When I retired from work I had a EPS blank that I had been shaping by hand over the last year or so on a shelf in my garage. Now I had the time to complete the build.
The materials used are as follows:
Core/blank - EPS 2" thick (Home Depot)
Bottom and stringer - Hardwood underlayment around 1/8" thick (Home Depot)
Fins - Birch plywood 1/4" (Home Depot)
Fiberglass Cloth - 6 oz. surfboard cloth (Fiberglass Coatings)
Epoxy/Hardener 2:1 (Fiberglass Coatings)
Microbaloons and colloidal silica (Fiberglass Coatings)
Leash Cup (Culprit Surf USA)
Paint - Appliance epoxy spray paint (Home Depot)
Traction Pad (Agenda Surf)
I first glued the bottom underlayment to the blank with epoxy (with microballoons/silica)to set the rocker. I then cut a notch in the top of the blank down the center (completely through the blank to the bottom) for the stringer. I poured some epoxy in the notch and placed the stringer wrapped with fiberglass cloth in the notch and completely filled the notch with epoxy to the top of the board. I had to sand some of the stringer down to the top of the board as it stuck out about 1/8". I placed the surfboard leash next to the stringer and epoxied it in. Filled in the leash cup with flour. Laminated three layers of 6 oz. cloth to the top. In between the first and second layer I cut several circles of cloth and overlapped them laminated them where I would be standing on the board. Shaped the fins from the birch plywood using a production surfboard/kiteboard fin as a pattern. Epoxied the fins to the bottom/underlayment using 5 minute epoxy. Laminated 3 layers of 6 oz. cloth to both sides of each fin with about 2" of additional cloth at the base of each fin to firmly fix it to the bottom. Laminated 1 layer of cloth to the bottom of the board with an additional layer around the fins. Sanding and sanding, adding a smoothing layer of epoxy with microballons/silica, and more sanding to get everything smooth. Cut out the inside of the leash cup. Then painted the entire board with white appliance epoxy and added the design to the top front of the board. After a few days to allow the paint to cure I added the traction pad.
I've ridden this board for over 30 kiting sessions several in heavy chop (no wave riding yet or surfing). I've ollied the board many times and have put it through some pretty heavy stresses and It has held up exceptionally well, no heel dents or dings at all. It is a bit heavy but I built it to be "bomb proof". The cost of the materials invested is around $120 US (The traction pad was the most expensive part $59 US).
If anyone has any questions about the build I will try to answer them promptly.