Stub Wings
These pictures all show the steps in building, foaming and glassing of my stub wings.  As you can see from the photo immediately above, I used spray polyurethane foam for the fillets.  However, I found several airhole bubbles as I sanded this and finally I just ripped it out and used the urethane foam that the rest of the plane uses.  This sanded easily and, as you can see from the photo to the left and below, turned out real nice.