carbon on the brain
About a year ago, I bought a surfboard designed by a shaper down in northern San Diego and made under the ...Lost label. The board was made of EPS (extruded polystyrene) foam and glassed with epoxy and 4 oz fiberglass cloth. Anyways, the board was expensive due to the fact that Clark foam decided to shut down after 20 or so years of production because of California's ridiculous environmental regulations, which make it impossible to do anything. I remember, even when I was in the Navy, we were paranoid about the EPA watching our hull painting and chipping while we were parked on the pier. I can only imagine how bad it must be for a manufacturer. That aside, this board turned out to be of rather shoddy construction. There were sand-throughs on both rail laps, the glass job wasn't very heavy, and the epoxy appeared not to have been post-cured hot enough. I'm fixing it right now (remember: there are few problems that can't be made worse with a dremel) and learning quite a bit about epoxy and some of the newer methods being used to make boards, because it's getting expensive to buy them, especially given how poorly they last.
This lead me to start reading up on vaccuum bag board building. The idea is that you make a mold, coat some carbon fiber or fiberglass weave with epoxy or resin, lay it on the mold, put a bag around it, and suck the air out until it's within some percentage of a vacuum. This makes a hard part, in this case, 1/2 of the shell of a surfboard. Parts can be made harder using more layers of cloth and better vacuums, higher pressures, and higher temperatures. Boeing is using this process to make its new Dreamliner. Composite construction for aerospace, incidentally, was pioneered by Burt Rutan back in the 70s, and is now being used for Space Ship Two and Virgin's Galactic's new fleet. More interestingly to the gun enthusiast, Bushmaster and other gun companies are using it to make receivers. It's 40% lighter and stronger than aircraft aluminum, they say. Super. And all that's needed to make something similar at home is a vacuum bag, a refrigerator pump, carbon weave, and a pourable amount of the right epoxy. Here are some guys vacuum bagging there own carbon-fiber bike frame (moldlessly). Another technique is carbon fiber infusion. I think that Bushmaster's efforts could be duplicated at home.
PRCalDude
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Reader Comments (3)
I would do a pre-preg carbon fiber. Everything is ready to go with the exact right amount resin/fiber ratio. Saves muss and fuss. I saw MythBusters use an electric blanket to 'autoclave' a project. I don't think carbon fiber is UV resistant, so keep that in mind.
Also, I think that if one of your surfboards is a little misaligned, it will qualify as a carbon off-set. :)
Several of the guys on Compsand have tried the same thing. I guess it works pretty well. Of course, you can just stick small parts in your wife's oven to post cure them, as long as they're still attached to the mold.
As far as UV resistance is concerned, I think a coat of paint is all that's required there. Like I said, they've been doing this since the 70s, and Boeing's using it for its new commercial jets.