Disclaimer: I am by no means a professional shaper with many years of experience building surfboards… just a surfer trying to share the stoke and method of building modern day hollow wooden surfboards (HWS). I have spent countless hours researching everything could find and have learned so much from trial and error. It would have been much easier attending a class by Paul Jensen (the godfather of modern day HWS) or buying a CD detailing his method of building. This would have saved time and money but then I would not feel like it was mine. The fallowing steps are what I use to build a Mahalo Boards hollow wooden surfboards (HWS). I have researched many different methods and have come up with what works best for me.

 

1. Choosing a style and developing your surfboard template

BoardCADOne of the most difficult decisions to make when it comes to surfing is choosing the best surfboard for you. There are a variety of different factors that are going to influence your choice of surfboard. Factors range from what types of waves you will be riding, level of experience, style of surfing, and conditions. Once you know the type of surfboard is right for you, you can either design one yourself or purchase a template from our templates webpage. We developed our templates using BoardCAD to create .brd files. Click the fallowing URL to learn more about BoardCAD. http://www.boardcad.com. I‘m not going to include instructions on how to use this program because the company that created the software has already done a great job of that. When designing our boards, we set the slices, or ribs, 15cm apart at load bearing areas of the surfboard and at 20cm apart everywhere else. This is to increase the strength of the board without adding too much weight.

 

2. Create your template file and print

After designing your board with BoardCAD, create all the slices needed for your hollow board which will be the ribs of the frame. Save your board and launch the HollowBoard Template Maker app created by JedAil. You can download this app by clicking this link.http://jedail.free.fr/programs/HBTM.jnlp. Once you have launched the template maker, click File/Open open the .brd file that you saved from BoardCAD. You should get a “file loaded successfully” message. Now set the parameters for you board. We use the fallowing parameters to create our templates:

 

  • Skin Thickness – 0.3 cm
  • Solid Rail selected
  • Rail Thickness – 2.0 cm
  • Spine Thickness – 0.6 cm
  • Ribs Thickness – 0.3 cm
  • Outer Frame Thickness – 0.3 cm
  • Bottom Notch Position selected
HollowBoard-Template-Maker
HollowBoard-Template-Example

 

Next you will click File/Generate Full Template and the program will create a PDF. This PDF then gets modified in Photoshop™ for the Mahalo Boards hollow wooden surfboard build method. This includes adding extra guild lines to add supports under the board to assist in the deck attachment process. After modifying the template file, it can be taken to your local print shop and printed from a large plotter for about $10-$15. You could print this file from a typical printer however you’ll need to tape numerous pages together and hope they line up right. Not worth the time in my opinion. I have found the fallowing parameters to work well with my method of building Hollow Wooden Surfboards. I use 1/8″ or 3mm thick Lauan Plywood to build the frames. The skin thickness is also very thin because you will need to to be able to bend and warp the skin easily over the frame if you have complex curves and rocker. Don’t worry about the thickness of the skin for strength, the skin gets glassed inside and out with added strips of glassing inside for strength. When ripping the planks to be laminated using your table saw, you’ll want to set the gate to about 4mm. After the planks have been laminated together you will belt sand it down to make an even surface that will be approximately 3mm thick.

 

3. Tools and supply list

I assume that you already possesses basic woodworking skills and either own or have access to the fallowing lists:

TOOLS:

  • Table saw
  • Belt sander
  • Orbital sander
  • Dremel™ with shaping wheel or mini saw
  • Knife
  • Respirator mask
  • Rope
  • Ratcheting straps
  • Hand drill or Drill press
  • Utility staple gun
  • Lots of masking tape
  • Router
  • Epoxy spreader
  • Mixing buckets
  • Paint brushes (sponge)

SUPPLIES:

  • 1/8″ Lauan plywood
  • Raw cut wood (cedar, red wood, paulownia, or balsa)
  • 1/8″ Cork roll underlayment
  • Pine 2 x 4’s
  • 30″ x 1/2″ plywood cut to length of surfboard
  • Tight Bond or Gorilla wood glue
  • Gap Filler Insulating Foam
  • Spray adhesive
  • Plastic wrap (Saran™)
  • 4oz S-Glass fiberglass cloth
  • Epoxy resin with hardener
  • Fin boxes and fins
  • Leash cup
  • Air vent with plug

