Please make sure if you are planning to shape a single concave in the bottom to account for that removal of foam in this step. Surfboard thickness is measured around the midpoint of the blank with calipers and the concave affects that thickness measurement. If you're putting in a 1/8" deep concave later in the shaping process, make sure your blank ends up around 1/4" thicker at the end of this process. You'll remove that 1/8" of foam while shaping the concave in the bottom and another 1/8" when blending the rails into the deck and fine tuning your shape.
Start on the stringer with the trim plane. Since wood shapes differently than foam, it's easiest to shape the stringer down first and then shape the foam down to the stringer with a 24" Rasputin Rasp Tool. The stringer will act as a hard stop and you'll know the curve is smooth and even from rail to rail.
Run the trim plane along the stringer and dig the blade into the wood. There should be a nice thin wood curl roll out of the trim plane. Usually you'll come across a change in direction of the wood grain somewhere along the stinger. You'll know it when the blade digs in and you can't plane any more. Simply go in the opposite direction now.
Check your progress by measuring the thickness of the stringer with the calipers or put a straight edge (bubble level) across the board and measure down to see how much you've shaved off. Continue the process and stop when you get to your thickness goal (remember it's 1/8" - 1/4" thicker than you final board thickness).
Now take your 24" Rasputin Rasp Tool and scrub the foam using long strokes to shape the foam down to the stringer. Stand at the tail and pull the rasp toward you for the most efficient foam cutting, same for the nose. Stand on the side of the board to get the middle section down. When the foam is flush with the stringer from nose to tail you're done with the thickness adjustment.
HOW TO SHAPE A SURFBOARD ROCKER and FOIL
(Skip this step if you're shaping a custom close tolerance EPS Blank)
First, let's go back to tracing your outline template on the blank. Like we mentioned before, it's a good idea to push the template towards the nose or tail to get the rocker dimension really close to one of those rockers so there is less shaping. Normally you'll use the nose rocker in the blank and push the template to where the nose curve matches your desired nose rocker. Then you'll just shape in more tail rocker. Of course you can always do the opposite and use the blank's natural tail rocker curve and adjust the nose rocker. It's up to you and your design. You can use the rocker stick and method described below to find the rocker number and put a pencil mark on the stinger to line your template up with.
Now, with your nose and tail rocker measurements handy, your first task is to make some pencil marks on your blank to act as guide points to hit as you are shaping your rocker.
You will need a Tape Measure and a “Rocker Stick” to identify and mark the key points on the blank. A Rocker Stick is simply a long, straight stick placed along the stringer of the board to measure the nose and tail distances of the rocker from the lowest point of the bottom curve. Shapers typically use angle iron or square aluminum sticks that are cheap and easy to find at home centers but you can also use 1 x 4, 2 x 3, or 2 x 4 lumber. Find one that is at least as long as the board you plan to make. You can use any long stick to measure rocker, as long as it is straight and not too heavy so that it will bend the blank when placed on the stringer.
Place your rocker stick on the stringer and find the level point with a bubble level by sliding the rocker stick back and forth. You can now measure the distance between the bottom of the stick and the stringer at key points along the board. So if your rocker stick shows 1 1/2” of tail rocker and you want to have 2” of tail rocker in your board, you will be shaping more material off the tail of the blank than the middle, in order to increase your tail rocker to the desired 2”.
To keep the rocker curve nice and flowing we'll shape the stinger with the trim plane. Flat and square tools like a trim plane are good for trimming things flat but not making curves! So we approach making curves with what we call the "stair step method".
The stair step method goes like this: take the trim plane and we'll start approximately 3” away from the tail (or the nose if you're adjusting nose rocker) and we're going to cut the stringer down from that point all the way off the tail in one pass. Then we're going to “step up” toward the center of the blank about 6” inches from the tail and then we'll cut start cutting from there off the tail. Then we'll move back 9”, 12”, 15”, 18” however far you want to go up the blank depending on your design. Every time we use this method to cut the stringer all the way off the tail from multiple points stepping up toward the middle of the board we're going to create a nice smooth continuous curve for our rocker. You want to repeat this stair stepping cut method as many times as you need to to achieve your rocker to the point where you're marked on the end of the stringer.
Now we'll use the 24" Rasputin tool again just like we did to get the thickness down and just scrub the blank down to the stringer.
