The two piece fuselage has to be ready to accept the tail feathers by being temporarily set. I put the byrofoam collar in the front half of the fuse and pulled it back untill it was very tight. It was then marked with a pencil around where the edge of it was. It was then removed and that area that was inside the mark was sanded with 80 grit sandpaper. It was then installed using 15 minute epoxy. Only install the collar in the font half of the fuse!!!!
After the epoxy is cured, the aft fuselage piece is slid on. The tighter that this piece goes on, the better and tighter the seam. Mine turned out great. Then it is taped on for removal later when all of the internal things such as the retract mount, elevator horns etc are fed through and hooked up.