Making the Tail Fairing Blocks
Shaping Tail Fairing Blocks had been a tricky process, up until I discovered the following method of making the blocks fit perfectly by using a simple sanding jig. The jig is made up from balsa of the appropriate thickness to fit the fuselage, and essentially replace the vertical and horizontal stabilizers during the shaping and sanding process.
The process begins with making the jig. Use balsa the same thickness as the vertical and horizontal stabilizers, cut to the shape of the stab saddle, and following the contour of the fuselage. The jig is then tack glued to the fuselage. Next, make up the fairing blocks from foam or balsa, cut to the rough shape of the jig. And finally, tack glue the blocks into the jig.
The next step is to carve the blocks to rough shape, then sand to final shape. At this point, the blocks are perfectly contoured to the fuselage shape, and are ready to be removed from the jig, and the jig removed from the fuselage. Scroll down for the step-by-step photos.......
The jig is built form the appropriate thickness of balsa based on the thickness of the stabilizers on your particular model. Some kit makers provide the parts to make the jig, otherwise, the parts shape can be pulled from the plans, or the fuselage assembly itself.
With the jig assembled, it is then fitted into the fuselage frame and tack glued in place
Using the jig, trace the shape of the block onto the foam or balsa stock and cut the blocks to rough shape.
Tack glue the rough shaped blocks into the jig.
Carve the block to rough shape, then sand to a smooth clean contour.
With both sides carved and sanded to shape, the blocks are ready to remove from the jig.
The finished blocks are carefully removed from the jig and the jig removed from the fuselage to finish up the shaping process. Now the finished blocks can be sealed up with a couple of coats of water based varnish to seal the wood or foam. After the first coat has dried completely, remove the surface fuzz with fine sandpaper and apply the second coat. Now the blocks are ready to cover or paint.
Now that the blocks are shaped, they'll fit perfectly on the fuselage when the tail section is glued in place. And as an added bonus, you can use the blocks to aid in the alignment of the tail-planes during final assembly.