A final note on marking your blank: don’t get overly caught up in the numbers! Water flow doesn't care about numbers, only curves. It’s OK if the blank does not allow you to get your exact rocker and thickness profile. It is more important to have smooth, continuous curves in your rocker than to try to “manipulate” the blank into fitting your exact thickness and rocker numbers.
You can also use a power planer to foil your blank but it's not recommended for your first few boards as we discussed in the tool section of this building guide. If you want to use a power planer we recommend checking out our advanced Masterclass videos which show proper power planing techniques so you don't screw it up.
FOILING THE DECK
With your bottom rocker shaped and smoothed, the final step in foiling your blank is removing some foam from the deck. Foil is the distribution of foam from the nose to the tail. We want a relatively thin nose flowing gradually into the thickest part of the blank (under our chest and belly when paddling) and smoothly tapering to a thin tail.
This process is similar to foiling the bottom, but you should be really focusing on the tips of the nose and tail as you've already brought the blank down to thickness in the middle and have a natural foil from the blank's design.
Once your final thickness points are marked on the stringer of the nose and tail, you follow the same procedure as the bottom with the trim plane and 24" Rasputin Tool to remove material from the deck down to your desired thickness. However, you will find it is very difficult to effectively plane the stringer in the nose area of the deck because of the upward curve of the blank. In this area, simply rotate the trim plane about 45 degrees to the stringer and you'll be able to get the tool into the curve. You'll remove less wood at an angle like this but it'll get the job done.
At this stage in the game your blank should have a smooth, flat bottom with the correct rocker, smooth vertical rails, and a smooth, flat deck.
Basically, boxy rails have more volume and therefore more buoyancy/resistance when engaged into a wave face. Knifey rails have less volume and therefore penetrate the wave face easier. Knifey rails are used for higher performance shortboards where rail-penetration is desired, and boxy rails are used for longboards and less performance-oriented boards where flotation and stability are the desired characteristics.
MARKING RAIL BAND GUIDE POINTS
Use a tape measure to mark the appropriate rail band points on the rails for both deck rail bands and bottom tuck. Some people draw lines to connect these dots to create guidelines for a more visual approach to shaping. Up to you but scribing lines is not really necessary, just shape until you hit the dots laid out on the blank. As in many other steps of shaping, it is better to trust your eyes, step back from what you are doing, and try to get your rail bands cut as smoothly as possible by eye. The rail band marks on the deck and rails at a few key points along the length of the board should be enough to guide you through the process.
One final note on marking rail bands: For the most part, the vertical surface that remains along the outside of the rail once the tuck is shaped and primary band is cut, determines the overall volume of the rail. It is important that this “band,” which will become the rail apex once the rail is finish shaped, is widest at the widepoint, and tapers smoothly toward the nose and tail. This taper will determine the “foil” of the rail – how the volume of the rail flows from nose to tail.
SHAPING THE BOTTOM RAIL BAND
Most shapers begin with the smaller rail band on the bottom of the board. Besides old-school longboards, most boards have a sharp bottom edge running from the tail to about 16-20 inches up from the tail. This sharp edge then slowly tapers into a rounded bottom rail through the nose area. Some shapers shape the bottom rail band with a Greenlight's Rail Runner Tool for ease of accuracy. You can also use a planer, or by hand with a G-Rasp and then a hard sanding block.
To begin shaping your bottom band, place the blank bottom-up on your shaping racks with your shaping weight near the center of the board. Start shaving with the Rail Runner or shaping tool of your choice with light pressure where you want the hard edge to begin tapering, and work your toward the nose. Use the tool to remove most of the foam down to your bottom rail band marks, then smooth and clean up this band with your hard sanding block. When completed, this bottom band should get wider toward the center of the board, then taper slightly towards the nose of the board. Once again, as you’re shaping this band, step back and take a good look with your eye. This is another good time to utilize your sidelights or fluorescent handheld light. Ideally, the band has a nice smooth curve to it, with no sudden changes in width or angle.
SHAPING THE TOP RAIL BANDS
The top rail bands are substantially larger than the bottom. You can do them by hand with a G-rasp, or power planer. Just like with foiling your board, you can always adjust your planer to a low-depth to minimize potential mistakes while planing your rail bands. There are typically two main deck railbands that you cut before you begin smoothing and rounding the rails. The first cut is the steeper band which is closer to the rail on the deckside, the second band cuts further toward the stringer, but not as deep as the first rail band.
