Hollow Wood Surfboard CNC Kit – Step by Step Guide
The ribs and spar are cut from high quality mahogany plywood. You simply snap out the parts from the backing and get ready to build the frame just like an aeroplane wing.
The parts fit together to form a strong, lightweight frame. The numbered ribs are slipped into notches in the spar with the matching number.
Ribs are spaced about every 6 inches for maximum strength.
The ribs and spar are mounted a couple of inches above the building table using scrap sticks and a hot melt glue gun.
Now the wood wood planking can be added. The middle strip is critical and is the first one placed. The other wood strips are added two at a time and the glue allowed to completely dry before the next two strips are installed.
Plastic wrapping film is stretched into a string and used to tie the planks in place while the glue dries. It is very strong and eliminates the need for dozens of expensive clamps. The plastic string is looped around and under the ribs so that it holds the planks to the ribs as well as to each other. This system results in strong, gap-free joints. Detailed pictures in the manual that comes with each kit show the process.
Once all the planks have been glued to the deck the frame is extremely rigid and can be released from the building table. The sticks that were hot glued to the ribs are simply snapped off. A longboard sanding block is used to remove any glue spots. Once the ribs are all flush, the bottom planks can be installed. You have the option of installing one plank at a time (as was done on the deck) or gluing the planks together to install it as a single piece. You can even cover the bottom with plywood.
Blocks are added at the tail where the fin box and leash cup will be placed. The blocks can be made from balsa or other light woods. Scrap foam from a discarded surfboard can also be used. Once the bottom is installed and glassed, a router is used to make the cavities for the fin box. If a glass-on fin system is used the blocks aren’t needed.
The bottom planks are installed and rough trimmed to match the deck. This board was built with hardwood planks on the deck and balsa planks on the bottom. This combination makes for a very strong yet light board.
Then the edges of are carefully sanded until the deck and bottom are even with the wood strips on the end of each rib. This ensures that a perfect outside contour is achieved.
The rails are built up in layers using balsa. You can also alternate dark and light wood strips to make layered pattern. The strips are bent as far as they will go without breaking then they are cut off square. Wood pieces are cut and fitted around the tight curve. The manual supplied with the kits shows all the steps in detail.
Photos and text supplied by Wood Surfboard Supply Ltd.