 

4. Wood selection

To build the frame of our Hollow Wooden Surfboards, we use 1/8″ or 3mm Lauan plywood or hollow door skin. You should only need one sheet of this unless you plan on building a board longer 8ft or multiple boards. The top and bottom skins of the surfboard are planked using a combination of cedar, paulownia, and/or balsa wood. You will want to visit your local lumberyard and spend a few hours picking the clearest (knot free) boards you can find. I have much better luck at the lumberyards than at the hardware stores. Finding quality lumber is very important because trying to rip planks from boards with knots in them is not recommended. As far as wood selection goes, balsa if the least dense (lightest) of all the woods that we use however is more expensive, easily damaged (dented or dinged before glassing), and harder to get. Once you have purchased the raw cut lumber you will need to rip 4mm planks using a table saw. Once you start ripping planks, don’t stop until you have all the wood you need to skin the deck and bottom of the board because it is very difficult to get gate of the table saw set exact as you had before. Also, if the board you are building is longer than the lumber you are able to purchase, than you can include a chevron into the design of your board which may actually make it look better. The possibilities are endless depending on your experience.

 

5. Cut out and build inner frame

After you have printed the template, I recommend that you use spray adhesive to stick the pattern directly to the surface of the Lauan plywood. This will greatly improve your accuracy with the jigsaw (or table saw) when cutting out the pieces to build the frame. You will notice with my templates that you do not need a complex rocker table to maintain the shape of the board. While cutting out the parts for the frame, there are guild lines to leave material on the parts that create the support needed under the board to prevent it from flattening out under the pressure of attaching the deck to the frame. Once the deck has cured to the frame, you will use the Dremel™ to trim the bottom on the frame and attaching the bottom skin on your hollow wooden surfboard. If you are concerned about the strength of your surfboard, you can cut out two spines then epoxy them together to create a 6mm spine. This is not required but highly recommended to add strength to the board if you are building a “Big Guy” surfboard. Also, if you are building a board longer than the sheet of Lauan plywood, you can build the spine using this method. Once all the parts are cut out, you will then need to drill weight reduction holes. This will lighten up your frame and allow each chamber of the board to breath. The HollowBoard Template Maker provides guidance for cutting rectangular shapes to reduce the weight however any structural engineer will tell you that arches are stronger. For this reason, I drill a series of circles through the spine and ribs of the frames instead of rectangles. This is not required for the outer rail sense it’s only function is to stiffen the frame when it is ready for assembly and will be removed once both the top and bottom deck have been pressed to the frame. I have found that using a glue gun to build the frame is the fastest and most effective way to build the frame.

 

6. Laminate and attach top deck

Now that you have the frame ready and the strips for the top and bottom skin, lay them out on the floor and arrange them in the desired pattern with the good side up. After the strips are taped together to form the skin, it will be flipped over and you will be laminating the back of the deck first. To start, tape the strips together perpendicular first to hold them together starting from the middle and working your way out. This may require some pressure to ensure there are no gaps if any of the strips aren’t perfectly straight. Next run an additional strip of tape along every joint to create a hinge. There is no need for gluing the strips together with the masking tape joints because epoxy resin is very fluid and will flow between the strips of wood and form a strong enough bond to hold the skin together well enough to glass. Once the strips of wood are taped together, you will need to protect this surface from “sticking” to your working surface while laminating. Before flipping the skin over and laminating the strips together, I use plastic wrap or cellophane to prevent resin from seeping through and causing it to get stuck. Now flip the skin over, tape side down, and carefully use the belt sander to smooth any uneven joints or high spots. Next use the half board template that you had printed and use this to outline a rough shape of your board. Center the template and trace the outline giving yourself an extra inch on the outer edge. You are now ready to glass the inside surface of the deck. Roll out the 4oz S-Glass cloth over the skin and trim the edges. Once the glass is laid out, use small strips of scrap wood and use the hot glue gun to secure the ends of the planks outside of the outline you traced of your surfboard. There will be a lot of pressure used to press the deck to the frame and without securing the ends of the planks, the masking tape will not be able to hold them together under the pressure.