You need to be very careful with the planer as you approach the nose area, as you don’t want to take out a big chunk of nose by accident. It is safer just to plane your railbands with the planer up to about 10" or so away from the nose. You can finish the rail bands in the nose area by hand with a G-rasp and hard sanding block.
Since top rail bands reach their maximum depth toward the center of the board, you will also want to try to adjust the planer depth “on the fly,” keeping it lower in the tail and nose area, and higher in the center. Like everything else in shaping, the key is just to try to have nice, smooth bands with no sudden changes in width or angle. Once you remove the majority of material with the planer, finish off the first rail band with your hard sanding block, trying to have the band meet up with your first rail-band markings. It doesn’t have to be perfect, just try to have the band come out as smooth as possible.
Once the first rail band is cut and smoothed, you plane the second band, using the marks on the deck as your guideline, and intersecting the first rail band at about its mid point. Use the planer to remove most of the material for the second band (except in the nose area), and finish up with the hard sanding block. Use the sanding block to smooth out the second band and get it close to your second band marks on the deck. Don’t worry if you still have pencil/Sharpie marks all over your blank at this point. You will sand them out in the final sanding step.
At this stage you should have two distinct rail bands carved into your deck, and one on the bottom of your blank. Now you need to use your hard sanding block to “break down” the distinct lines connecting each rail band. Use your hard sanding block with medium grit (60-80) sandpaper to flatten the hard edge between the two top rail bands. You will create two new edges by doing this, but the angles on these new edges are lower and not as sharp. Blending the bands is the continuation of this process until you have a series of very small bands with low-angles, forming a rough curve which represents your final rail shape. The very top rail band should almost invisibly blend into the deck.
You also should continue to have your vertical rail, which represents the original outline of your board. Since you’ve carved out your rail bands, this vertical section is much smaller than it used to be. As you continue breaking down the rail bands with your sanding block, try to make sure you maintain that small vertical band down to about 1/2” width or so. If you sand into this band, you are changing your outline.
You must also blend your bottom rail band into the bottom of the board and the vertical band on the side of the rail. The process is the same as the top, albeit you will only need to take a few passes smoothing out the distinct lines on the bottom as it is a much smaller radius curve than the top. Try to leave a nice, smooth distinct line where your bottom rail curve meets the bottom of the board. This is done by making smooth, long strokes with your sanding block without changing the angle of the block as you are blending the underside rail band into the bottom of the blank. Remember to be careful toward the tail of the board, where you want to maintain that 90 degree sharp edge.
Once you have broken down all of your rail bands, it’s time to smooth the remaining small bands into a nice, round final rail shape. For this step, most shapers SandShark sanding screen, pulling the screen back and forth over the rails to smooth out the remaining bands into a nice clean curve. Take your time with the sanding screen and don’t pull/push too hard. The screen can remove a lot of material quickly if you are putting too much pressure on it. Start by screening the top side rail, then the bottom side rail. Finally, quickly smooth out the top and bottom at the same time by wrapping the entire rail with the screen to radius the entire rail smoothly. Remember to use a light touch here, as removing material from the former vertical band will change the outline of your board.
At this stage, you are in the home stretch of the shaping your board. All that is left to do is do a quick smoothing of the entire shape with a soft sanding pad and medium grit sandpaper (80 grit) or sanding screen. You can screen the board with progressive grits to tighten up the small voids or simple seal the board with sealing spackle at this point if shaping EPS foam (see below). Start with 100 grit and progress to 150 and 220 for a really smooth board that will look great under a tinted lamination.
When final sanding, use a surfboard shaping foam sanding pad and hold the sandpaper or screen under the pad by folding one corner of the pad up and grasping the screen with your fingers on one hand while the other hand presses down on the pad and screen to sand. Holding the leading edge of the pad up will stop the screen from rolling over and scratching your board. Keep the pressure light, as you don’t want to remove much foam at this stage. You just want to smooth everything out and get rid of any rough spots.
This is also a good time to sand away any pencil/Sharpie marks that are still on the blank. Just be sure to sand lightly to avoid making dents in the blank. Now is also a good time to check your stringer one more time and plane high spots flush to the foam with a spoke shave.
