Compass, Part 2: Installation of Mahogany Panels

The Ritchie SR-2 Venture compass, dry-fitted in the mahogany panels in the cabin trunk
Having constructed the mahogany panels for the new compass in Oystercatcher, my Ericson 25, it was now time to install them, or at least to dry-fit them into place. In this second of three postings on the installation of my new Ritchie SR-2 Venture compass, I describe the steps I took to install these panels - these panels that would serve both a practical purpose and an aesthetic one.
From a practical standpoint, it should become immediately obvious from one glance at the picture below that these panels served to conceal the original compass hole. Not only was the original hole smaller than the hole that was necessary for the new compass, but also it was not well placed. For some odd reason the installer had decided to mount the compass quite close to the companionway way. Given, however, the other odd installations that were here and there around the boat, this was not surprising. Is it really that hard to bring forethought to a project? In other words, is it really that hard to sit back, imbibe a glass of hops and barley, and think through a small project from beginning to end? Why do some feel the compulsion to go tearing into something with hell-bent abandon without weighing the pros and cons of one approach or another? I'll never know.
The interior panel, partially installed.
As seen from afar. Pay no attention to the plywood and cardboard around the stove. These were mock-ups I had created in an attempt to figure out how to protect the electrical system in this area of the galley. I would later abandon this plywood approach and would adopt a fireproof, protective curtain approach.
At this time, I also experimented with the mounting of a second mahogany panel on the interior side of the cabin trunk. I thought it might be good to mimic the panel that I had applied to the other side for the mounting of a binocular rack. I did not plan to mount a binocular rack on this side (since it would encroach upon the stove), but I thought it might help to balance things from the visual standpoint. After taking a little time to think through this, I decided that this area would look better without the extra panel. It made things a little too busy looking, and it really served no practical purpose.
Before abandoning the idea, I experimented with orienting the extra panel vertically, so that the ribbon stripes would match the top panel. I didn't like this look either. Too much accentuation of the vertical.
Just as was the case with the panels for the GPS, these panels for the compass would just barely cover the original hole. This was one reason why I needed plenty of screws in these panels. The panels had to be nice and snug against the cabin trunk.
I used my Makita jig saw with a reverse-cut blade (Bosch T101BR) installed, so as to minimize the damage to the gelcoat.
For the installation of the panels, I used the cockpit seat as a reference
This turned out to be a bad idea. I should not have assumed that the seat was level. As you can see in the picture below, the panel is clearly not level.
Fortunately, I was able to widen a few of the holes that I had already drilled in the fiberglass. This allowed me to correct the panel.
This made things much better.
Now that the panels were installed, or at least dry-fitted into place, I could focus on my next task: installing the panels with adhesive/sealant, and then installing the compass itself into its new home. These steps are the subject of the third and final posting regarding the new Ritchie SR-2 compass that I added to Oystercatcher, my Ericson 25.

