Build a Surfboard Episode 1: Shaping

Learn to shape a surfboard from the famous Johhny "V" Voxlund in Haiku Maui.

Other episodes of this project:
Build A Surfboard Episode 2: Sanding and
Episode 3: Laminating and Vacuum Bagging

Johnny starts with a urethane foam "blank" he gets at a local supplier "Fiberglass Hawaii".
The blank is made by "US Blanks". He asked for the 9'5" blank with the maximum "rocker".
Rocker is the curve of the bottom that makes a board look like a banana from the side.

The workbench or "rack" supporting the board in this photo is padded with carpet scraps. It allows him to support the board on its edge or flat like a table while shaping. The fluorescent sidelights lining the room at elbow height let him see the smallest irregularity or bump on the board's bottom.

Johnny shaped surfboards and windsurfing boards fulltime for many years and has worked as "shadow shaper" for other famous shapers. Now he only makes a few boards a year. He charges a couple of thousand dollars for a board. He specializes in high end custom boards for discerning amateur surfers. He says "people pretty often think they're bad surfers. Usually it's the board that's bad. There's been a revolution in board design in the past few years."

Words music and photos by Star & Tim.

Step 1: Blanks

A "blank" is a block of foam shaped like a surfboard. Usually a blank contains one or more "stringers" which are lengthwise strips of wood that give the middle of the board extra strength.

Here's Fiberglass Hawaii's stock of blanks at their store in Kahului Maui.
These are mostly made by "US Blanks", which is a new company.
Until a few years ago a company "Clark Foam" made 90% of the blanks in the world. They molded a huge variety of blanks so you could order one very close to any shape you wanted. The molds are made of two large pieces of concrete with a hollow cavity between. Two-part urethane is mixed and poured into the mold which is clamped shut. The urethane expands and puts huge pressure on the mold. The amount of urethane put into the mold determines the density of the blank. The concrete mold prevents it from expanding too much and being soft. After the blank is taken out of the mold, it's sawed down the middle and a thin wooden "stringer" is glued in place.

In 2005 "Grubby" Clark, the founder of Clark Foam unexpectedly closed his business and smashed his hundreds of molds with an earth-moving machine. That caused a shortage of blanks in the industry. Many shapers couldn't make boards. Some shapers started experimenting with styrofoam and natural materials for their surfboards. Several new urethane blank manufacturers have started up, but it's still not possible to get the range of blanks Clark used to carry.

Johnny now has to order a much larger blank and cut off a lot more foam than he used to.
Many shapers use computer-controlled milling machines to make their boards. They don't care how thick the blank is to start out. A rectangular block would be fine for them.

Step 2: The Factory

Here's the high tech facility where the magic happens. It's a corrugated shed in a big nursery garden.
The shed is surrounded by flowering and fruiting plants. He likes the rustic atmosphere so he does as little as possible to change the building. The roof leaks so he's put up plastic under the roof. He attached it with screws through beer bottlecaps clamping onto pieces of tape on the plastic. There's "tack paper" on the floor to capture any loose dust but now it's just a floor, the tackiness was used up long ago.

Step 3: The Planer

You're going to see a lot of this tool. It's a Skil model 100 planer. Good thing they last forever, because it's no longer made. All the shapers love it. There's a lever at the front that changes the depth of cut. When shaping a board you move this lever with each cut. Each cut starts and ends at zero depth so there's no step or divot at the end of each cut. Each cut is just smoothly blended with the rest of the bottom contour. All the other planers have a knob that you twist to adjust the depth of cut. That is a lot more work for your wrist and it's a lot harder to get graceful cuts.

He used to use this old hand plane to work on the stringer. Then he got the little aluminum one that uses a razor.

Johnny replaced his Skil 100 planer's blades with the nubbly grinding drum seen here.
The planer blades had the following problems that this device solves:
They left ripply marks in the foam.
They could grab and tear out chunks of foam.
When planing across the stringer the blades could grab and splinter it.
The blades cut big flakes instead of the dust this device produces. The flakes from two boards filled up his shopvac. With the grinder drum he can do five boards before emptying the shopvac.

Which brings us to the next part of the system, Dust Collection

Step 4: Dust Collection

If you just let the shavings spew out of your planer you'll create a really amazing mess.
You can see it done that way in the movie "Endless Summer 2".
It looks like a snowstorm but worse. The dust has a static charge and sticks to everything. It'll make you look like a snowman. It's really hard to sweep up. Later when you're trying to get a nice gloss finish the particles of dust will jump onto your wet finish and cover your board with tiny spikes.

