The oil cooler duct flange from Van’s is made of some very thin aluminum and is not welded all the way around. Aircraft Spruce has some spun flanges that I really would have rather used, but they don’t go up to 4″. People have had issues with the Van’s flanges breaking off, so I decided to reinforce this a bit. I mixed up some epoxy/flox and formed a fillet at the joint, then after it cured, mixed up some epoxy/micro to smooth it out a bit. Hopefully this will prevent this from ever separating.
I spread the extra epoxy/micro mixture over the fiberglass tape on the top cowl (covering the holes I drilled when fitting the cowl.
