One of the weakest points on a control surface appears to be where the horn attaches to/through the surface itself. A simple solution is to cut a hinge slot centrally into the control surface where the horn will attach itself. Put a mylar hinge in place and wick some CA in there on both sides  - make sure that the hole is not too big as this will be counter-productive! Wait for it to dry and then cut the hinge flush - job done. This can all be done before covering as well. Indeed this can be done on any surface that will need something bolted through near the edge!
Steve Jarman

This is quite a simple solution for getting the fuselage straight. No more sighting a line down the middle! Before you reach this stage, it is essential that you build the fuselage SQUARE using all the tools at your disposal.

One the two sides are glued together at the front two bulkheads, you will need to pinch the rear of the fuselage together and glue it - but how do you get this straight?

Rather than looking down the middle, drill a small hole on the firewall, dead centre and thread some black cotton through it and tie it to the firewall. Run this cotton down the length of the fuselage, and out the back. Hold the rear of the fuselage together, and the cotton will form the centre line (or thrust line).

Now move the two sides against each other and the centre line will move left and right - once you have found the centre position, this is the correct setup!

Now glue the two fuselage ends together with PVA, and repeat the above procedure - it will take all of 20 seconds. Pin them together, and you have a perfectly symmetrical fuselage! Now go and fit the decking…
Steve Jarman