Sanded the edges of the lower cowl bottom piece where it was bonded to the cowling. Filled the junction of the cowl and bottom with polyester filler. Sanded the filler smooth. Removed the foam and drywall filler from between the old cowl bottom and the inside of the new bottom. Trimmed the edges of the original bottom close to the new bottom where they join. Put epoxy and microballons mix in the crack between the old and new bottom on the inside. Put a layer of fiberglass 2" wide tape over the filled joint and bonded with epoxy.