Permatex Super 300 is a brush-on sealer that was developed to resist aviation gasoline. It's NOT the same stuff as the 3D brush-on liquid- - - -Super 300 is almost black while 3D is brown. A thin layer of Super 300, and a cork gasket if you can find or make one, should solve your problem. Most parts stores have sheet cork gasket material, and you can use your rubber gasket as a template to cut a cork one out.
Jerry



"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!