my english is not very good, but I will try to explain

buy clear packin tape aproximatly one inche wide, not that you can also find a tape especialy designed for that in your LHS

-cover and hinge your surfaces permantly
-deflect the surface to the maximum and find a way to block it in that position
-apply the tape with half sticking to the control surface and the other half sticking on the fix surface, be sure that your tape also stick in the edge between the surfaces, all the lenght of the flight control



for planes like a somethin extra I suggest to seal only on one side to keep the things easy


this is a frustrating job, but what I like in that method is that if you miss it, simply remove the tape and try again.......