: . . . but it seems to me it is mostly amateur
: boatbuilders who are willing to share info about lightweight
: composite materials construction.

Amateur aviation builders may be another group with similar interests in modern composites. Probably this would be two groups--those who make flying model planes and those who make aircraft they can travel in.

The Experimental Aircraft Association is a good group to google as a start.

: As a start towards learning about composites, I just bought the
: last produced edition (1987) of the "Boatbuilder's
: Manual", edited by Charles Walbridge, a book which many
: kayak and canoe boat builders like.

: Perhaps 1987 is old enough that materials and techniques are out of
: date.

It is solid information, although the latest reinforcing fabrics which come from mills today won't be made into products for months, and test data on them won't be available until after years of use--so the only up-to-the-minute info is from websites.

: Does anyone know of a similarly comprehensive modern discussion of
: composite construction and materials techniques?

Ask Sam McFadden what he's reading. I suspect there are several journals on materials and composites, geared toward the academic/engineering audience. As a beginner this may be over your head--but that may encourage you to do some studies in fascinating areas you would not otherwise dream of. Amateurs historically have done well when compared to pros.

: I'm not sure how to judge it, but many sellers of composite
: materials have somewhat less comprehensive on-line info on their
: websites, e.g. (not a comprehensive list):

Sometimer they assume their audience is buyers who already have a grasp of the basics. It may not be cost-effective for them to spend time with someone who is buying less than a truckload of their products. It is sad.

: Anyone have any ideas or sources of information? I am a beginner
: and don't want to get real complicated.

www.fiberglast.com used to have some good online info, and sold books and videos. I haven't visited their site recently.

Sometimes an email to a contact address at a manufacturer's website can get you more info than what is online. Explain that you are designing and building lightweight boats and they may be able to gear their response in your direction.

Hope this helps

PGJ