got a '73 nova hatchback. i bought a new hatch off an omega then sandblasted it and primered it. i havent had time to put a sealer on it yet and its been sitting for a little over a year like that. im starting to hear rust flakes from the inside when i open it all the way. is there some sort of epoxy i could fill the hatch with that will dry hard and stop the oxygen from progessing the rust? besides it rattles with the stereo up loud and those two layers could use support in between. any ideas?