Hey Bruce,
For what it's worth, I use dope to
attach cloth hinges. It soaks through
the fabric nicely and if something doesn't
lay flat I can wet it with more dope and
rub it flat with a finger.
I dope the balsa areas where the hinges
go before I apply the cloth.
I use polyester cloth for hinges and
for covering on large planes.
Cheers! - K.