Compass, Part 1: Construction of Mahogany Panels

The mahogany panel for the mounting of the Ritchie SR-2 Venture compass
The importance of a reliable compass on a cruising sailboat cannot be underestimated. I have spoken at length about my stance on the importance of this instrument in my article, "Electronics, GPS and VHF, Part 1: Traditional Navigation," so I will not revisit that argument here. Instead, I will simply address the basic steps that I took to install the new Ritchie SR-2 Venture compass in my boat. In the first part of this three-part article, I address the construction of the mahogany panels for the mounting of the compass; in the second part, I address the installation of these panels; and in the third part I address the installation of the compass itself. This project, as you might have guessed, was part of a larger project involving the replacement of the electronics, which itself was part of the overall refitting of this boat for the purpose of extended cruising. Throughout this refitting, of Oystercatcher, my Ericson 25, as I have said many times before, I was guided both by practical concerns and aesthetic concerns. These concerns, therefore, were of no less importance on this compass project than they were on any other.
The compass that came with the boat when I purchased her in the fall of 2009 served no practical purpose, and it certainly did nothing to enhance the beauty of the vessel. If anything, it detracted from its visual appeal.
The compass light did not work. Its wires had long ago succumbed to corrosion.
After a good bit of research, I settled on the Ritchie SR-2 Venture compass. I liked the Richie reputation, and I like the fact that this particular model was made to be mounted on an angled cabin trunk such as my own.
Earlier, I had installed a GPS on the starboard-side cabin trunk. For this installation, I had created a mahogany panel. This panel served a practical purpose and an aesthetic one. It allowed me to cover the old instrument holes, and it provided an attractive trim for the new GPS. For more on this project, see the above mentioned article.
I also created a second mahogany panel for the interior for the GPS. This panel served the same two purposes.
I really liked the way the mahogany looked on the cabin trunk, so when the time came for me to install the compass on the opposite side of the trunk, I decided that it would be nice to create a panel of the same size and shape for the mounting of the compass. This panel, as we shall see, would serve the same practical and aesthetic purposes, insofar as it would conceal the old compass hole and it would provide an attractive trim to the instrument.
The first step I took in the construction of the panels was to plane down two pieces of 4/4, i.e., 1 inch, mahogany to 1/2 inch.
Below we see the two GPS panels sitting atop the 4/4 mahogany. I would use these GPS panels as patterns for much of this part of the project.
The freshly planed 1/2 inch pieces of mahogany. These pieces came from two different boards and probably two different trees. Note that one is lighter in color and possesses a different grain pattern.
The darker piece would go on the exterior of the cabin trunk, and it would complement the darker trim piece for the GPS.
The lighter piece would go on the interior. The pronounced ribbon stripes would complement the other pieces of ribbon-striped mahogany in this area of the boat.
I used the holes in the GPS panel as a guide for the drilling of the holes in the compass panel.
I wanted to make sure that the compass cover and the clinometer fit on this panel. As you can see, they fit quite well.
The Ritchie company was kind enough to provide a template for the mounting of the compass. I used this for determining where exactly I needed to cut the hole in the panel.
Even though the panel was only 1/2 inch thick, it was still a chore to cut through it with this large hole saw.
After I cut the hole, I drilled the four holes for the plastic screws that would secure the compass to the panel. Note also the notch along the edge of the circle. This notch was necessary to make room for the wires. These wires, of course, would supply the compass light with power.
The compass fit just right in the hole.
Using the exterior compass panel as a template, I marked the holes that I needed to cut and drill on the interior panel.
The interior panel with its new holes.
Notice that I made the interior panel slightly longer than the exterior one. I did this so that it would match the size of the interior panel for the GPS on the other side of the galley.
My final task was to round the edges of the panels. These curves gave them a nautical touch, since right angles are a rarity on most vessels, especially the most attractive ones.
This ends this posting on how I constructed the mahogany panels for the Ritchie SR-2 compass that I installed on Oystercatcher, my Ericson 25.