Now you’re ready to mix the epoxy with the hardener in the mixing bucket. If this is your first experience with epoxy, I recommend that you use a medium hardener to give you enough time to spread it evenly over the surface. Watch the time because if you allow the epoxy to sit in the mixing bucket too long, it will generate to much heat and “kick” before you are able to spread it over the skin. The sooner you can spread the epoxy over the surface, the longer you will have to work with it because the mixture needs to dissipate heat. Also pay close attention to the mixing charts and temperatures as this will effect the time you have to work with it before it kicks (start solidifying) and the time it takes to dry.

If you haven’t already built the frame of your surfboard… it time to start and if you’ve waited to this point, you’ll have to work fast. They key to building a Mahalo Boards hollow wooden surfboard is getting the skins to adhere to the frame properly. Ideally, you want to press the skin to the frame before it has a chance to cure. You should have a couple hours to build the frame before it’s too late. If you think the resin may harden before you’re done with the frame, spread another layer or resin to fill the weave and this should buy you some time. This will form a chemical bond between the laminated glass and the weave fill layer of resin. This layer of resin will serve as the “glue” that attaches the deck to the frame.

Allow the laminate to setup and become tacky but not dry because you’ll want the frame to attach to the deck before it dries completely. Once you have completely saturated the fiberglass let it start drying and this should give you enough time to prepare for attaching the skin to the frame. To attach the skin, you will need ratcheting straps, rope, staple gun and 2 x 4 blocks cut to 6 inches long. You will also need a flat surface that you can strap the surfboard to while it cures. This is where that 30″ x 1/2″ sheet of plywood comes in. To keep the plywood from warping, nail the longer 2 x 4’s to the under-side, out edge and lengthwise to give it support. You will also need these 2 x 4’s to secure the rope to with the staple gun after pressing the skin with the ratcheting straps. Make sure to use the small 2 x 4 blocks between the straps/rope and the skin of the board to evenly distribute the pressure and place them approximately over the ribs and outer edge of your surfboard.

 

7. Re-enforce underside of deck and brush resin onto frame

Once the deck has been laminated to the frame and is dry to the touch, remove the rope and 2 x 4’s blocks that you used to secure the deck while it cured. Flip the board over and use the Dremel™ with the shaping wheel to trim the excess Lauan ply from the spine and ribs that were used to support the board under the pressure required to attach the deck. Adding fiberglass of this next step is optional but I recommend doing this to add re-enforcement. Mix another batch of epoxy and use a foam paintbrush to wet out small pieces of scrap fiberglass and place them on the deck and frame throughout the areas that supports the majority of your weight. Do not forget to rough up (sand) the hardened epoxy where you plan to add extra glass for proper bonding. You will then use the rest of the epoxy to paint the Lauan frame which adds strength and prevents water damage if the board ever takes on water for any reason at all. If you are building a hallow kiteboard, you will need to add extra strips of wood and fiberglass where the foot strap and grab handle inserts will be installed. I build my kiteboards using 6.5mm sealed back t-nuts which are the same inserts snowboard builders use. You can purchase these inserts from this website: http://www.boardcrafter.com/.

 

8. Install leash cup and air vent

Now that the deck is firmly attached to the frame, you will want to install and re-enforce the components before you attach the bottom skin. Decide on the leash plug and air vent location and epoxy an extra 4mm x 2″ x 2″ piece of scrap wood to the underside of the deck for added support for each. You can also add fiberglass to make it even stronger. By doing this, it will keep the air vent straight while installing it and keep the leash cup from pulling out after a big wipeout. There are many commercial air vents out there but I have found the fallowing method to be very effective and the parts can be found at your local hardware store. You can purchase fins boxes and leash plugs from Fiberglass Supply who seem to have the best prices.

Here are the parts required to make the air vent:

  • ¼-20 x 1/2” brass screw
  • #14S brass flat washer
  • ¼” inside diameter neoprene flat washer
  • ¼-20 internal thread insert nut
drain-plug-01
drain-plug-02
Thread a nut onto the brass screw to help clean the threads after notch is cut.
drain-plug-03
Use a cut-off wheel or thin saw to make a notch all the way down to the nut.
drain-plug-04
Once installed in the deck, the screw is simply raised a few turns to open the vent.

 

10. Laminate and attach bottom deck

This is done similarly as laminating the deck. The only difference is when you fill the weave and attach it to the frame. Unlike the deck, you will need to fill the weave of the fiberglass cloth before you attach the bottom skin. For more information and details, see Step 6.

