Lofting the Deck and Learning to Love Imperfection and Accept Uncertainty

May 19, 2009

When I first decided to build a boat, I promised myself that I would work with great care. Each cut would be exact, every measurement precise. I believed that if I simply read the instructions and followed each step to the letter I would avoid mistakes. Every seam would come together; every angle would meet and match. It would be an exercise in Zen-like deliberateness: Chop wood, carry water, build a boat.

It didn’t take long for fantasies of perfection to evaporate. Joints didn’t meet, angles were slightly off, and (as I have recounted) the plastic resin glue dripped and gapped despite my best efforts to understand its properties. So even as the boat grows and takes shape, I see these mistakes multiply and become a permanent part of the craft, masked, but not erased, by sanding, putty, fiberglass and paint.

I should have known better. All craftsmen and craftswomen know that perfection is an unobtainable goal. Like “goodness” or “enlightenment” it can never by fully achieved by mere mortals. Even the most skilled builders, I suspect, can point to mistakes. Indeed, as our skills grow, so do our expectations, assuring at least a few disappointments along the way. Raising the bar encourages mastery, but guarantees that we will never be fully satisfied.

In an imperfect world, then, it’s useful to have some coping strategies. My mother-in-law, for example, frequently applies what she calls the “trotting horse theory” to her sewing projects. She rationalizes that if someone trotting by on a horse can’t see a mistake, it’s nothing to worry about. I eagerly adopted her sound philosophy to my woodworking projects.

But I had higher aspirations for my boat, partly out of pride, but also because I was consumed by a fear that errors would produce an unsound craft. I wanted perfection not only for its own sake, but because I worried that a boat without completely tight seams or flawless lofted hulls might go down as fast as a torpedoed Lusitania. Every time I perceived an unevenly cut board, I wondered if I had made a fatal flaw.

Part of this fear reflects a novice boat builders disbelief that an assemblage of plywood boards will actually result in a seaworthy craft. Since I don’t know how it will turn out until it is actually finished, I must accept, on faith, that all the cutting, screwing and gluing will produce a watertight craft capable of staying upright and moving forward under sail. Part of me doubts that such a thing is possible. Every small error increases the already high odds of failure.

My anxiety became the butt of jokes. “It’s a great father-son project, drowning in the middle of the Chesapeake Bay,” my oldest son taunted after helping me attach some stringers and listening to me fret about a sixteenth inch gap between boards.

But something happened to set my mind at ease. As “mistakes” mounted it finally dawned on me that I was setting up a standard that no novice boat builder could ever meet. If small errors spelled disaster, then it logically followed that the bottom of the ocean should be crowed with plywood boats. Yet the Internet is filled with picture of Pocket Cruisers, built by people less skilled than I, happily sailing on lakes and bay from coast to coast. If they succeeded, then I probably will, too. Maybe, I decided, I just don’t need to worry so much.

I also started to realize that “perfection” in the boat building world is not achieved through careful measuring and a close reading of the instructions. These things matter, of course, especially for first time builders. But boats—even simple plywood boats–are more complex and organic than most conventional carpentry projects. They are not so much assembled as they are shaped.

Indeed, woodworkers are often amazed and vaguely freaked out when they watch boat builders at work. Skilled builders are more like sculptors than carpenters; they are searching for pleasing lines more than right angles. Boards are planed according to the needs of the moment; the eye more than the tape measure guides the process. The most experienced may forgo plans altogether.

In The Saga of Cimba, for example, Richard Maury recounted how a Nova Scotia builder constructed his schooner “without so much as drawing a line on paper, or even whittling a model for a pattern. He had merely tacked together eight moulds, or life-sized cross sections, gauging them by eye, before immediately starting to build.” Not to put too fine a point on it, but that is not how carpenters or woodworkers are trained. One does not cut the leg of table “by eye.” We live by the maxim, “measure twice, cut once.”

My boat is more rudimentary and plywood boats are constructed differently than traditional wooden crafts, but there is a lesson here for me. I began with the assumption that all I needed to do was make the right measurements, screw Board A into Gusset B and a boat would effortlessly emerge. But when discrepancies popped up despite my best efforts, I panicked. How can I build a boat if the numbers didn’t add up?

