Carl and Mary
Your crochetting idea is already in production, Forte RTS http://www.forterts.com/per.html uses a computerized braiding machine to make carbon parts. This technology is directly from the weaving industry. The carbon (or whatever fiber) is wound around a mandrel, so you need a mandrell in the shape of your part. As its being wound, it is impregnated with epoxy. It is then put in the autoclave, and cured at elevated heat and atmosphere. The result is strong, light and very reasonable priced parts. I bent 4 aluminum booms (falling on them) before I got a forte boom. I have beams, spin poles, booms and tiller extensions, and tiller connectors. The only thing is that the outside "skin" is an "uncontrolled surface" so its not smooth, it has texture and it needs to be UV coated. Tony will make you spars to your specs for very reasonable prices.

also, ebay carbon is a rip off. Go to carb.com for the best prices that I have found on the internet. 5.7 oz carbon weave 30 inches wide is $14 per linear yard at carb.com. 50in wide is like $20 and I have seen it at over $45 per linear yard other places. Ebay was even higher, its some guy selling his scaps, or selling sheets with epoxy already hardened to people for accent parts in their cars. Carb.com is in Hawaii. They told me prices were going up. Order now.

I also found good prices on nomex from http://www.plascore.com/ they were about 1/2 the price for 1/4,5lb,ox - a 3x8 sheet was $50. The lead time is 6 weeks.
I talked to Wade.

Wouter, Your 14kg figure for an A cat sounds low. 17kg-18kg target is what at least 6 new home built A cats are shooting for - check out the pictures http://intcanoe.us/mygallery/index.asp?offset=0 17-18kg is a total hull weight. I used 5.7oz carbon, 1/4 corcell foam and 2 gallonsmas epoxy with 1 gallon hardener. The hulls are 6 sq meters. I got 4 hull halves to weigh between 6kg, and 6.1kg, no paint, no gel coat, no dagger trunks, no sterns, no bulkheads. My all up hull target is 17kg. The trunks are super light high mod carbon Hall parts. I think they weigh 30 grams each. The biggest unknown is the finish - paint can weigh 3 kg per hull.

Any ideas on lightweight hull finishes? How about wood veneer? How about wood printed paper? How about a hawaiian print fabric? All white is boring.

Bill