running from the new valve back up by the tank and through the starboard side of the vee berth to the head  vanity.   Because of the tight space in the bilge where the valve ended up, I had to reverse the handle on the diverter valve.

My new tank was delivered right on schedule.  For anyone interested in the OLT-230, here are front, side, and back pictures of the tank as delivered:

olt230front.JPG (192336 bytes)        olt230back.JPG (176779 bytes)     olt230side.JPG (168937 bytes)  

The two openings at the back of the tank are the dip tubes for the pump outs.  In between them is a vent fitting.  At the forward end is the inlet opening, and a second vent.  They were not able to supply what I really wanted for the hose connections--simple 90-degree fittings with a hose nipple on one end and threads on the other.  (Read on for more on this.)  Therefore, I was talked into buying a series of PVC elbows, threaded inserts, and special pieces that insert into the PVC elbow and have a smooth hose fitting on the other end.  I was worried about the clearance above the tank, but went ahead with the order for these pieces.

To get the tank to fit in the opening between the vee berth, I had to remove a couple of the cleats that were installed to support the vee berth filler pieces--I had to remove the middle section, and one of the side pieces.  Once I did this, the tank slid in perfectly, with only about 1/2" of movement possible in a fore and aft direction without the need to add more braces.  I will add some additional braces to prevent the tank from moving at all a little later in the process.  It really is a perfect fit...amazing that it's a stock tank!

When I test-installed one of the supplied PVC elbows and inserts, of course I found out that they took up too much vertical space, and the plywood filler piece would not fit over the top.  It was close, and I probably could have routed out a bit of the bottom of the plywood or something, but no, I had to go on a quest for the 90-degree fittings I had been looking for at the beginning of the process.  I drove to the hardware store, but they didn't have anything.  They have the straight version, but no elbows.  None in the catalog, either.  It never fails that they don't make the fitting I am looking for.  I continued on to West Marine in search of something else.  I found two Marelon tailpieces that were fine--but I needed three.  I looked at the selection for the longest time, but didn't see anything else suitable.  Then, I turned around--and on the other side of the aisle, there were some holding tank accessories.  Among the stuff was a Todd conversion kit that contained two nylon 1-1/2" elbows that were threaded on one end with a hose nipple on the other!  Bingo!  I bought the kit, and one of the Marelon tailpieces to round out what I needed.

Please click here to continue the project.

Glissando, Pearson  Triton #381

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