But once I realized that errors are inevitable, I also began to realize that small modifications were allowed, and even expected. It’s a point emphasized by Pete and Mike Stevenson in their introductory remarks about the boat building process:

“One thing we always tell beginner builders (that veterans learn the hard way) is that when you’re working from raw materials, things just don’t automatically fall together. Small variations sometimes add up on you rather than canceling each other out, and farther along in construction it’s getter to recheck the dimensions on the actual boat against those in the plans, sizing the later parts to the parts already assembled rather than just following the dimensions in the plans.”

In other words, accept discrepancies and work with what you have. Above all, don’t panic. “It’s almost impossible to keep small variances in size out of your lofting and cutting,” they wrote. “In the long run we have to ear in mind that the water usually doesn’t care or even know about small variations, and you’ll soon forget all those nagging little discrepancies once the boat is shooting through the waves.”

It’s a message I read before I began, but didn’t appreciate for fully believe until I actually started assembling the parts.

Lofting pattern for the deck boards. The centerline is drawn along the full length of the four by eight foot plywood board (indicated by the shaded rectangle) and onto the garage floor. A scrap piece of plywood, is used for the rear portion of the decking.

Lofting pattern for the deck boards. The centerline is drawn along the full length of the four by eight foot plywood board (indicated by the shaded rectangle) and onto the garage floor. A scrap piece of plywood, is used for the rear portion of the decking.

Am I doing this right? Plywood boards ready for lofting. The one by eight pine board marks the centerline.

Am I doing this right? Plywood boards ready for lofting. The one by eight pine board marks the centerline.

Checking the lofted curves with a batten.

Checking the lofted curves with a batten.

It was a liberating realization and allowed me to sleep better at night. But my new philosophy was quickly tested when I started to loft the boat’s deck. After lofting the bottom boards, I was familiar with the general procedure, but this was considerably more complicated. Although the deck is a relatively small part of the boat—a narrow strip around the bow and along the port and starboard sides—the lofting is more complex and there is more room for error.

The first step is to loft the port side, which is made from two sheets of plywood–a full three-eights inch sheet forward and a piece of half inch board left over from cutting the bottom. The problem is that the centerline is drawn on a diagonal across the first board, but also must extend another six feet or so onto the floor of the garage so that the perpendicular station lines can then be drawn on to the scrap half-inch board.

The instructions were uncharacteristically vague about how this should be accomplished but I solved the problem by using a sixteen-foot board to draw the centerline and I then kept the board in place so that I could then use it as a straight edge to draw the station lines with a large t-square. The resulting assemblage of plywood and boards, all positioned at odd angles, combined with magic marker lines on the garage floor, looked alarmingly chaotic.

If I had been required to figure all this out three months ago when I triple-checked measurements and made my first timid cuts, I probably would have given up the project, right then and there. But I did the best I could to make the measurements precise and while I knew that my station lines were not exactly perpendicular, I refused to worry. Once the offsets were marked and nails were driven, I was pleased to see that my batten revealed a reasonably smooth curve. I readjusted a couple of nails by small fractions of an inch to eliminate a couple of wobbles and then confidently drew the lines.

Once cut, I will then flip the port side pieces and use them as a template for cutting the starboard side. All four pieces will then be glued to create a single fourteen-foot long deck in the shape of a giant “V.” The success of my efforts won’t be clear until I finally attach the deck to the stem and bottom with an assortment of gussets, bulkheads and the transom. But I’m going to assume that I did everything right and I am not going to worry. Well, not much,anyway.


Gluing Up–And Getting a Lesson in Humility

April 19, 2009
    The full keel after gluing. Admire the attractive lines, but try to ignore the worrisome gaps in the laminated keel boards.

The full keel after gluing. Admire the attractive lines, but try to ignore the worrisome gaps in the laminated keel boards.

As the crew of the Cimba arrives in the South Seas (after an uneventful nineteen-day passage from the Galapagos Islands), the temperature in eastern Pennsylvania finally warms up. The forecast predicts two days in the low 70’s. This is the minimum temperature needed to use plastic resin glue, which means I can get back to work.

