Tips on building a ply skimboard

[Jeza]

Hello.

I'm looking for some tips on building a simple ply skimboard (nothing as fancy as tungsten's). I've built a couple of door shaped finless TT boards which i use in light winds, but would like to give a strapless skim a go instead, they look like a more exciting option. Also hoping the skim might extend the useable low end range on the kite by a knot or 2.

I plan to base it on the size and shape of the phase5 prop, using either 12mm or 16mm ply. I hope to soak the wood and bend in enough rocker that it keeps a bit in the nose and tail, as i've done with the other ply boards i've built. I'll probably seal the board with polyurethane for a start at least, though a coat of epoxy might help keep the rocker a little better i guees.

The main questions i have are:
- Will 12mm ply flex too much without an epoxy coat?

- I see square rails talked about a lot, can someone explain these to me. I was thinking of somethine like a 60 degree downturned rail with fairly sharp edges.

- On my finless door style ply boards i used to find it very easy to get pulled off the edge in gusty conditions. I cut a couple of parallel channels 2-3mm deep using an electric planer and this has made the boards a lot more grippy and stopped them sliding out when switching from rail to rail. Do you think this would help on a skim, or is it less likely to be a problem?

Any tips much appreciated, thanks!

[tungsten]

Hi Jeza, it all depends on the ply you are using. Supposed you are using a light quality, 12mm would flex too much. If you use a heavy quality (marine ply), the board will be a handful in terms of weight. You could add a lot of stability if you glue a 5cm wide rim of 12mm ply on top of the 12mm board. The glued-on rim allows you to add a rocker line which stays in. Use urethane glue and press the whole thing into shape. This way the board stays light, and you have 24mm of rails which is nice. Give it 2 or 3 coats of boat varnish and you're done. Start with square (sharp) rails, ride it, see how you like it, and sand them down if you don't. Repaint the rails and try again. that's an easy way to find out what you like best. Then you go ahead and build a second board, light, using 3mm ply / foam / 3mm ply, and glass it.

The channels are a nice idea which I haven't tried. Good thinking, I will test this!

cheers, tungsten

[Jeza]

Thanks for the suggestions tungsten, i handn't thought of gluing a rim to the top side of the board to add strength while still keeping things fairly light - i'll give it a go at some stage. Thanks for the tips on the rails too, something else to play around with.

The channels worked suprisingly well on the door shaped boards, better than i was expecting. I just clamped a bit of 4x2 down the centre of the board as a guide and ran a 75mm plainer either side of it a few times to get the channels 3-4mm deep right from tip to tip. I was hoping to keep the boards finless as they're good for cruising in the shallows and this definately helped.

Cheers!