design critique requested

I’ve decided to vacuum bag a surfboard, so I thought I’d throw my ideas out here and see what people think. I have, in fact, been lurking around here for quite some time, gathering info, so I could avoid asking some questions that have been answered a bunch of times already. I think I’ve finally got a pretty good idea of what I want to do. I’ve had quite a bit of experience bagging stuff, because I used to make a lot of composite model sailplane wings. I’ve also shaped and glassed a bunch of windsurfers, using extruded styrene and epoxy, so I’m pretty familiar with those aspects as well. This will be kind of a synergy of those two endeavors. I want to make a copy of an existing board, (an 8 foot, single fin, mini log), so I plan to glue up some home depot foam, using the old board as a kind of rocker table. I like Bob Miller’s idea of doing the entire bottom first; I don’t plan on using a central stringer, so I like the idea of linking the cloth from the top and bottom on the rails. I’m going to use 3/16 balsa as the sandwich material, with 4oz cloth over and under, bottom and top. I like Silly’s idea of cutting the rail material out of a big sheet of balsa ply, and gluing them up in the offcut, but I do have a couple of questions about that. I assume there will be some end grain on the rail somewhere, since the cuts have to go across the grain at some point to follow the rocker profile. Is this correct? Also, he says to use the rocker template for a cutting guide, but it seems like if you do that the pieces will come out too short, since the rocker template is a straight line from nose to tail, and the rails have to wrap around in an arc from nose to tail, following the edges of the board. I hope that’s clear. I like the idea of a concave deck, so I think I’ll try that as well. Well, that’s my plan. What do you guys think?

thanks a lot, bruce

By the sound of your understanding and experience of boards and composites you should just do it.

All the advice given here will help, but it’s your own hands that will get the job done. And whatever eventuates will be a good learning experience. Some of the boards made by first time boardmakers on this forum just blow me away.

As for the balsa layup vac sequence etc, it may be your first, (maybe not?), but probably not your last. I won’t comment as I haven’t done a board this way yet, but I’m sure it will work.