The day starts cold, so I fill time by rereading the instructions about gluing and watching the instructional DVD that came with my plans. The video shows Pete Stevenson (the boat’s designer) and associates cheerfully scooping the dry glue powder into a can and casually pouring in some water and stirring. The consistency should be like “pancake batter,” they say, as the ingredients are combined with easy insouciance. The keel parts are brushed with the glue, slapped together like a sandwich, and quickly nailed together. In the DVD, this takes about five minutes.

It looks easy. It even looks fun.

I watch the thermometer and by early afternoon the temperature has risen to the upper sixties—not quite warm enough, but everything is ready and I am unwilling to cancel my plans. A couple of degree can’t hurt, right?

I confidently scoop some of the powder into a jar and begin adding water. I’m looking for pancake batter, but suddenly I realize just how subjective this consistency really is. Bisquick batter? Buttermilk pancake batter? Or homemade oatmeal pancake batter (my personal favorite)? Each has a different consistency. One is thick and sticky; the other is thin and almost watery. I add more water, then sprinkle in some more powder, trying to find a happy medium.

The final product might be a bit thick, but it’s still thinner than woodworking glue, so I decide it’s good enough. Next, I imitate the video and dip a cheap bristle brush into the goo and begin spreading it—thinly but not too thinly—on all four parts of the keel and stem. It’s sticky, kind of sloppy, and takes longer than I expected. I keep worrying that the glue will start to dry before I am finished, so I pick up the pace and slap the brush with effort, back and forth.

Finally, all the parts are covered and I quickly flip the top half on top of the bottom half and slide the pieces together, trying to line up the edges along all fourteen feet. This, too, takes time.

The next step is to secure the pieces with screws, one every four inches along both the top and bottom edges—more than 100 screws altogether. Still worrying about the glue setting, I work like a madman. I first use a countersink to predrill the holes, moving down the board with reckless speed– zing-zing-zing, over and over again. Now I replace the countersink bit with a phillips head screw bit, grab the bag of stainless steel screws I ordered online several weeks earlier, and drive all the screws within a matter a minutes.

The stem and part of the keel showing screws.

The stem and part of the keel showing screws.

I step back, ready to admire my work and relax, but instead I immediately notice several thin gaps along the top edge of the keel where the boards did not quite come together despite the screws. They aren’t wide, but I know they shouldn’t be there. Gaps let water seep in between the laminations and then…Well, I didn’t know what would happen, exactly. But it couldn’t be good. So I quickly grab my complete supply of clamps and tighten them around the widest gaps. This helps, but I run out of clamps before I run out of gaps, so I simply have to give up.

By now it’s late afternoon and the temperature, which never really hit an honest 70 degrees, is starting to drop and despite my overwrought concerns about premature setting it’s clear that the glue won’t be fully dry for a long time. Confronting this new crisis, I quickly make a tent over the keel with sawhorses, boards and several large tarps. I position a space heater inside and turn it on. Within a few minutes, it feels nice a warm inside the makeshift shelter and I congratulate myself for being able to solve one problem.

Still, I left the garage feeling that I still did everything wrong. I should have carefully measured the glue instead of following the “pancake batter” formula. I should have taken more time painting the glue; perhaps the gaps came from an unnecessarily thick application. Finally, I probably should have been more patient and waited for a warmer day when I wouldn’t have the added worry about glue setting–or not setting, as turned out to be the case.

The next morning dawned bright and warm. I pulled away the tarps, turned off the heater and inspected my work. The glue is dry and firm, but the gaps remain. I wonder if my mistakes—whatever they might have been–will have repercussions for years to come. This thought depresses me for a while, but I spend the rest of the day giving myself a pep talk. “This is your first boat, Paul. You knew this was going to be a learning experience. And, besides, you’ll still be able to get on the water and head down the Chesapeake Bay.” This helps. I have now moved past anger and self-recrimination and have achieved acceptance.

In Which I Learn to Loft

April 6, 2009
Keel, stem and bottom parts.

Keel, stem and bottom parts.

I would like to emulate Captain Joshua Slocum, who followed the tradition of ancient boat builders when he set about rebuilding Spray before his solo journey around the world in 1899. “My ax felled a stout oak-tree near by for a keel,” he wrote in the opening pages of his narrative, “and Farmer Howard, for a small sum of money, hauled in this and enough timbers for the frame of the new vessel.” But I don’t have a woodlot, or a farmer Howard, so my ax fell to the lumberyard and, for a $35 delivery charge, several sixteen foot long 1 x 12 boards were delivered the next day. In my more humble craft, the keel is not cut from a single piece of timber, as is tradition. Instead, it is assembled from four pieces of number two pine, laminated together with screws and glue to create a single 1 ½ inch thick keel. The illustration from the Pocket Cruiser’s plans illustrates the general principal.

