: As I read it, they call for laminating a layer of glass fabric onto the outer
: hull by using thinned varnish -- NOT an epoxy or polyester resin!

: I wonder how much strength that would have and whether it might be a cheaper
: alternative for covering the outside of stitcha and glue constructions.

I had thought about using varnish instead of resin but decided against it. I don't think good varnish is much cheaper than epoxy and it is not as good an adheasive. I suppose it is more UV resistant and thus you don't need to add as much material as if you were using epoxy plus protective layers of varnish, so there might be a slight weight savings. Otherwise, I don't see much advantage to using varnish instead of epoxy. Epoxy is good stuff and why not use the appropriate material for the task.