Saturday, November 8, 2014

tiller conversion

Suppose, suppose... Suppose we had a tiller instead of a wheel. Wouldn't the cockpit be much more spacious, wouldn't the mechanical complexity be much less and the reliability much greater, wouldn't it be much easier to feel the boat and balance the sails, and wouldn't a wind vane and self-steering be much more effective? All good reasons but when we suggested the conversion to most of our sailing friends, they thought we were nuts. In fact, if you do a Google search for "tiller conversion," what you will find is a long list of links to information for converting from a tiller to a wheel and not the other way around. Nevertheless, we decided that it was a modification that we wanted for SV Suppose and plunged into it. This was a "small boat project" but was definitely not a small project. However, the outcome justified the decision to proceed.

Note: This project is very similar to the one completed on Far Reach (Cape Dory 36). I exchanged email with the owner of that boat several times and he was a great source of advice and encouragement. The web is really an amazing community.

The first step was just to determine the feasibility of the conversion. Like virtually all of the Alberg designs, the Cape Dory 31 has a keel hung rudder. A cover plate at the back of the cockpit can be removed for access to the rudder post and installation of an emergency tiller. That was perfect for the conversion.

Edson Marine has an excellent selection of bronze components for both tiller and wheel steerage systems - not cheap but very nice quality. I ordered a tiller head and a rigid shaft coupler. Then, I expanded the hole above the rudder post and cut an access hole in the front of the aft locker. Our rigger turned a wooden dowel the same diameter as the rudder post and I used that to trial fit the components. Once I was satisfied that it would all work together, I asked a local vocational tech school to fabricate the stainless steel rudder post extension.

In the first picture above, you can see the corrosion at the base of the steering pedestal. We could tell that it wasn't solid and therefore, not safe for offshore passages. It was the corrosion that convinced us that we needed to either replace the pedestal or convert to a tiller. The costs were roughly equivalent so we opted for the tiller.

The next task was removal of the pedestal and steering gear or in this case, demolition of the pedestal. It literally disintegrated into dust when I tried to lift it. Our decision to replace it was certainly correct.

Unfortunately, after removing the pedestal, I discovered that the core in the cockpit floor was water saturated and would have to be replaced. I used an oscillating saw to cut through the upper fiberglass skin around the perimeter of the floor. It lifted off with very little resistance. Then I scraped the soggy plywood core off of the lower skin and gave the whole area a couple of days to dry. After covering the skin with thickened epoxy, I laid in a new plywood core and used wood screws installed from underneath to pull the fiberglass skin and plywood together. That was followed by two layers of fiberglass cloth, a layer of fiberglass mat, and another layer of cloth, all thoroughly impregnated with epoxy. The result is a very solid cockpit floor.

To fill the recess that I had created in the aft locker, I "stitched" a rough plywood box together and epoxied the joints. After using a belt sander to round all of the corners, I gave it a couple of layers of fiberglass cloth and epoxied it to the inside of the front face of the locker.

We spent several hours playing with the feel of various shapes for the new tiller. When we were satisfied, the rough form became the template for the ash and mahogany laminations. For this step, our rigger's assistance (Coastal Bend Yacht Services) was invaluable.

After the epoxy had cured the rough tiller blank was run through a thickness planer. Then it was just a couple of hours work with a belt sander, rasp and several grades of sand paper to bring the tiller to its final form. That was very satisfying work.

This is the final result. With a coat of paint on the cockpit floor, it will be hard to tell that this isn't a factory installation. The tiller works great and we are enjoying it a lot.

chartplotter support

As we upgrade and outfit SV Suppose for cruising, we have tried to keep things as simple and bulletproof as possible. In particular, we want to minimize the number of things that, if broken, would keep us from departing from one anchorage and moving on to the next one. So, we have given a lot of thought to the electronics, weighing functionality against complexity and reliability. In the end, we decided on the Garmin VHF100 radio, GPS820 chartplotter, and AIS600 transceiver. By buying all Garmin products, it was "relatively" easy to interconnect them so that we can see AIS targets on the chartplotter and provide gps data to the VHF radio so that it can transmit a distress call with our location at the press of a button. We don't have radar now but the GPS820 can support it if we decide to add it later. So far, we couldn't be happier with this combination.

As with every other addition or modification to SV Suppose, the challenge was finding the space for the new electronics.

The VHF radio was the easiest and first component to install. I simply replaced the old one which had been mounted against the cabin top, just inside the companionway on the starboard side. Mounted there, it is out of the weather and can be seen, operated and heard from the cabin, companionway steps, and the cockpit.

This is the chartplotter on the mahogany support that I built for it. Here it is in its "stowed" position where it is not in the way for normal activity in the galley.

The AIS transceiver, mounted below the chartplotter, is just visible in this picture.

We don't have a separate navigation station in SV Suppose. Instead, we use the removable counter-top that covers the stove when it is not in use. For operation from this "navigation station," the chartplotter rotates out approximately 30 degrees. The chartplotter support is mounted on an 8 inch, brass piano hinge attached to the side of the companionway frame. To get the support to rotate in a horizontal plane, I placed a wedge under the hinge and against the companionway. The 8 inch vertical portion of the support and the diagonal brace underneath provide a very solid and sturdy base.

The chartplotter and its support will rotate a full 180 degrees where it faces into the cockpit. The base under the chartplotter is shaped so that it rests against the vertical frame of the companionway and overlaps the threshold. This provides extra support in case we should fall against it. It is held in this position by a nylon "bump" on the bottom of the base that slides over the companionway threshold which is a little higher on the inside edge.

The chartplotter support is held in the stowed and 30 degree positions by this block that is mounted on the inside of the companionway bulkhead.

A toggle that rotates against the vertical portion of the support locks into two positions against the block. The dowel stub in the top of the toggle makes it easier to rotate the toggle with a fingertip.

And here is the base rotated to the 180 degree position. In this picture, it is easier to see how the shape of the base allows it to swing around the side of the companionway and overlap the threshold.