I am planning to install 0.025" 2024 aluminum for interior side panels in the cabin of the airplane.
I like this better than fabric from a durability standpoint. And I think it will give people who fly with me, who aren't normally used to flying in small planes, more comfort when they reach out and touch the walls of the cabin than they would get with a fabric-covered interior. I know others will argue about the weight penalty - but this is the only area where I'm planning to add weight beyond the "standard" design.
That said, I need an efficient and flexible way to attach the panels to the tubes of the fuselage without having to weld on tabs. What I have decided to try is to use AN742 plain tube clamps with Rivnuts. The first one I tried was a little tricky - you have to have the clamp tabs squeezed together pretty tight before you pull the rivnut. Otherwise, the rivnut will flare between the tabs of the clamp. I modified a side-clamping cleco to make it thin enough to clear the hole in the plain clamp's tabs so I can get the rivnut in.
I have installed two for trial purposes - and they seem to work very well. They are not so tight you can't move them at all - but they are snug enough to stay in place, especially while the panels are being mounted. I think with improved technique they be plenty tight for this application.
I plan to use rivnuts sized for 8-32 machine screws to attach the panels - these are NAS1329A08-120 aluminum rivnuts. The A8-120 has a grip range of 0.075 - 0.120". The AN742-D12 (3/4") clamp is 0.050" thick so these work well. The -D10 and -D8 are 0.032" thick, so I'll use the A8-75's which have a 0.010 - 0.075" range. I'll put in a dab of lock-tite or something to keep the screws from vibrating out since I'm not using nut plates.