The right way is to use a dust collection system. The Skil 100 ejects shavings upward. That lets you attach a collection hose to the middle of the tool where it won't get in the way or make it lean to one side.
Jonny uses a very flexible type of clothes dryer hose for that. He laments that this type of hose is no longer made. The hose is suspended from the ceiling right over the board. It plugs into the regular hose that came with the shopvac. The shopvac hose isn't quite strong enough and can collapse in one spot. He wrapped it with wire there to keep it open. The shopvac is an extra-quiet model.

Step 5: Plan and Draw the Outline

Start by drawing the outline or top view of the board on your blank.
Using the wooden stringer as the centerline of the board, Johnny draws horizontal lines at the following places and then measures and draws lines to mark the width there:

Tip
Tail
Midpoint
Point of maximum width - on this board it's 6 inches forward of the midpoint of the board.
1 foot back from the tip
1 foot forward of the tail.

Then he draws smooth curves to connect these points. He's got a quiver of masonite templates from previous boards that help him draw curves he likes. One side of the template is a nose curve, the other side is the tail curve. He flips the template over to draw the four quadrants of the board.

Shaping jargon takes a while to get used to, but it's necessary to understand what makes one surfboard different and better than another. The following phrases will be explained later in the text of this project.
His current shaping philosophy calls for a lot of rocker. He makes "longboards" that are suitable for waves of any shape or size. His boards are faster in turns than they are going straight, which makes them "squirt" and gives them "drive". The rocker prevents them from "pearl diving" or "pearling", so the rider can put their weight very far forward on the board, which also improves "drive".

This board will have "reverse vee" style "concave" in the nose and middle section, a flat spot about the size of two hands right at the tail, and "tucked rails".

For reference, Maui terminology for the different sizes/styles of surfboard are:
Type Size
Performance Board up to 6'8" or 7'2"
Egg 7' to 8'
Mini Tank 8'-9'
Longboard 9' and up

Step 6: Outline Is Marked

Here's the tail of the board, which is the business end as far as the bottom contour is concerned. It's always in the water and always working. The important measurement here is the "foot mark" which is the cross line one foot from the tail of the board.

The "table" under the blank is actually a stand-up paddleboard johnny is just finishing. That board has a lightweight styrofoam core with high density skins made of "coremat" to make it ding-proof. The matting pattern seen here is a sheet of woven bamboo laminated under the fiberglass skin. The deck is done the same way and it looks really nice.

Step 7: Saw the Outline

Johnny uses a big Japanese "pullsaw" to cut out around the outline he's drawn. The pullsaw has a very sharp thin blade that cuts quickly. He cuts just outside the lines.

Until a few years ago a company "Clark Foam" made 90% of the blanks in the world. They molded a huge variety of blanks so you could order one very close to any shape you wanted. The molds are made of two large pieces of concrete with a hollow cavity between. Two-part urethane is mixed and poured into the mold which is clamped shut. The urethane expands and puts huge pressure on the mold. The amount of urethane put into the mold determines the density of the blank. The concrete mold prevents it from expanding too much and being soft. After the blank is taken out of the mold, it's sawed down the middle and a thin wooden "stringer" is glued in place.

In 2005 "Grubby" Clark, the founder of Clark Foam unexpectedly closed his business and smashed his hundreds of molds with an earth-moving machine. That caused a shortage of blanks in the industry. Many shapers couldn't make boards. Some shapers started experimenting with styrofoam and natural materials for their surfboards. Several new urethane blank manufacturers have started up, but it's still not possible to get the range of blanks Clark used to carry.

Johnny now has to order a much larger blank and cut off a lot more foam than he used to.
Many shapers use computer-controlled milling machines to make their boards. They don't care how thick the blank is to start out. A rectangular block would be fine for them.

Step 8: Shape the Rocker

Johnny likes a lot of rocker. He says "Rocker lets you put your weigh forward on the board. It makes the board faster. You can't have enough rocker. Until you have too much. Too much makes the board slow."
Here's a masonite rocker template he made for a previous board. For the current board he shapes the rocker by eyeball.

There are fluorescent "sidelights" along each side of the room at elbow height. This light hits the board at a low angle and lets him see any bump or irregularity in the board.

That means planing a lot of material off the ends of the board to increase the rocker.
He checks the board for flatness and twist by raising and lowering on end while sighting down the bottom.
Another method is to put two levels across the board at two different points and sighting across them to see if they're canted.

Step 9: "Skin" the Bottom

After shaping the rocker there's still untouched blank in the middle of the board. The foam that was in contact with the mold has a yellowish skin of higher density urethane with traces of mold release on it. That needs to come off. To take that off without messing up the nice curve he put so much work into, Johnny planes 1/8" of the whole surface of the board. He rests the front of the planer on unplaned surface for the whole stroke. That reference surface makes the operation quick and easy. You can hear the sound get louder as the blade hits the higher density skin foam or the wooden stringer.

