Gil,
I use Minwax clear lacquer all the time. But, it will eat the foam and is NOT fuel proof. I've tested it with glow fuel to confirm my suspicions. I use it just like everyone else uses clear dope. I don't use dope, but have found this product to work very much the same. I use it to "glue" silkspan/polyspan, to seal balsa before priming, and mixed with a little talc, makes a good filler coat. Good product, but not for a top coat.
Paul