Go Get Your Blank: Build Thread

Go get a blank from Greenlight Surf Supply, round up some hand tools, and if you're so inclined, follow along. Feel free to ask questions.

I need to replace my 10-year-old log, so I started with a 9'3 Yater blank in polyurethane, from US Blanks. With a wood tailblock, It should yield a 9'3 classic longboard, designed for glide, smooth turns, and noserides small, clean or weak beachbreak surf. Here's some info on the blank: http://usblanks.com/catalog/longboards/93y/

Outline drawn with a spin template I designed many years ago for longboards in the 9'2 range.

 

Outline cut... ready for rockering and foiling.

 

Squared up the outline with a block, and checked symmetry. Once everything's symmetrical and true, I skinned the deck and got the deck rocker right. Once the deck rocker is set, I flip it over, foil the thickness to where I want it, then rough in the bottom contours. Here, the deck rocker has been planed, blocked to 100 grit, and the stringers taken down with the finger plane. Note: the blank comes with a singe stinger. I put in a thicker center stringer, and added two thinner stringers offset 6". This will help the blank keep it's rocker better as I foil it, particularly in the tail where I go fairly thin. It also adds snap resistance... and looks classic.

 

I only have time to work on it in the garage after work... so it's gonna be a slow process!

 

Here's a couple of pics of my ghetto garage "shaping bay." Just 9'x12' .5mil plastic hung with masking tape on both sides. I'll sweep up, then vacuum, then blow everything out with the leaf blower before I pull the plastic down, and I'll do that when I switch over to "glassing bay." The floor is covered in red rosin paper.

 

Foiled and rockered the whole board, and roughed out the tail and mid section bottom contours.

Rocker: Entry rocker is "natural" (what came in the blank) and the tail rocker has added kick for noseriding. So the front third and middle third are "continuous," with the tail third "staged"... a two-stage rocker, by definition.

Bottom contours: Tail third has a heavily rolled vee that fades in about 36" from the tail block, and accelerates the rail rocker all the way through the tail. Midsection third is flat.

 

While the rocker in the tail, and the bottom design in the tail, is to facilitate smooth turns and the ability to trim from the nose, in the front third, I'm adding a teardrop shaped nose concave. It will be a blended concave to create a flatter planing surface under the nose for better noseriding. There's a couple ways to do that... you can trace the nose with a block and some rosin paper, then cut out an oval or teardrop template for your concave...

 

Or you can freehand some 1/4" tape on one side, then transpose that curve to the other side for symmetry:



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When considering nose concave outline and depth profile, think about how water enters under the nose, contacts and interacts with the bottom of the bort, and flows out of the concave and along the bottom and rail. Do the same thing when you consider rail foil and shape... what you do to the shape of the rail, or concave(s), or vees... in the forward parts of the board have everything to do with how the rest of the board directs the flow of water.

In other words, if water is allowed to enter under the nose freely along the stringer, it will tend to follow that line down the center of the board until it comes into contact with another bottom feature... concave, belly, vee, etc. But also keep in mind that the bottom of the board is not flat in the water... it's always contacting the water at an angle relative to the slope of the wave face. So the inside rail... from the nose to around where the wide point of the outline of the board is, is interacting differently with the outside rail... almost always pushing water outward and backward, toward the outside rail and tail. This means the back half of the concave is doing most of the lifting when on the nose, with the inside edge providing more lift than the outside edge. This is why the inside foot on the rider is always weighted slightly more than the outside foot when hanging toes. If you were riding a pointbreak, and only going one way... ever... you might be able to design your nose concave asymmetrically to accommodate this imbalance of force. But that's not practical in beachbreaks... so nose concaves should always be symmetrical.

If you look closely at my nose concave outline, you'll see a slightly flattened part of the curve near the aft tip of the teardrop. That's there to create a lift/drag point along the center of the board for balance, and added fulcrum of lift.

 

Did the nose concave and turned the rails today. Glued up the wood tail block. I'll rough shape the tail block, glue it on with some hot resin, then finish shape the whole thing at once, block and all.

I start my nose concave with the planer by cutting a couple of passes down the stringer to get the depth to fade in and out like I want it. Then I rough it out with the surform, then go to a soft block with 80, 100, then 220 to get the scratches out. I do the stringers with a finger plane and a mini spokeshave.