Still, the work seems challenging enough. Indeed, I am about to get my first true lesson in the arcane art of boat building.

In carpentry, most lines are straight and measurements are easy. Tape measures and T-squares assure complete accuracy. The only degree that matters is 90 degrees. In boat building, however, nothing—absolutely nothing—is straight or 90 degrees. Every line is curved or angled. As I examined the plans for the keel, I began to fully appreciate this fundamental difference. The boat’s spine is like a snake that just ate a mouse; it not only follows a gentle curve, but also grows wider in the middle before narrowing again at the stem. Somehow, I have to accurately draw all of these curving lines onto my pine boards.

There are two ways to do this. The easy way employed by some boat designers is to print full size plans. Builders simply trace the pattern onto the boards, like a seamstress tracing a pattern for a shirt or dress on fabric. The traditional (and harder way) employs a skill unique to boat builders called “lofting.” Unfortunately, my project takes that harder way. It sends shivers of anxiety down my spine.

Like so many arcane nautical terms, “lofting” has an aura of Old World complexity. I was familiar with the term and vaguely understood that it was a necessary first step in the boat building process. But I viewed lofting as an art, something handed down from master to apprentice, a secret held by those within the guild. I don’t know where I got this idea. Maybe it was my insecurity as a boat builder; maybe I was responding to an attitude among a certain class of boat builders who do, in fact, try to shroud their work with an aura of magic and mystery. In either case, it was an enormous psychological barrier.

But it only took a few minutes of examination to realize that lofting the Pocket Cruiser is, in fact, a simple and straightforward process. “Lofting” simply means copying a pattern onto the wood. It takes time, but it’s not hard and, I discovered, it’s possible to do with a fair amount of precision.

The first step is to draw a centerline down the length of the wood. Next, a simple grid is created by drawing a series of evenly spaced lines perpendicular to the centerline. These are called “station lines.” To copy the keel’s shape onto the board, I simply drive two nails in each station line, one above and one below the centerline. These measurements are called “offsets.” The Pocket Cruiser’s plans tell me exactly how far above and below the centerline each offset is located.

For example, the first station line requires a nail 4 inches above and 5 inches below the centerline. This means that, at that station line, the keel in 9 inches wide. At the second station line, I place a nail 3 inches above and 5 ½ inches below the station line. This simple process is repeated along 14 station lines, each spaced 12 inches apart.

Here’s the fun part. After all nails are driven, I take a long, thin piece of wood—a batten—and push it against the line of nails. Instantly, the keel’s gentle inward curve is revealed as the batten pushes against each protruding nail. I look for mistakes in my measurements, which would be indicated by a bump or divot, but it looks pretty good. So with help from Matthew, my youngest son, I take a pencil and trace both the top and bottom curves of the keel. It’s like connect the dots, and just as fun.

Following the same process, I loft the boat’s stem from a shorter piece of wood. This will project upward at the boat’s bow.

Nails mark offsets in the stem (bottom left) and the keel (top right)

Nails mark offsets in the stem (bottom left) and the keel (top right)

These two pieces produce half of the keel. To create the full 1 ½ inch thick keel, I need to cut another keel bottom and stem. Now that I have a template, I don’t need to repeat the lofting process. I simply lay the pieces on top of pine boards and trace the pattern. The only variation is that the second keel half is cut a bit shorter in the front and the stem is cut a bit longer. This allows boards to overlap, creating a surface for gluing and fastening all four pieces.

The final step is cutting. I set my circular saw blade a fraction of an inch deeper that the boards I am cutting. Next, I lay the boards on pieces of scrap 2 x4 and, working with great care, slowly follow the curving lines of the keel. It’s a new experience purposely cutting curves with a circular saw; as a carptenter, I’m usually trying to keep my cuts straight. But I discover that it’s possible to cut gentle arcs without binding the blade if I move slowly. In short order, I have all four parts of the keel laying on the garage floor.