As mentioned, fill all your gaps with filler, I use a product called Paint and Patch, from Home Depot, and then sand the side of the fuselage with a bar sander with some 200 grit sand paper. Do not just sand the CA as you will get low spots in the balsa, as the Ca is harder than the balsa. Once you have sanded with your bar sander, you will still see the CA, however when you cover it you should not see it if you are using an opaqe color of covering. Good Luck, Dave