losethestraps.com

hi, i'm planing to build my first skimboard (i weight 105 kg, i know i need to workout) , i'm want to keep it simple, plywood and glas on both sides, then put it all on rocker table (right now i'm building one http://www.kiteforum.com/viewtopic.php?f=107&t=2370286 ) ill use vacuum baging.
I'll use nobile skim template http://www.kiteforum.com/download/file.php?id=20609
1" of nose rocker (enough?) and the back 2/3 of the board dead flat
I'm thinking about tail rocker maybe little concave???, any advice on that ?
i need advice what thickness, 2 X 4 mm= 8mm and one layer of glas on top and bottom ? i'm not planing on jumps or something radical, just joy machine in light winds, so i want to keep it light but still sturdy, but flexible to keep my knees safe in chop (i ride 2008 nobile 555 i love it but i hate it in chop conditions ):D
thanx in advance

2x4 mm might be a bit thin and flexible. Maybe 3x4 is better. If its flexy then you need next to no rocker as the flex will provide this so yeah 1 inch nose is fine. Keep it as light as possible.
Best of luck.

I would agree with slyde on this one. 2x4mm is really flexy, would probably work if you weigh 40kg or so. 3x4mm can be sturdy enough if it's the right sort of ply (rather dense wood as used in marine grade ply), but then you're getting a lot of weight. Glass will add stiffness only according to the thickness of your board. It doesn't make a lot of difference if you slap on 1 or 5 layers of glass on an 8mm core if you want a stiff board - won't be stiff enough.

At your weight, I would go for a board that is at least 2cm thick, and have 2 to 4 layers of 4OZ on top and bottom, depending on the core material. Core could be foam or balsa or a hollow plywood construction filled with foam; massiv ply core would be way too heavy.

ok, change of plan, lets say i can get my hands on balza (50 x 1000 x 8 mm) strips, thinking about sandwich. glue some strips to desire width, two sheet, then glue them one on other so ill have 16 mm thickness core, and glas core (how much glas would ure recommend ?) on rocker table ?
thanx in advance ?

If you can get the balsa thinner you could build a "compsand" (composite sandwich)

http://www.compsand.com/

top and bottom skin separated by a layer of low density foam (polystyrene)

Strength and stiffness is still a function of the thickness but some of there surfboards are glassed with 2oz either side of the wood skin making really light surfboards. Probably to light to kite with?

just balsa i would have thought 2 x 6os on the bottom and 3 x 6 oz on the top

Kev

16mm is still a bit thin but probably OK. Most foamies are 20mm. Laminated Balsa sound OK to me. Its a bit denser than divinicell so I doubt you would need more than 2 layer 6oz glass top and bottom maybe with a little extra for heelpads. but try to keep it light. If you're laminating the balsa the weight will start to climb and the balsa will soak up quite a bit of extra resin so maybe prekote with a thickish microbead mix to seal the wood before glassing. I also suggest adding a little extra resin on the edges where you may well grind on the beach in the future.