415-C o 415-D Conversion

Good point! This might be a lot easier if I wait until the Cherry-Max rivet factory is back up and running.

Either that, or wait until I'm happy about the idea of taking the nose tank out. Having removed the control column twice in a year, I'm not in a rush to make it three. This is probably the way I'll end up going since I also don't love the idea of drilling out a bunch of rivets while the fuel tank is in place. 

I'll stick my head down there and see what the rivet access looks like. Thanks for the info!!!

Mine was modified back in the 60's, but it looks like what you describe. There are two layers of sheet metal over the fuel tank, the original AL with a SS over the top of that. I would imagine it took two people to rivet the new SS sheet, one outside running the rivet gun, and one inside bucking. It looks like they kept the original rivet spacing. They probably had to shift the fuel tank to reach/buck the rivets along the top of the fire wall. No Cherry-Max rivets in those days.

Recent discussion about gross weight increase STCs has me thinking about the C-to-D upgrade. As a sport pilot, until MOSAIC my only option was the Alpha Aviation 1320 pound STC. But now I could do the C-to-D conversion without locking myself out of the plane.

So, looking at EIL-1, it seems like I already have most of the prerequisites, but one of the steps is still not clear to me: To add the new 415-31245-5 (stainless?) skin on top of the nose tank. Has anyone done this? I haven't found any specific instructions online.

• Am I correct thinking that this new skin riveted on top of the existing skin?
• Are the existing rivet locations drilled out and reused?
• How difficult is it to reach all of the inside rivet holes to buck the new rivets?

Sure, I'll be left with an unpainted panel. My paint job is far from perfect and someday I'd love to strip and repaint the entire metal exterior - for now I could just paint it black and call it a clever anti-glare modification!