Electronics, GPS and VHF, Part 6: Transducer Installation

The Airmar B60-12 transducer, fully installed
A transducer is a useful electronic device on any sailboat. Without a transducer, the mariner is left wondering what the depth of the water might be. Of course he could use a lead line to determine this depth, as mariners before him did for centuries (and as some mariners still do), but the transducer has the benefit of providing an instant indication of depth - information that could help him quickly steer clear of water too shallow for his keel or centerboard. Some transducers bring with them additional benefits, such as temperature readings. Such is the case with the Airmar B60-12 transducer, the type of transducer that I installed in Oystercatcher, my Ericson 25. In this posting, I describe my rationale for selecting this particular transducer, and I describe the various steps that I took to secure it to the hull.
The location that I selected for the installation of the transducer was within the largest of the three lockers in the V-berth area of the boat.
This through-hull transducer in the V-berth would relay its information to a Garmin brand GPS (GPSmap541s) in the cockpit. Garmin does not manufacture its own through-hull transducer for this GPS. Rather, it tools its GPS for the Airmar brand transducer.
As I said in earlier postings in this article, I opted to use a flush-mount kit for the installation of this GPS. This meant that the face of the GPS would be oriented toward the cockpit and the back of the GPS would be exposed to the galley. In the picture below, I am making sure that the transducer cable fits the appropriate connector in the wiring harness.
This transducer was of heavy-duty, bronze construction and contained a lengthy cable. I opted for bronze instead of plastic because of its durability. I opted for a through-hull style transducer because this style are more accurate than other styles. Was this transducer expensive? Yes, but I got for about half the suggested retail price through price-matching at West Marine (back when West Marine still did this sort of thing).
Also in the box with this transducer was a rubber gasket. This gasket would of course sit between the nut and the hull on the interior of the boat.
The Airmar B60-12 carries the number 12 designation to indicate that it can accommodate a hull with a deadrise up to 12 degrees. I liked this "tilted element" feature of this transducer. It meant that I did not have to install a wedge-shaped block of teak on the hull to level out the instrument.
Before I ever purchased this transducer, I had determined that the deadrise of the Ericson 25 is 12 degrees.
At the time of purchase in the fall of 2009, this boat had two different instruments in the aft locker of the V-berth: a defunct transducer (pictured left) and a defunct paddle-wheel knotmeter (pictured right). As I described in my four-part article "V Berth, Aft Locker, Holding Tank Shelf," I removed the knotmeter and filled the hole with fiberglass. This was where I would install the holding tank shelf.
Also, as I described in that article, I removed the old transducer for the purpose of replacing it with this new one, i.e., the Airmar B60-12.


Likewise, I described in that article how I enlarged the old transducer hole to make room for the new instrument.


After I had installed the infrastructure to support the holding tank and a large storage shelf in this space, I applied two coats of two-part paint. All of this I documented in the above-mentioned article.
In the midst of my work on the holding tank in the aft locker of the V-berth I had sanded the hull and applied two new coats of bottom paint. For more on this, see "Hull, Bottom Painting." Now it was time for me to rough-up the area around the exterior of the hole in preparation for the installation of the transducer.
With that quick and easy job out of the way, I proceeded with a dry-fit of the transducer.
It's important to orient the transducer correctly. Otherwise the tilted element within the instrument will not tilt in the manner that it should.

Before I inserted the transducer into the hole I wiped the bronze with acetone to remove any oil that might have been on the surface from the manufacturing process. Did I pick up some residue on my cloth? Yes.
The transducer fit just right. Note that the plastic cap on the top of the transducer makes the orientation of the instrument idiot-proof.
Not only has Airmar placed an arrow that points toward the keel, but also it has constructed the cap in such a way that the cable must point toward the keel.
Satisfied with the dry-fit, I moved forward with the installation. For this, I enlisted the help of a buddy. One of us held the transducer, the other applied Sikaflex 291 LOT (Long Open Time) polyurethane adhesive/sealant.
Then, one of us inserted the transducer, while the other went inside the boat to secure it with the nut.
Very little of the Sikaflex from the exterior made it to the interior. Therefore, it was necessary to apply some of this adhesive/sealer in the area where the nut would sit against the hull.
Tightening the nut was a one-man job, but it was a job that required a set of Channel-Lock pliers in each hand. The small set was for holding the transducer still. The large set was for screwing the nut down tight. For those who might wonder how the small set did not damage the threads on the transducer, I should note that there are two flat spots within the threads that are designed to accommodate a set of pliers. In terms of the tightening of the nut itself, I should mention that it's important not to screw it down too far. Otherwise, the nut will distort the rubber gasket. I myself went a little too far, and as a result, had to back it off a little bit.
Outside the boat, I cleaned up the excess Sikaflex with a plastic epoxy stir-stick and a rag moistened with mineral spirits.
I did the same thing inside the boat, shortly after I snapped the picture you see below.
All in all, after I had completed all of the prep work, the installation of the Airmar B60-12 transducer in Oystercatcher, my Ericson 25, was pretty simple.