Pin covers finished, on to other cowl things

We rejoin the fun times from Sunday morning, where I went straight to work on all that micro I laid up around the pin covers. Unfortunately, my electrical tape trick didn’t work out perfectly – the tape ended up sliding off the edge of the pin covers in a couple spots. As a result I had no gap at all towards the aft end of both covers. The plus side is that since micro is way easier to sand than epoxy and glass, this wasn’t a huge problem. After the initial contour sanding, I went to work slipping sandpaper around the cover edges to clean up and open up the gaps as needed.

The resulting gaps aren’t what I’d call “perfect,” but this time I really am satisfied leaving it alone:

Looking at it from an oblique angle, the covers line up much more nicely with the cowl curve thanks to the contour sanding, though again the aft end of the right side cover is a little proud…oh well:

The next task will be the oil door. I pulled the upper cowl again, but before getting to the door, I finally took the time to sand the rivet line at the firewall edge. This is harder work than messing with the covers, but at least it’s not finicky. Basically I just go to town with 40-grit until the area is relatively level, then follow up with 100 grit on a soft block to smooth out the scratches.

I also went ahead and did a first round of scuffing on the perimeter of the oil door opening. The finish here was kind of crappy to begin with, especially the edges of the recess for the door, so I fully intend to reform this whole area with filler as part of the oil door fitting process. The micro needs a rough surface to adhere to, plus I want to sand the existing recess edges back to a bit of a bevel, kind of like I did with the pin cover openings. I’ll still want to do more work on that bevel, but this is a start:

For Monday’s work session, I did some more detail work. While I’d refined the paint gaps along the sides of the cowl and the cheeks, the spinner joint was still way too tight. So I joined the halves on the bench and spent about half an hour working on those until I had a nice gap in place:

Then it was on to the door itself. The door is provided as a prefab fiberglass unit, but it’s oversize and needs to be trimmed down. There are scribe lines on the door as trim guides, but upon close inspection they’re not perfectly straight, nor are they even. So while I used them as rough guides, in the end I put in my own work to properly squares up the trimmed door. Here’s the door before trimming:

My approach was to first rough cut one of the curved sides, sand it roughly straight, and then fine-tune it. For the fine-tuning, I glued sandpaper to a piece of aluminum angle; resting the door and the angle on the table made it easy to gently sand a very straight and very square edge.

One that was done, I used a square to lay out the other three cut lines, and repeated the process of rough cutting and then sanding to exact shape. Finally, I traced out radii for the rounded corners I wanted, and hand sanded those to shape. My cuts ended up a bit outside the scribe lines in some spots, so I also hit the perimeter of the door with 100-grit on a soft block to smooth things out a bit.

Here’s the trimmed door sitting in the cowl cutout:

The next question will be how I want to locate and fix the door in place on the cowl while I do the hinge and latch fitment. I might just end up drilling a few perimeter holes where I can cleco it in place, but I’ll want to think on that a bit. Food for thought while I wait for my parts from Spruce to come in.

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