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…