Since I didn’t use the Skybolt flanges, I needed to drill out both the cowl and the custom built flange holes that I’ve been cleco’ing so far for holding the cowl in position. I used a step drill to take a section of holes out to 15/32″, removed the cowl, and drilled the flange holes further to provide enough clearance for the retainers. A tapered hand reamer is handy for touching up the 15/32″ cowl holes slightly to fit the rings.
I used floating retainers for the lowest position on each side. These allow a bit of up/down movement, not sure they were necessary but I put them in anyway as they were part of the kit.
While waiting for the 3D printed inlet plenum, I went back to complete a few cowling jobs.
The hole that I cut out of the lower cowling to clear the A/C compressor needed to be filled in. To do this, I taped a 1/4″ thick cardboard spacer in front of the A/C compressor, then applied play-doh to build up a shape that looked aerodynamically reasonable. I applied more masking tape over this, and then packing tape to act as a release agent. I then took the bottom cowling off, and applied two layers of fiberglass cloth over the taped off area. Once this cured, I pried it off, trimmed the excess, and scuffed the resulting shape all over.
After removing the tape and packing, I epoxy’d and cleco’d the shape piece in place, turned the cowl over, applied thickened epoxy to fill the gaps around the cutout, and then applied two layers of glass cloth over the entire inner area. Once cured, I applied a layer of micro to the outside, and sanded it back to form the final shape. There were a lot of crater sized pin holes and these will have to be filled, apart from this the A/C compressor bump on the lower cowling is done.
I also did the oil door. I stiffened the door with a piece of 0.063″ Alclad, bent into shape by hitting it with a rubber mallet. In retrospect, I should have either drilled some lightening holes in it or perhaps 0.032″ would have been OK, the door is quite heavy. I used a pair of Cessna KM610-64 Camloc’s for the catch, building up the button area with thickened epoxy to match the oil door thickness.
I also fitted the Aerosport RV-10 emblem covers to the cowling halves. Just follow the instructions, being careful not to epoxy the cowl halves together anywhere except where you intend to.
Taped 1/4" cardboard spacer in front of A/C compressor
Essential materials
Building up the shape
Taped up with packing tape
Two layers of glass cloth
Trimmed shape in place
Applied two layers of glass cloth to inside cutout
After one round of micro, needs more work
Oil door and stiffener plate
Alclad plate to stiffen oil door
Setting stiffener plate in place
After epoxy set
Drilling oil door hinge
Drilling holes for release catches
Release catch buttons built up with thickened epoxy
Release catches in place, roughly sanded
Release catches in place, roughly sanded
Stainless steel catch plates in place
Almost completed oil door
Glassing in Aerosport templates
After curing, with holes drilled and template punched out