Sealing the Blank (Optional)
Sealing the EPS blank is optional but we recommend it to make your board look great while eliminating a lot of fine sanding and screening. This smoothes out any holes, provides a nice white surface for artwork, and seals up the pores of the blank so it doesn’t absorb too much resin when you are glassing. Our Engineered EPS doesn’t need to be sealed as it will not have as much bead tear out as other EPS foams, but if you want a clean looking white board, painting the blank, or tinting the resin, here’s how:
Use a bag of our EPS Surfboard Sealing Spackle (one bag will seal a board up to ~7'0" long). It is bright white and light, so is the preferred spackle for sealing EPS blanks. Scoop a hunk of spackle into a mixing cup, and add a little bit of bottled or distilled water (NOT TAP WATER - the minerals in tap water will turn the spackle yellow) to the mix to turn the spackle into a whipped cream consistency.
Pour this water/spackle mixture over your blank and spread it around smoothly and thinly over the surface of your blank with an epoxy spreader. Scrape off the excess spackle back into your mixing bucket, as you can re-use it for the other side of your board. If you have any small dings or chunks missing from the blank (common in the stringer area), you can fill these holes with the spackle.
The idea is to just fill the small voids in the foam and not put a thick later on the board. Scraping the spackle off with the epoxy spreader will take all the excess off and leave just what is needed in the holes.
You can apply the spackle to the rails with your hands and just glob it on since your hand can conform to the rail shape easily. Then follow with the epoxy spreader to clean it up.
Allow the spackle to dry, flip the blank over, and repeat the process on the other side. Just add a bit more water to your old spackle mix and it should be ready to go again. Once the spackle is dry, you can lightly sand the entire blank with a soft sanding pad and 220 grit sanding screen or sandpaper.
HOW TO INSTALL SURFBOARD FIN BOXES
If you choose to install FCS Fusion, FCS2, or Futures fin boxes now is the time... before fiberglassing. These three fin systems are called "pre-glass" and installation requires a trim router and install jig designed specifically for each fin system. You also have the choice to use FCS X-2 plugs or FACTORY plugs and install them after glassing the surfboard is done.
Fin installation starts with laying out where the fins will go before routing the pockets. Greenlight's G-square layout tools do the work for you to ensure proper fin alignment and toe in angles.
Click to download Greenlight's Surfboard Fin Position Layout Guide for tri-fin, quad, and 2+1 fin setups
Fin placement is always measured from the tip of the surfboard's tail and a certain distance "in from the rail" as shown in the fin placement guide.
There is a lot of detailed installation instructions for each fin system and how to videos on the product page links below:
*Glass-on fins are attached to the surfboard after the fiberglass lamination is complete, but before the hotcoat.
Download Greenlight's Glass-on Fin Cant template here
Before you glass your board, you have the option of preparing a few cosmetic touches to your blank. This is the stage where you would airbrush or paint the foam blank and it is also the stage you would design and print any logos that you want to laminate under the fiberglass.
AIRBRUSHING OR SPRAY PAINTING THE BLANK
We are not going to give detailed advice on airbrushing or painting your blank, since it is primarily a creative process. However, there are a few things you need to know if you are going to airbrush or paint your blank. For airbrushing, you should use water-based tempera surfboard paint. You will also need an airbrush and compressor. If you plan on spray-painting your blank with a rattle-can, you must also use water-based spray-paint, especially on EPS blanks. Regular spray-paint contains styrene, which will literally melt your EPS blank. Water-based poster paint has proven to be the best for surfboards for durability and to ensure a good bond between the blank and the fiberglass/resin.
There are some great airbrushing videos on YouTube and also a great airbrushing DVD in JC’s 101 DVD Series if you want to get a detailed look on ideas and details for airbrushing your blank.
PRINTING LOGO LAMINATES
If you would like to put some logos under your laminate, you can design them on your computer and print them out using Greenlight’s Logo Printer Paper. Once you have designed your logo, set your ink-jet printer to print on medium resolution. You need to tape the Logo Printer Paper to a regular sheet of paper, and manually feed this paper into your printer. Make sure the logo paper is facing the proper direction to receive the ink jet ink.
Once the logos are printed, remove the logo paper from the backing paper and cut the artwork/logo out leaving a small margin around the design. You should print as many logos as you can on each piece of logo paper, since you can only send it through the printer once. Details on laminating the logo into your glass-job will come up in the Glassing section of this guide.