 

11. Trim edges, build up hollow rails and tail/nose blocks

Rail-and-Rib-ExampleNow that both the deck and bottom skin are attached and completely dry, you will need to trim the edges down to the outer rail of the frame using a jig saw and belt sander. Once you have a smooth outer edge that’s flat and level, you can start adding strips of wood to build up the rail. These strips should be about 1cm wide by 3mm thick. Any more than that will make it difficult to make the strips hold while drying if your board has a lot of rocker. The best way to attach the strips of wood is with wood glue and lots of tape to hold them while they dry. While building up your rails you need to keep in mind the type of rail you will be shaping whether it’s a down rail or soft rail you don’t want to sand through while shaping.

 

12. Shape and sand blank into a surfboard

The shape of the rails determines how water flows when the board is planing and turning. Different shapes have different uses. Rails are thickest towards the center of the board and thinnest at the tail and nose. Fuller rails are thicker providing more floatation when leaned on edge. Thinner or tapered rails aren’t as thick making them easier to sink when on edge. Now the harder the rails edge the cleaner the water breaks away from the board which contributes to speed and looseness. Hard rails penetrate the water poorly at high speeds and resist be leaned on edge while softer rails provide a smoother more forgiving response. If you’re new to shaping, you would be better off copying the rails on an existing board.

To properly sand the board, start with the belt sander and use a course grit. I always start with 80 grit to level the surface with the belt sander then use the orbital round sander to smooth it out starting with 150 grit to 250 grit. Note: Please use the belt sander carefully because to can chew up wood quickly… you must keep it moving at all times or it will gouge your board. Properly sanding your board is very important because if you don’t smooth it out, you will see all the swirls and gouges from the course sand paper once the resin is applied to the wood.

Once you have sanded the board completely, you will seal the wood with a very thin layer of epoxy using fast hardener. Use the epoxy spreader to completely cover your board. This is important because the wood will starve the fiberglass (soak resin from) of resin and you will see bubbles everywhere as the wood out-gasses. If you miss this step… it will drive you crazy while glassing.

 

13. Fin box installation

My boards use the Future Fins system because they are easy to install and sense I like to travel… I don’t have glass-on fins. You will need to use the router to cut into the board for your fin boxes after tracing their exact location. Please see my excerpt below regarding fins. Once this is done, you will have a board full of wood shavings and saw dust. Use a vacuum to clean it out and/or use an air compressor to extract the debris or else you will hear it rattle around after you have sealed up your board and never be able to get it out. With holes in your board for the fin boxes, you will now need to mix up a small amount of epoxy (w/ fast hardener) then pour it into the board and allow it to flow down the inside of each hollow rail for re-enforcement. By now you can see a trend here that I re-enforce my boards anywhere I can to make the strongest hollow wooden surfboards possible.

Fins have a huge impact on the maneuverability, stability, and drive of a surfboard. Fin placement can dramatically effect the performance of a surfboard and completely alter the way you experience surfing. Depending on personal preference, the number of fins, the placement relative to each other, and the location of the fins will affect how well the board turns and it’s drive down the line. Moving the fins forward tends to make the board more loose and makes it turn easier. Moving the fins re-ward will make the board more stable with increased drive. It’s also worth noting that the closer the fins are to each other, the looser the board will be. The further apart the fins get, the harder the board will be to turn by increasing it turning arch or radius however this will make the board more stable.

See the table below to better understand fin placement:Fin-Setup-Table

 


toe-in_01
Toe-in –
With a 3 fin or thruster fin set-up, the outer fins are slightly angles towards the nose and this is referred to as toe-in. Toe-in is normally set ¼” to ½” (but no more than ½”) difference between the trailing edge and the leading edge of the fin. For some boards, toe-in is such that a string from the nose of the board to the fin will align with the fins toe-in. Toe-in causes pressure on the outside of the fins to be greater than on the inside which makes the board want to swivel to either side with little surfer input making for a looser and more responsive board. Toe-in also helps the board during bottom turns by keeping the rail engaged with the wave.

fins-04Cant (rake) –  In multi-fin systems, the outer fins are angled toward the rails between 0° and 8°. Cant along with toe-in gives lift at the nose by sucking down the tail, however it increases drag and slows the board down. Cant also puts the fin where it needs to be when you are doing a bottom turn, the inside fin of the turn is angled out toward the rail and is in a better position to hold the board in the turn. This makes the board handle better on its rails.

