Carlos, I made the form with modeling clay. I had to make a support for the clay and made a crude fiberglass layup on a semi fitted form of foam sheet and plastic to cover the open fuselage area between the stabilizers. This fiberglass form was taped in place and lots of clay was put down on it and then the clay was scraped into shape with a long straight edge ( my 4 ft aluminum measuring stick.) Once the clay closely followed the turtledeck line, I laid down some plastic tape on the clay then brushed PVA mold release onto the tape. The clay also formed the radius around and under the stabilizers. This was not taped but brushed with PVA.
Some West 407 fairing filler was brushed onto the form before the cloth so there would be no place for air to be trapped and make a smooth surface to be in contact with the airplane. The layup was two plies of 6 oz. BID carbon for the main fuselage area ( because I had some scrap and to make the large open area stiff.) S-glass tapes cut on the 45 were used on all edges and around the stabilizers. There are about five plies around the edges except for the turtledeck overlap. The last cloth layup was a very lightweight satin cloth which just soaks up the resin from below and helps cover the coarser weave underneath. More 407 filler is put on after the cloth is wetted out.
Once cured, it is removed, trimmed and sanded. More 407 and/or 410 filler is added and sanded until all is faired and no pin holes (yea, right.) Final sanding is with 400 grit then epoxy primed. Of course some pin holes will appear after priming. If just a few, which was my case on this one, I filled with automotive spot putty, sanded off excess and reprimed.
I have one screw with nutplate on each side under the stabilizer in front and one screw (all #6) on each side at the rear to hold on the fairing. My fairing is on the outside of the turtledeck (like my RV6) and not underneath like a Sonex.
That's about all there is to it.
Rick Caldwell
Xenos 0057
- Clay modeling form
- Carbon wet layup
- S-glass wet layup
- Going with the filler and sanding process
- Test fit