My surfboard is what you might call (what my friends do call) a pig-board. I shaped it myself, and wrapped it with two layers of 4-ounce fiberglass, teh first layer, clear, for lightness. The second layer, dung orange, to cover all the flaws in the first layer.
Value judgments aside, my board is of a type commonly known as a "fish," as in goldfish. It has flat sides and the wide double tail of the paper fish seen floating in the air on Chinese holidays. Unlike my friends' surfboards, which taper like muscle to a tail sharp enough to lift cuticle off your fingernail, my board is wafer shaped and slightly dumb.
At six feet, it is emphatically on the short side, and in large surf I often feel like a loady falling downstairs.
But I am determined to ride the board, and boards of my own making, from now. I decided to shape my own as an exercise in practical physics. As a bonus, I found I could build my own surfboard for less than $40 (shortly after I found I couldn't get up $150 for a new one).
I saw the blank I needed at Mitch's Surf Shop in La Jolla. Mitch has a shop mostly full of surfboard blanks, with some room left over to store bolts of fiberglass cloth, gallon tins of resin and skateboard wheels. I wanted to do a short board without too many complicated curves. Mitch showed me two six-foot "seconds" which he sold for six dollars apiece. Seconds aren't as good as first, but they aren't rejects and, as Mitch said, "for that price you can afford to screw one up and start over."
Mitch had my number.
Surfboard shaping is a delicate and methodical art. It proceeds in stages calculated to keep the various aspects of the developing surfboard in proper relationship to each other. Shapers over the years have refined special tools for each step of the job, usually the lightest tool the job will bear. However, as Mitch suggested, I would need more than a block plane and a lot of sandpaper.
So, equipped with a Surefoam tool, hand plane, saw, and a good sunny morning, I began my first surfboard. I stacked up a few cinder blocks on the back porch, put towels over them and laid my first blank on top. A polyurethane foam surfboard blank is blown to roughly the shape of a surfboard, then halved from nose to tail and glued to a half-inch redwood, balsa, or cedar stringer down the center for strength. Portions of this stringer stick out all over the rough blank, so first I took the excess wood down to the level of the foam with the hand plane.
Still using the plane, I smoothed out the foam on the top and bottom of the board. When I had cleared all the flats, I got out my template, the pattern drawn from a friend's board onto butcher paper, and drew the outline onto my blank. I cut the shape out with a handsaw.
Now I had the basic outline of the board and fresh white foam surfaces to work with. The problem was to turn the corners into curves and blend them into each other in an agreeable way.
I began by working on the rail, or outside edge of the board, blending the center thickness down toward the bottom line in a gradually accelerating curve. I did this by making a series of deeper and deeper bevel cuts along the rail with the plane, always leaving some flat surface at the edge to work with later. After I did a little work on one side of the board, I matched it on the other.
The work seemed to be going well, the shape of a board began to appear. But as I tried to shape the rail into the rocker, or bottom curve of the board, I noticed some problems with symmetry. As the sun got higher in the sky and the shadows on the blank moved around, one side of the blank began to look distinctly thicker than the
other. I rounded up a set of large calipers, measured and, sure enough, one side was way too thin. I realized that I couldn't even up the thickness without shaping a twist in.
I set that blank in the closet and roughed out the second one. This time I used the calipers to measure everything, and turned the board so that an approximately equal amount of sunlight fell on each rail. I shaped the rocker first, and the rail down into it. By late afternoon, I had a fine-looking surfboard blank developing, with a good flat bottom, curved deck, and about a half inch of flat foam still showing around the edge. At this flat I would do the critical rail shaping.
The shape of the rail determines the flow of water off the planing surface. It creates the trim and turning characteristics of a surfboard. A rounded rail touches more of the wave (surface tension) and releases more easily. A sharp, or "hard" rail exposes less turning surface to the wave, requires more punch to turn and gives stability at speed.
Short boards are inherently unstable. To compensate, I wanted a hard rail which would slip less. I wanted a flat rocker for drive and stability. Less rocker is less turnability too, but on a six-foot board that's no problem. On a nine-footer you want a lot of rocker or the board just won't turn.
I had it all worked out when I approached the board next morning. I already had the rocker line I wanted from yesterday's session. I shaped the rail line down into the bottom line using the Sureform, gradually working the flat edge to less than an eighth of an inch. Then I flipped the board over on its top and worked that final bit of flat up from the bottom until I had a nicely foiled shape resembling (I thought) the leading wing of a sexy executive jet.