Now that the top cowl and bottom cowl are held into postion by the back edges, its time to mate the horizontal edges. To do this, I started by sanding the bottom edge of the top cowl to make it completely flat and straight. I did this on my bench by running sandpaper between the cowl and the bench surface so as to sand the cowl edge. This caused only the high spots on the edge to be sanded. At the end of it, I knew that both edges were flat and well aligned to each other. I then attached the cowls to the fuselage with the top half overlapping the bottom half on the horizontal edge. I was then able to draw a line on the bottom half with a sharpie. I removed the bottom half and sanded the excess material off the bottom half top edge. This got the mating surfaces close, but not perfect. To get them just right, I forced a piece of 60 grit sandpaper between the halves in order to sand the bottom half to fit precisely. I ran the sandpaper up and down the seam until the sandpaper passed easily. This actually created a consistent .015 gap between the two halves all the way down the seam on both sides. This will help to keep the hinges from binding when complete. The pictures show the mating surface at the end of all of this.
