There was a heck of an interesting article on shellac in this months issue of Woodenboat.
The article talked about getting dried flakes and then using denatured alcohol to get it to the desired thickness--ie. very thick for using as a bedding compound, medium thick as an adhesive, and thinner for a finish.
I doubt many (if any) folks are using shellac on a frame, but I'd recommend checking out the article for other uses.
