Plans say" The edges of the T-00001 Fuel Tank Skin must have a zero to 1/64 [0.4 mm] gap between the adjacent wing skin edges. A larger gap may be desireable if the aircraft is to be painted, while zero gap may be desireable if the aircraft is to be left in natural aluminum." Right now I have zero gap with a very tight fit and it looks great. What potential problems are there with leaving this a zero gap vs filing edges to make a gap for a painted wing. My concerns would be a lack of expansion space and its effect on cracking paint.