Joshua's RV-9A Project

Today’s goal: get the spraying started on the cowling.  To do that, first I needed to finish sanding the side hinge joint gaps.  Lots of on-off of the top cowl as I slowly whittled the gap open, then once it was close, used a thing sanding tool (paper glued to a thin metal strip) to create a straight, even gap.

Next up was addressing the forward baffle airseal.  I’ve tried a couple iterations of this and been unhappy, so this morning I saved a bunch of pictures of different builders’ solutions — not one the same, mind you.  With a concept in my head, I tried a couple things and settled on one that seems to work, matching up with the curves of the cowling and inlet ramps.  I still need to file the front of the baffle where I trimmed it, rivet these in place, and stitch together a couple of the overlapping “paddles” of airseal.  More on-off of the cowling as this process progressed.

Nextly, masked off the forward top skin — aka “boot cowl” — sanded, and cleaned it in prep for primer.  Took the cowls and spinner outside and gave them a thorough wash with Dawn and lots of water.  Covered up the canopy with plastic and the engine with a dropcloth.

Once the cowls were dry and wiped once more with a microfiber cloth, set up the sawhorses and plastic drape, and mixed up a batch of DPLF primer.  Sprayed the oil door, spinner, both cowls inside & out, top skin, and canopy fairing (again, because it had suffered several large scratches during installation).  Left that to dry while I ran to town to pick up some spot putty and topcoat paint.

Came back and attacked the remaining pinholes with fast-setting (20 min) spot putty.  Once dry, sanded off everything but the tiny bit inside the pinhole.  Resprayed DPLF over the sanded areas.  Tomorrow night–assuming I escape from work at a reasonable hour–the exterior of the fiberglass parts will be sprayed with K36.  The inside of the cowls will be sprayed with the paint I picked up, PPG Omni acrylic urethane, single-stage two-part.  This will seal up the surfaces against oil, and the white color will increase visibility under the cowl, and make leaks easy to spot.