Okay, I'll add my question here. What are your feelings on fuelproofing with butyrate dope, everyone? It was the standard covering method for many years, and it's still widely available (especially if you know someone who messes about with full-scale bipes, as does my father ). I ask because I have a kit built up and partially covered right now with 3 coats of butyrate on the firewall, fuel tank floor, etc, and figured I'd solicit opinions on it's projected longevity.