I applied electrical tape around the edge of the wing skin, then added Aerosil to the excess resin and used it to fill the gap between the skin and the pre-moulded edge of the flange on the tip. I wouldn't have had to do this except that the trailing edge of the tip wasn't parallel to the flap/aileron in its normal position, so I had to seat the tip slightly further in at the top and out at the bottom to achieve the correct alignment.
