Thats easy use what ever you covered the plane with. Or you can use clear Monokote. Cut a strip as wide as you need 1/2 or 3/4 inch and as long as needed. Iron the strip on the bottom of the wing or stab 1/4 inch bend the flying surface up iron on back of TE in gap then onto flying surface LE then onto bottom of flying surface. when finished it will look like a upside down V with two flat legs. Do that to all hinge gaps. Takes two minutes and your done