I epoxied the new leading edge onto the tunnel. This is the underside. I left the front edge of the original cowling in place so that there will be a confined area for the intake. I'll then mold additional fiberglass to join the new ramp area to the original cowling and then funnel it to the carb intake via a carb heat box.

This is the first layer of filler. This is 3M Short Strand fiberglass filler. It's a 2-part system. It sands great, but you wouldn't want to use it as a final filler because it doesn't self-level or fill small voids very well. My normal process is to use this first and get the shape where I want it and then use SuperFil for the finish filling. This 3M stuff gets VERY hard. A few of my RV-building friends actually used this for their rudder tail light installation. They installed a big glob of it and then drilled and tapped it for a machine screw. Good stuff.

I thought I was done shaping the ramp when a friend stopped by and suggested that I should have a more shallow slope from the inlet towards the tunnel. I ended up using a popsicle stick to mold in a flat slope from the tangent of the underside of the lip of the intake.

Here's This was basically where I stopped with the heavy duty 3M filler. If you look closely, you can see where I was using some pretty coarse sandpaper that left definite lines in the filler and the fiberglass. I've also sanded aft a little bit to approximately where the original cowling remains. I'll finish the inside of the tunnel and spray paint it white before I join the new tunnel and inlet to the original cowling. There will be no way to do any of this once the new tunnel is glued to the original cowling. This is hard to describe so I'm hoping the next few pictures will make it easier to understand.

Well, I guess I missed taking a picture of the intermediate step showing the use of SuperFil. Prior to taking this picture, I applied a coat of SuperFil and then sanded with a little bit finer grit sandpaper... probably 160 grit or so. If this part were critical (or even if it was ever going to see the light of day again) I'd use progressively finer grits of sandpaper down to at least 320 grit before I started applying primer.

Once the 2-step filling process was complete, I used a rattle can grey primer as you see in the picture, here. Again, if this were a part that would be seen, I would have used a real filler-primer like DuroFil by Evercoat.

I guess this is about as close as I'm going to get in terms of a finished product for the inside of the intake scoop. This is just Rustoleum rattle can gloss black paint. This is the _inside_ of my intake scoop so it's not critical. My thought was that it'll be impossible to paint once it's bonded to the lower cowling because this part actually overlaps the part of the original cowing that wasn't removed. I just used black because I wanted people to just see a dark hole when they look in the intake smiley.

I went to the trouble of sanding and filling the part because I hate the look of unfinished fiberglass work!