The Motorsailer Project

Project Log: Saturday, February 18, 2012

I spent the day largely on through hull duty, interspersed with other miscellany. As was so often the case, the list of tasks was straightforward, but planning for future installations and access extended the process.

To begin, I assembled the three bronze ball valves on to their respective bronze flange adapters. While it is more convenient to install the flanges without the bulk of the valve in place, pre-installing the valves meant that I could choose how to position the fitting and valve handle in the final installation--important so the valve handle ended up in an advantageous position, and also (to me) so the flange bases and fittings looked good and appropriately aligned/symmetrical when installed. Using a vice and large wrenches as needed, and with pipe dope on the threads, I installed the valves on each fitting the way I wanted them.

Within the limits of the cabin sole bilge access hatches I'd constructed, I determined the location for the new depth transducer. I decided to locate the transducer a bit forward of the old location, almost entirely because I remembered while scoping out the location that I'd never gotten around to installing fiberglass patches over the exterior of the original hole. Long ago, I'd filled the hole, and patched the inside, and even ground out around the exterior to accept the new material, but for whatever reason I'd not gotten to the exterior patching.

There was no compelling reason to reuse the old location; indeed, that's why I filled the old hole (and all old holes). However, I might well have used the same general spot except that to do so now would slow me down by a couple days, the amount of time required to install and fair the exterior patch. Though now seemed a good time to scratch this minor job off the list anyway, I didn't care to postpone installing the through hull while I completed it.

Instead, I moved the location slightly forward, which would tuck the transducer more toward the forward end of the access hatch, a plus for additional protection. After determining a location that allowed for the backing ring, as well as reasonable access to tighten the transducer nut, I marked the spot and drilled a small pilot hole through the center so I could ensure the location worked from outside as well. Then, I drilled the requisite 2-1/2" hole from outside. The hull in this area was approximately 1/2" thick. Later, I sanded away the paint from inside and outside as needed.

Moving aft to the engine room, I contemplated the three fittings I had to install: two cockpit scuppers and the engine intake. Here I had to do some advance thinking and planning to ensure the fittings weren't in the way of something later on, and also that I could maintain as reasonable working room as possible for all future maintenance tasks.

As elsewhere, I'd patched the original through hull locations, so I was not bound by them in placing the new fittings. I decided to move the scupper through hulls slightly inboard, further towards the keel, to keep the seacocks more out of the way and give me better access to the aft, outboard ends of the engine room. Also, the old locations were not symmetrical, which bothered me.

Before I could finalize the location, however, I got thinking about the engine exhaust and waterlift, and also about a potential platform spanning the hull aft of the engine--both for ease of working there and also (potentially) to support a waterlift. This tangent led me down the road of waterlift selection, where I analyzed the various choices to determine what shape and position might work best not only within the spaces available but also to attempt to maintain desirable height clearances to prevent exhaust backflow.

The ideal position never seems to make itself available in any boat, but eventually I determined a couple possibilities and, at the same time, discounted the idea of the shelf/platform for the waterlift and/or working platform across the shaft alley, since the height of the shaft would have made the platform too high to be worthwhile as a waterlift support, and also awkwardly high otherwise. The end result of all this was that I eventually determined--in spite of continuing questions about the exhaust system--that I could, and should, place the scupper through hulls where I'd originally intended.

After locating one, I took some basic measurements and located the opposite one in the same relative position, tracing around the backing block and the inside hole.

In addition, I now had to decide where specifically to locate the engine intake, not only for access but also for convenient hose runs to a sea strainer, and from there to the water pump on the forward side of the engine. Of course this is when I also realized that the raw water strainer was one installation I'd not necessarily planned ahead for in the layout of the engine room accessory panels, so to be sure I took care of that soon, I took a few moment to locate and order the strainer I wanted. I should have had it on hand before now, but I couldn't think of everything all the time, and this thing had simply slipped my mind.

Depending on the final layout of the fuel system components (which I'd be getting to soon), I figured the sea strainer would end up on either the starboard engine room panel, towards the aft end, or on a new panel just behind. Maybe if I had it all to do again I might have made room for the sea strainer forward of the fuel filter assembly, for potential access through the hatch from the cabin, but frankly I didn't think this was that important. Access would be excellent in my proposed location; I'd just have to lift the floorboard, which is pretty much how I anticipated dong any inspection or maintenance work anyway.

The net result of all these mental gymnastics was that I decided to install the engine intake through hull on the starboard side, just forward of the scupper. This would provide convenient and short hose runs to the sea strainer nearby, and the hose to the pump would just run where it needed to run. I positioned the fitting how I wanted it, and marked it. Afterwards, I drilled pilot holes so I could locate the fittings from outside before committing to their locations.

Next, I drilled the holes for the through hulls from outside. The hull in these areas was a bit thinner than down by the keel, about 3/8" thick.

Next, I dry-fit the through hulls, backing blocks, and flange/valve assemblies to determine how much, if any, of the through hull body length I'd have to cut off. As with two other 3/4" fittings I'd already installed, I determined that the engine intake through hull was short enough that cutting was not necessary.

However, the 1-1/2" scupper through hulls were much longer, and with the flange/valve assemblies threaded on all the way, there was a substantial gap representing the amount of extra thread length I'd have to cut off. I made some marks where the fittings came through the backing block and bottom of the flange; about 5/8" of additional length.

To ensure that the fitting wouldn't bottom out, I cut off about 3/4" on each of the two fittings, after which the basic pre-installation steps were complete.

After some final cleanup inside and out, and removal of paint as needed in way of any of the new fittings, I installed the backing blocks in epoxy at each of the four locations. To prevent any sliding while the epoxy cured, I held the blocks with some tape through the holes, and only installed the blocks at the end of the day so I wouldn't be on the boat and shaking things around.