Okay, I've finished my rocker table, the surface is 1/4" mdf, just put the final touches on my vacuum pump, works like a charm, cut out my template and now, I'm ready to build my light wind machine, 146x46 My thoughts were as follows;

1/4" dyvinacel core with the perimeter routed out and poured PU rails or epoxy with micro balloons poured as rails,

An added 1/4 deck that tapers to the edges for added firmness with 4 oz glass sandwiched between

A layer of 6 oz e glass ( is s glass that much better for my first board) followed by 2 - 4 oz layers on either side of the core.

All this layed up on a sheet of Mylar and vacuum bagged.

Not sure about the top sheet, might try to find some cotton print for the first board. Also probably going to use a tint for the bottom, so it'll just be a solid yellow or orange.

With this be okay?. To think, to thin?. Any thoughts.

Thanks,

I'll post pics as things progress.

The 1/4 inch divinycell needs more then 6 oz of glass or it can snap. I'm repairing one right now in 135 x 40. Other then that sounds good. Wax up the masonite and it works good. Not quite as smooth as plexiglass but it works.

3 x 6oz e glass both sides plus 6oz patches under feet on deck and you are good i think.
Show pics!

Thanks for the reply. Is there a huge benefit to S glass??? So much more money. And wax the masonite with what?? I'll take some pics this weekend and post

Am I right in understanding that the core will effectively be 1/2" in the middle tapering to 1/4" at the edges? If you want to save some weight and cost skip the layer of glass between the two layers of foam. That layer is at the lower stress "neutral axis" area, and will do very little for you.

A good rule of thumb for basic E glass is 3 layers of 6 oz each side no a half inch core. If the board is wide and you're not huge you could get away with a bit less glass. Now, if you go S-glass sounds like your layup is about right using the 4's. If this is your first board, I'd suggest 3 layers of 6oz E, and drop more cash as you learn a bit more.

Your original plan had 32 oz total of S-glass, includuing the middle layer. You'll be at 36 oz with 3 layers of 6 oz E each side, so not a huge weight difference. Unless you plan to really stress it, go with 2 6's and a 4 each side of E. Or, if you can find it (like if you're in Canada getting stuff from Composites Canada) get the 7oz style 7715 E glass, which has 90% of is strength in the long axis and replaces 2 layers of 6 oz for a better price than S-glass.
http://www.compositescanada.com/product ... roduct=613 (note that the description on that page seems to be wrong, the same as anothe type of cloth, but the pdf link on that page has the right info.)

HTH,
Peter

Thank you so much for the info. I'll post picks this week end.

Well, I clearly haven't posted pictures yet. Got suddenly very busy at work. Hoping to make the first board next week. I'll put up pics as soon as I have something.

D