Composite Sandwich Construction Start to Finish

[Surfdad]

Out of the bag and ready for the final external lamination and sanding. The board looks like this:

[Surfdad]

The nice pinlines that you see on custom made surfboard are design to hide the transition between the laps and the rest of the board. I am NOT an artist and my etch-a-sketch is still in use this morning. The concept will be to paint some broad design to hide the transition from the carbon to the corecell - something like this:

[Surfdad]

A few points I wanted to touch on in applying a rail tape like this. I didn't get good pictures, but I used a wetout table to get the carbon wet with epoxy before laying this on the board. There are a few ways to apply a laminate, one is to drap the textile on the board and then pour resin out and spread it. This is the typical process for Polyu boards. Carbon is a little tougher to wet out and you can't really work epoxy into a textile, it tends to FROTH when worked too much.

A wetout table can be constructed in any number of ways, but I simply use an appropriate length of plywood and then I drape a sheet of polyethelyne over that. Literally NOTHING sticks to polyethelyne. Also, the Polyethelyne acts as a barrier, so as I am pouring the epoxy over the carbon tape, it stops at the plastic and so soaks both the top and bottom of the tape.

I did one tape at a time, wetting out and then laying up on the board.

Carbon CAN be significantly stiffer than fiberglass, but a great deal is dependent upon the resin used to laminate the Carbon. You want to use a resin that has a HIGH modulous of elasticity - that is to say when cured it's STIFF. I used TAP plastic's SUPER HARD 4 to 1 epoxy to laminate the carbon over the rails. Which, if I haven't mentioned it before is one of the benefits of building a comosite sandwich...you have the freedom to choose the materials inclusive of foam, textile/fabric, resin in various compartments of the board. Resin infusion which tends to be considered more advanced, you don't have the luxury of choosing resin. As such, for a resin infused board, the entire construction will have the same resin. Whereas, when bagging, we can use one resin for the bottom skin, one for the top, another for the rails, and still others for the external lamination.