Depends on the type. I believe that oil based poly will do a moderate job up to about 15 or 20% nitro. Don't quote me as fact. If you have normal epoxy, you can thin it with denatured alcohol, or put some on the area and hit it with a hair dryer to make it run. Not much is needed for this area, because it will be cold fuel and not hot exhaust residue.
Good luck,
Curtis