Beauty Matters, the Boat Project Part 2
Making a 14' SUP board
This is the first SUP board that I designed. The board is a calm water cruising board at 14 feet x 30 inches (4.25 x 0.77 m) and weighs 33 lbs (15kg). It was designed for a paddler of about 175–185 lbs (80–85 kg), so that the transom just touches the surface to allow clean release of water without creating drag.
It is made from 1.5mm and 0.9mm thick three ply bamboo plywood and is sheathed in 100gsm (3oz) woven fibreglass cloth. The form was modelled in Rhino and all the pieces were cut out on our CNC router.
I built it with the help of Alyssia Beloso from Belgium and Piek Kuppers from Holland, interns who were working with us at the time.
At the World Wood Day event at the Long Beach Convention Centre, CA from March 21–25 I will demonstrate the making of a 12' 6" version of this board. Come along if you are in the area, or follow daily posts on my Facebook page and on Instagram.
There are ten bottom strakes that run longitudinally. These are pulled together with tape and placed in the base cradle. The accuracy of the computer drawing and cutting ensures that when you pull the strips together they perfectly recreate the form of the hull.
The internal honeycomb of frames is slotted together dry, in place over the bottom panels.
Solid ash stringers are added, a 4x4mm square one along the rail and two at 3x7mm where the deck rolls down to the rail.
The transom, fin box and central carry handle are fitted — the framing is now complete.
Now the entire internal framing structure is lifted off. The inside of the bottom panels is coated in epoxy resin and while it is still wet the framing is dropped in place. Weights are placed on top and tape pulls the edges tight along the rail.
The next day all surfaces of the framing are coated with resin.
The deck is made from diagonal strips of 0.9mm bamboo plywood which is so flexible that it bends easily around the curve at the sides. There is an extra layer of this plywood over the flat centre sections for added stiffness. Each strip has to be shaped slightly with a plane along one edge to fit the previous one. About a third of these strips are taped together at a time.
Each one third section is then peeled off, coated with resin on the underside and then laid back in place. The ends of the diagonals are taped tightly round the rail onto the bottom. Weights keep these pieces down in the centre.
Now that the whole thing is glued together on the inside, all the tape can be removed from the outside and the edges cleaned up and sanded.
100 gsm woven fibreglass cloth is used to sheathe both sides. The top and bottom layers overlap all along the rail to give extra strength where it is vulnerable.
A small trim router is used to open up the slots for the fin and carry handle. After lots of sanding, one more coat of resin and three coats of spar varnish the board is ready for the water.