I added a couple of #8 nutplates to the inside faces of the cowl inlets.  The needed to be set forward of the aft edge about 1/2″ to clear the inlet seals.  You can also see that I used some epoxy/flox to fill the hole that I’ve been using to align the cowl up to now.  The plans specify three nutplates here, but the plans also don’t specify a plenum which results in substantially more force trying to separate the cowl halves.  With the plenum, there’s far less force trying to lift the upper cowl, so two nutplates should be just fine.

The upper and lower halves of the cowls don’t perfectly align at the outer edges of the inlets, so I mixed up some epoxy/micro and applied a fairly thick coat.  Most of this will get sanded off, but I’m pretty sure I’ll still have to add another coat.

Here’s the right inlet.  I managed to scrape away more on this side before the epoxy started to set up, but there will still be lots of sanding.

Where the upper and lower cowl halves meet on the outer ends of the inlets, the top and bottom sections simply butt together.  There is nothing tying the two parts of the cowl together at this point which allows some relative movement, and air entering through the gap is just added drag since it doesn’t help with engine cooling as it’s dumped directly into the low-pressure area outside the baffles.  To address this, I’m adding some flanges to the lower cowl that the upper cowl will nestle over.  This will reinforce this area a bit and seal the gap.  To prevent the epoxy from sticking to the upper cowl, I covered this area with electrical tape.  I would normally use packing tape, but it can’t conform to the curves like electrical tape can.

The lower cowl protruded beyond the upper cowl a small amount, so the glass wouldn’t have laid flat across the transition.  To fill in that step, I mixed up some epoxy/flox and made a small fillet.

I then laid up about 6 layers of glass across the joint.  I’ll trim this back quite a bit after it cures.  It really only needs to stick up into the upper cowl 1/2″ or so.

Here’s the other side.  You can see better here that the glass overlays the oval where the hinge pin covers will mount, so I’ll end up cutting back part of the flange to make room for the cover.

I popped the two cowl halves apart and was left with a pretty nice flange.  I trimmed this down to about 1/4″ above the lip of the cowl.

I then taped it up, mixed up some epoxy/flox and reassembled the cowl.  This will provide a structural extension to the flange of the upper cowl (were there was a tiny gap between the top and bottom halves) as well as provide a perfect fit between the flange and the inside of the upper cowl.

I popped the cowl apart from my filler application last night and this worked beautifully to make the flanges a perfect fit.

You can see here that it also allowed me to slightly extend the flange on the upper cowl to match up with the lower cowl.

Next up, I trimmed the upper and lower cowl flanges a bit and then wrapped the lower cowl flange with tape.  The electrical tape is there to define the line where the upper cowl flange should reach.  The packing tape is there to keep the epoxy from sticking to the lower cowl flange.

After assembling the cowl halves, I cleaned out the screw holes and punched a hole in the packing tape for the screw that aligns the two halves.  I waxed up the screw really well to keep the epoxy from sticking.

I then cleaned up the inside of the joint so there isn’t a bunch of excess epoxy here.

The fit on the propeller ring has always been pretty poor.  Now that the upper cowl flange is straight and is a perfect fit for the shape of the lower flange, I can fix the position of the lower flange step to line up with the upper flange.  I assembled the two halves with a piece of saran wrap sandwiched between and then stretched it back over the upper flange.

I then mixed up some epoxy/micro and filled in the gap.  After it cured, I rough shaped it with a vixen file.  I still need to build up the face of the propeller flange a bit near the joint, so there’s no sense in making this perfect now, but you can already seen how much nicer this looks.  While this was curing, I cut and laid out the holes on the gear leg fairing hinges.

After pulling off the board I used to create a flat ring around the spinner, I sanded it flat with a long sanding block and added a little more filler to fill in the small depressions left by some wrinkles in the saran wrap.  I also tightened up the gaps between the upper and lower cowl halves a bit.  I’m such a perfectionist, that this part of the construction is going quite a bit slower than I’d hoped.  All of this will be highly visible on the finished plane though, so it’s worth the extra time.

I had been planning on installing the wheel pants and gear leg fairings while the plane was on jacks, but I’m simply running out of room in my garage.  I needed to lay on the floor to align the left wheel pant, and I practically couldn’t do it.  I had really hoped to accomplish pretty much all the construction at home, but it looks like the gear fairings will have to wait until I’m at the hangar.

Anyway, I mixed up another coat of epoxy with microlight and built up a little bit more around the air inlets.  Here’s the upper cowl on the outside edge of the right inlet.  The electrical tape is preventing the filler from lapping over onto the lower cowl and will provide a nice reference when sanding this to shape.

I also applied a little more filler to the inside edges of the inlets to fill in a small step that I had.

Here’s the outside edge of the upper cowl next to the left air inlet.

I also sanded down the second coat of filler on the prop ring.  I still need to see how the gap looks with the prop on, but I’m pretty sure that the gap will be uniform all the way around.

I used a vixen file to rough shape all of the filler I applied a couple of days ago and then sanded everything until you can’t even feel the gap between the upper and lower cowl halves.  I’ll need to open the gap up slightly for paint, but the shape is nearly perfect.  Next, I started flattening the filler on the upper cowl.  I previously picked up this longer flexible sanding block from Harbor Freight.  It has a spring steel plate on the bottom which is flexible enough to conform to gentle curves, but flat enough to sand the surface and eliminate all the waves in the surface.