 


fins-03Because the fin plays an important role in the way the surfboard reacts to waves, it is essential to mark the fin placement correctly. Use the fallowing steps the help you properly install the fins to your board.

  1. Find the exact center or “stringer line” of the surfboard and lightly draw a 2ft line from the tail towards the nose. This line can be sanded off easily before the glassing process and will not be seen.
  2. Use a T-square to draw a “cross line” four inches up from the tail. This is the mark for the back edge of the center fin or fins if you prefer a twin-fin. You can adjust this cross line forward or aft depending on your preference.
  3. Place the center fin on the stringer line, with the back end lined up flush with your cross line. Be certain the fin is lined up parallel with the stringer line, and then make a small mark at the front of the fin on the stringer line.
  4. Measure 11 inches up the stringer line from the tail and draw another cross line.
  5. Mark side fin placement from the second cross line, six inches out from either side of the stringer line. This marks the back of your side fins. If you prefer a wider side fin placement, mark one inch from the rail line.
  6. Line up the back of the side fins with each mark on the cross line.
  7. Now toe-in the side fins a half inch. Mark the front edge of the fins and remove. You now have fin placement marks and are ready to permanently attach the fins using a glass-in or removable fin system.

If you are building a Quad-Fin board, use the fallowing pictures to help guild you. I have also included the Mckee M4 & M5 Formula™ (click the images to enlarge).

quad-fin-position
Quad-Fin-Setup-Table

 

14. Glassing

Safety first… make sure you have a respirator mask and plenty of gloves even though epoxy is less toxic than polyurethane resin. This is a very messy process of creating the board. You will also want to protect your floor with plastic because the resin will run off the board to the floor.

Before glassing, the boards are pre-coated with epoxy that is thinned with 25% denatured alcohol for a faster flow. The DNA evaporates fast and the epoxy sets off just fine. This step is not required however, it seals the wood so that it does not pull epoxy from the glass and there are less outgassing bubbles as the glass sets up.

Once you have the board shaped and ready for glass, you will need to tape off the fin boxes, leash plug, and drain hole. You will glass each side of the board (deck and bottom) separately, starting with the bottom using either the freelap or cutlap method. If you decide to use the cleaner more advanced cutlap method, you will need to tape off the railes of the board evenly on both sides allowing the lower edge of the tape to hang down off the rail so that the resin to drip off instead of running around the board to the deck. Before the resin is hard and dry, the tape and excess glass is cut off using a sharp blade at the edge of the tape giving you a clean lap line. Once the resin is completely dry, lightly sand the lap line and you are ready to repeat the process on the other side of the board. The freelap method will not require the taping of the edges because you will squegee the resin and cloth around the rail to the deck. This method is quicker and more difficult to master but will require more sanding once the resin has dried before glassing the other side.

After the board is “dressed,” lay the fiberglass cloth over the board and cut the excess cloth from the sides leaving about 4-5 inches to hang over the sides of the board to lap over the rails. You will also want to be wearing your respirator mask when cutting the fiberglass cloth so that you do not inhale tiny fibers that may become airborne.

Next pour the resin down the center of the board and squeegee it out evenly. Work it around the rails, tail, and nose so that the glass is smooth all the way around the rails and touches the tape skirt. Allow the resin to become tacky almost hard and pour another batch of resin to fill the weave of the cloth and hot coat the board. Doing this before it’s completely dry saves time and will allow the layers of resin to chemically bond which is stronger than having to sand or rough-up the surface between the layers of resin.

 

15. Final finish

Now that the board has been glassed it will need a final sanding and sprayed with UV Clear to protect the board and give it a finished look. Using 80 grit sandpaper, even up the glass lap lines at the rails and remove any high spots then continue sanding the rest of the board with 100 to 150 grit paper and gradually work to 220 grit for final sanding. Block out the glass until there are no shiny spots. Shiny
spots are low spots and will show when the board is finished. Once the board is completely sanded and there are no lumps, gouges, low spots, high spots etc. it will have a milky white appearance from the millions of fine scratches in the hot coat made by the sandpaper. The gloss coat will fill these scratches and make the glass perfectly clear.