As you may know, the final CG location can only be determined after test flights and trimming and depends on the personal preferences of the pilot. Most pattern planes behave well at 35-40% CG location, so 35 or 37 will be a safe starting point. You will need to determine first the MAC (Mean Aerodinamical Chord) of the wing which is the chord located in the center of Area of the wing, on that chord you have to determine the CG that you want, NOT at the root Chord. Determining the MAC is very easy using a graphical technique, and it works for both single and double tapered wings. If you are interested in using this method please let me know and I can post the detailed instructions and a drawing on how to do it