I previously used the vixen file to shape the flange around the spinner on the lower cowl where the upper cowl overlaps. This left the flange pretty thin (to the point that I could easily see the shadow of my fingers through it when a bright light was on the other side). To strengthen the flange, I mixed up some epoxy/flox and spread a coat about 1/8″ thick.
I also trimmed the propeller flange on the upper cowl. Once I fit the cowl halves together, I make sure the cuts line up.
