Wednesday, January 13, 2010

Tinkering with the best-laid plans

My intent to experiment with the Birdwatcher design had to do mostly with the sail rig, which I will deal with in its own post. As for the boat itself, I did not plan to deviate from the drawings, and didn't much. The Birdwatcher is a great boat as is. But once you get into the dust and screws of a project, you start to think about how things could be tweaked differently. Here and there, I found a few ways to construct the Birdwatcher more simply, and more strongly.

As I mentioned last time, the basic hull comes together very quickly. You position the frames on a strongback, plumb and square them up, scarf together the side panels and hang them on the frames and screw them into the stem and stern pieces, and before you know it you've got something boatish.

You can build Birdwatcher with the chine logs inside, outside, or none at all, relying on epoxy alone. I chose outside logs because it seemed a good idea to have some lumber where the boat was likely to take a hit. When a sharpie heels over to sail, the chine becomes a keel. I read somewhere that exterior chine logs also gave you a toehold to climb back aboard if you go for a swim, planned or otherwise. In practice they do, though it takes a lot of upper body strength to climb up even in ideal conditions. Re-boarding would be nearly impossible without the external logs.

I had already decided to at least give leeboards a try, so I did not build a centreboard right away. I determined, however, that if and when I did put in a centreboard, it would go on the port side, not to starboard as Phil Bolger showed it on his drawing. I never got a chance to ask Phil his rationale. Mine was this: the mast is stepped on the same side as the centreboard. You hoist it onto your shoulder and walk it upright. I figured it would be better for a right-handed person to have the mast on the left shoulder, so when you get it into position, you have your good mitt available to toggle the mast partner lock closed. In practice this is true.

The use of polycarbonate (Lexan and other brand names) for the extensive windows was problematic.
The material itself if brutally strong, much more so than plywood of the same thickness. You can hit it with a framing hammer and it won't break. But it is difficult to affix to a wooden structure because its thermal expansion rate is large. Bob Larkin has done some great work on this and posted useful information on his Birdwatcher II website -- which I did not see until much later. I just drilled oversize holes, almost a quarter inch. They require some sort of washer, and I used faucet stem washers from the plumbing aisle. They work and are cheap, but crack after a season. I need to find something better. The fasteners, about one every 10 inches, hold the polycarbonate against weather stripping. In practice, the assembly is not entirely tight and will seep if you heel the boat right over so the windows submerge. I am not quite comfortable with the strength of the windows still.

The plans call for polycarbonate on aft sections of the top deck as well as the sides. This overhead window is for keeping an eye on sail trim. I chose to use plywood down the whole top deck for a number of reasons. First, sitting in my unfinished boat, I realized that the sails would be easily viewable on one tack without a window, and on the other tack just by leaning forward and having a peek. Besides, this is a cruiser, not a racer. In a ten-hour day, you won't want to watch the trim that closely, believe me. And once you know the boat, you can feel out-of-trim in the seat of your pants. The plans specify plastic on the angled part of the top deck too, but these areas are so tiny that the windows add little to the view. Second, using all wood on the top would increase the strength enormously. Third, there seemed no good way to make the top very watertight where plastic met plastic. Fourth, the top is where you lash the rig at night, where you cook and fillet fish and sometimes stand. It takes a beating. Finally, it seemed the helmsman would be happier without the sun beating on his head. All these things have proved true in actual practice.

The last consideration for the polycarbonate: how dark should it be? The stuff is very expensive, so you don't want to buy it twice. Some people have used it clear, or just barely tinted. Aesthetically, I much prefer the darker look, about as dark as a pair of sunglasses. It makes the boat look all of a piece. In practical terms, it affords more privacy. A strong tint hides the blemishes that polycarbonate gets as soon as you start using it. You might worry that the dark stuff will impede the view, be a disadvantage in low light. On the contrary, we just don't realize how terribly bright it is outside, especially over water. It is very relaxing sailing behind strongly tinted windows. In fact, they don't seem strongly tinted at all, but just right.

Two other small changes. I did not build the integral wooden anchor chock on the bow as shown on the plans. It just looked too complicated, would take a lot of upkeep, and metal anchor rollers are cheap and easy to buy. I built both the stem and stern as Phil Bolger specifies on so many other boats -- but not this one -- with a true stem or stern piece inside the hull panels, and false ones screwed to them outside. The drawn ones were more complex in order to be more economical of lumber.

As for the Birdwatcher's oar ports, I bought ready-made ones from a chandlery, which seemed the easiest route to leak-proof assembly near the waterline, plus I could see through them. These opening ports would turn out to be useless for their stated purpose -- this boat is just too big to row effectively. I had read as much before building but, as a competitive rower, I felt like I would be capable. In practice, rowing this boat is demoralizingly difficult, especially from the position Phil Bolger specified. You are so far aft that the boat is uncontrollable in any kind of cross wind. Even in a flat calm, the boat tracks very poorly. I think two rowers standing fore and aft could handle the boat in some wind, but that would mean four long oars and locks, which take up a lot of room in a small boat and add up in cost. I will return to this topic later, but want to introduce it now in case anyone who reads this is about to install oar ports. At least hold off awhile, because the whole subject of auxiliary power in this boat has been the subject of major re-thinking by Phil Bolger himself -- he drew Birdwatcher II to address this issue. And that, too, will be addressed in a later post.

My ports may be useless for rowing, but they are invaluable for ventilation at night. You can have them wide open in a pounding rain and not a drop comes aboard. You can wake from sleep, prop up on one elbow and get a quick look out to check your anchor is holding, or what the overnight weather may be doing.

Finally, I built some handsome little cupboards for stowing small items and installed these at the middle frame position, at the widest part of the hull. Fortunately I made them removable, because they were useless. I failed to consider that the middle frame is also the deepest part of the boat and thus where the bilge water gathers. If you have cabinetry there, rainwater or spilled tea runs right underneath and can't be sponged up. They also take up a cozy space right next to the helmsman where someone could snuggle in,  thus diminishing the romantic capabilities of this boat. Maybe the idea of sailing with your arm around someone has no appeal for you. But have a thought for the future generations who will inherit your boat!

No, I think this boat is too small for furniture. I have found it much more practical to load the boat with Rubbermaid tote containers. These can be wedged into place for sailing amidships for sailing, then re-positioned for camping afloat. If you camp ashore, these boxes are essentially rain-proof and damp-proof.

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