Speaking of loudness, Johnny wears a pair of "Peltor Worktunes" hearing protector headphones with a built-in radio while he works.

Step 10: Shape the Bottom Concave

Johnny cuts down the middle of the board to give it "concave". Here he checks the initial cuts that define the maximum depth. He wants it to be 1/4" deep. Then he planes the rest of the concave. He prefers the "Reverse Vee" style of concave with flat sides instead of the more common rounded concave.
He says "The vee gives you less of a hook here at the rails, and makes the rails less grabby."
He carves another reverse vee concave in the front of the board. The concaves blend into areas with no concave at the tail and in at the front of the board, about 1/4 of the way from the tip.

Step 11: Block Sand the Outline

Use a block of wood with a piece of 50 grit sandpaper wrapped around it to sand the edges of your blank smooth. There are some scratches in the blank from sawing it.
To sand them out Johnny says "Sand everything AROUND the scratches. The scratches make that foam low-density, and it comes off real easy, so if you sand there, you'll get a big divot. Put the pressure everywhere else. The foam with no scratches is solid. You need to lower it to the same height as the scratch, to get the whole thing to come down together."
Check the width of the board at the foot marks and the middle to make sure it's symmetrical.

So far the deck of the board hasn't been touched. You can see the yellowish skin on the front half of the board. Sunlight makes it turn yellow and then brown. In the background there's an old Clark blank that's turned brown.

Step 12: The Rails

The "rails" are the edges of the board. They determine how the board grips the wave and how much the water wants to stick to the board or release cleanly. A "hard rail" has a sharp square edge at the bottom. The flow releases cleanly, but the board doesn't stick to the wave enough. A "soft rail" is one that's round, with no corner at the bottom. The board sticks to the wave well, but the flow gets sucked around it, making the board slow. This board will have a "tucked rail". That's an overhanging rounded rail with a sharp edge underneath.

Shaping starts by cutting bevels.
There are two bevels, the top one, which fades into the "crown", or flat part on the deck, and the bottom bevel, which should be a 45 degree bevel. The bevels are cut before the nose is taken down, so they run the whole length of the board. The flat part, remaining from the edge of the blank is called the template band and continues to exist as a reference for the rest of the edge shaping.

He says: "Make your bottom bevel 1/2" wide. I'm making this one 3/4" wide because I know how to make it work. You shouldn't go over 1/2".

The first photo shows the bottom bevel. The next shows the crown bevel.

Step 13: Placement of the Maximums

Johnny says: "They used to put the thickest part of the board up here in the front. You know, where your chest goes when you're paddling out. But then when you're trying to catch the wave the board points up in the air instead of down the wave. So then you don't catch the wave and you think you're a bad surfer. No, you've just got a bad board. And then you go home without catching any waves and you think surfing is hard."

His hands give a surfing demonstration. "You're up here trying to catch this wave, and you need to point down the wave with this penetration angle, or else you've got to paddle like a superman to go fast enough."

He measures the board with a big caliper. "You've got to get one of these or make one to measure boards. Yep, here it is, the maximum thickness is 1" behind the center." He's doing this for us. He was using his hand for a caliper when we asked him a question.

For this board, the maximum width is 6" ahead of center, the maximum thickness is 1" behind center, and the maximum thickness of the rails is a few inches behind that. He says this aft placement of maximum rail thickness helps the board "rail over" in turns.

Step 14: Asymmetry in the Blank!

Johnny planes the skin off the deck. He stops with some skin left on the right side. "The blank isn't symmetrical. This is the first time I've used this blank. See how this side just isn't as thick? That's one of the things you have to deal with. So I'll make it work."

Step 15: Thin Out the Nose & Tail

At this point the nose and tail are still quite thick. Thin them out by running the planer across the board at the tip and tail. These are deep hogging cuts that remove a lot of material. Shave down the stringer by running the edge of the cutting drum along it. If you have blades in your shaper go very slow when you hit the stringer so you don't splinter it.
Johnny lightens the nose and tail as much as possible to make the board responsive.
The deck at the tail of the board has a slight upward turn like the kicktail of a skateboard.
He fairs the tip and tail curves in with the rest of the deck curve with lengthwise strokes of the planer. He says "That's marketing. You have to do that. People are always sighting down the deck of the board like this. Look at this. Doesn't it look great?" He laughs. (the fairness of the deck curves makes no difference in how the board surfs.)

It does indeed look great. It looks like it's surfing already.
The board is now fully shaped, which concludes the Shaping phase.
The next phase of building the board is Sanding.