pic: Another Cheap Wood Frame Idea

[Rick TYler]

Originally Posted by CraigHickman

I've had nothing but success with both Kevlar weave, as well as Carbon Fiber. Granted, these are in Longboard applications, but those tend to have a little more force involved (a 200lb rider going through a 90 degree turn at 60mph). As long as you take the time to lay out all your steps right, and then don't dawdle when working with the actual glass, you'll be fine with both these materials. If a team has the budget, there are some IMPRESSIVE things that can be done with composites. Heck, I'd LOVE to build an entire robot out of the stuff. Foam molds and vacuum bags galore!

My background is in amateur boat-building where the object being made is too large to bake and usually wildly impractical to vacuum bag. If I needed the penetration protection of Kevlar, I'd cover it with a layer of glass cloth to prevent surface fuzzing, or, even better, get an expert to design a layup schedule that included some biaxial cloth for strength mixed with Kevlar. Usually, in amateur boats you find carbon fiber cloth in spars and blades -- not usually in hulls. Longboards use a lot less material. Carbon fiber in quantities big enough to build 20- or 24-foot boats is really pricey. Carbon fiber is also a pain to cut, it floats in resin (which is why it is usually vacuum bagged), and fuzzes if it's on the surface. The carbon fibers are usually considered dangerous to breathe, so you want to wear a respirator or at least a NIOSH dust mask when cutting.

I do think carbon fiber tubes are The Bomb for robot arms, but haven't had a chance to try it due to the famously conservative students on the FRC team with which I used to work.

We need some pictures of your longboard(s). Here's a link to pictures one of my boats: http://www.jemwatercraft.com/images/...ahPictures.htm, made from 4mm okoume and 6-ounce fiberglass. And other stuff!