The wing in this kit is built plenty strong without any fiberglass. Don't add the weight or the mess. I recommend enlarging the ailerons though, I was very disappointed in the roll rate when I first flew my Cap, it wasn't what I expected. After flying mine for a few years I enlarged the ailerons 50% chord-wise, removed the torque rods and installed a servo on each wing halve. This plane is more fun to fly now.