Saturday, October 28, 2006

Kiteboard Construction Notes

First Board- 152 x 44, Plywood, "Close to the Edge" 1/2" Baltic birch, planed down on edges & tips (on top only), to reduce weight, increase flex, and create thinner rails. I used a hand held power plane to rough it out, then small belt sander to make smooth. Covered the top with putty to fill grain and voids and sanded with random orbit sander. NOTE- next time sand more to thin rails to 1/8" or 3/16" all around for better grip in the water, less weight and added flex.

Cost of wood- $25, (half of a 60" x60" sheet). I taped off the edge and sprayed several coats of flat waterborne paint on top, left bottom unpainted, applied graphics, brushed on 1 coat of epoxy on top and 2 on bottom. NOTE- next time seal bottom with clear spray on finish and topcoat with 1 coat of epoxy to save weight, (1 coat of epoxy over bare wood isn't smooth enough).

Inserts for handle & footstraps- brass, from McMaster & Carr.

Holes for fins drilled big, filled with epoxy, redrilled.

Fins- $40. $10/ea from New 10-24t two hole mount Kiteboard Fin - 2.0 Flathead Gloss
. I tried smaller home made ones but they were slipping out. These work much better.

Handle- mahogany, pattern drawn on with magic marker, cut on band saw, sanded on stationary belt sander.

Pads, stick-on, $20 for pair. Straps- Dakine windsurfing straps from an old board.

Graphics- "Close to the Edge", digital file from Internet printed on water slide decal paper. Rolling Stones mouth- sticker. I tried rice paper made for surfboard graphics, looks good but it requires about 3 coats of epoxy to cover it. Note- next time, for clear decal, use clear matt label paper, put a layer of sealer or epoxy down under the decal.

Epoxy- 8 ounces per coat, clear boatbuilding epoxy, $10.

Update- How did it ride? It was O.K. in flat water/ light winds. It really went upwind well! Problems- no flex, heavy, no rocker, wide tips. Symptoms- I had to use a lot of back foot pressure to keep the tip up in any chop at all since it had 0 rocker and wide tips. I got a lot of thigh burn using this board, same muscles as skiing. It splashed in my face a lot. Retired after about 1 year.

Second Board- 132 x 41.5, Plywood, "Storm Chaser" 2 layers of 1/4" birch plywood glued up with 1/2" of rocker on each end, planed down on edges and tips (on top only). Cost of wood-$0, I used scrap from the shop.

This board was lighter than my first and had some flex but otherwise had many of the same problems as my first board, not enough rocker, tiring on legs, spray in the face. Retired after 1 year.

Mad Cow- 180 x 60, Pink foam, fiberglass, plywood bottom, twin tip surfboard.

This is the ultimate light wind cruiser. It works down to 10 MPH with 17 meter Zephyre, or 8 MPH with Flysurfer 15 meter Speed 2. Very light weight board but extremely delicate, not enough layers of fiberglass cloth on top (1 full layer with second layer under footpads and handle). Plenty of rocker. Fun sometimes. Pink insulation foam is cheap but outgasses when it heats up. This causes delamination bubbles on the board if left face up in sun on beach. Still in use until it breaks.

Plywood skimboard

This board has rocker and concave. I'm still experimenting with it, want to try it with small fins for better upwind grip. It has almost no flotation, which makes waterstarts hard. I think that's why most kite skimboards are made out of foam.

Link for Wooden Surfboard, made from scrap, with hollow chambers-

May 21, 2011
Scoopers Home for Wayward and Delaminated Boards- I took Jean's broken foam core Mako into the shop to give it some TLC and to save it from the trash can. I know this old board has some stories to tell. I'm hoping it will whisper them to me the next time I take it out in some wind. Here's how I tried to bring it back to health- Click on pics to see large.

Prep- I cut the ragged edge of the old foam to make a clean edge, and removed a few small pieces of foam that were left around the fin holes. I sanded the fur left from the foam on the top and bottom sheet but it was coming off slowly so I mostly left it.

Making Parts, Edging- I glued up Versatex PVC board to make a blank for the new edgeing. Traced the shape from the board and cut it out, sanded it by eye to get the taper on the edgeing.

Foam- I used Last-A-Foam, from Fiberglass Supply, to make a new foam core section. I traced the PVC edge onto the Foam, cut it out, sanded the foam to the thickness and concave by eye. Used a knife to cut out the hole for the old fin hole reinforcement block, (which looked like solid thickened epoxy).

Glue Up- I glued the whole mess together, old top and bottom sheet, new foam, new PVC edging, old fin hole block, with lots of West epoxy. It was more floppy than I expected so I put small clamping blocks on the place where new edge meets old edge to get rid of sag there while it dried.

Fiberglass Reinforcment- I have low confidence in the strength of the repair. After all, the original construction wasn't strong enough and the repaired board will always be less strong than the original. So I sanded the bottom, put 1 layer of cloth over the bottom of the board, 3 coats of epoxy. I tried to wrap the cloth around the edges but it didn't work, should have used thinner cloth. You can see the texture of the cloth if you click on the picture to see large.

The Result? It looks almost as good as new, feels a little heavier. I know it will work but not sure for how long. One session? Stay tuned.

Follow up- The board is probably a little heavier and stiffer than the original but has worked great as my main board in waves and chop for almost 4 years. The other end just started to delaminate. I reglued it and it's back in the rotation.


Slingshot Octane said...

Thank you for the notes, i really appreciate that you are sharing them with all your readers.


scooper said...

Robert, Thanks for the comments on my board! The 2 things I hear when people see it in person-"wow, it looks great!" "Wow, it weighs a ton!" The jury is still out on how well it rides.