Skinning using Interior Ceiling Panels?

[TAOLIK]

Hi All,

So due to some procurement related delays I've found myself getting a reasonably large beautiful dual pane RV window off ebay to replace my drivers window. As a result I need to skin over one final window. I am planning to use blind rivets instead of solid rivets because I'm lazy and don't want to recruit a bucker.

I have plenty of square footage in 18 gauge galvannealed scrap but unfortunately none of it is large enough.

I did notice that I have most of my interior ceiling panels which are maybe 22 gauge? These are plenty large to cover over my drivers side window. I've left them outside to smother some blackberry bushes for a a year or two but they are mostly rust free.

Ultimately the final product will only leave 1-2 inches on each side, and about 3-7 inches on the top and bottom after the window is in it.

I'm currently debating between using this thin gauge ceiling panel or just layering my 18 gauge metal over each other at the seams. Does anyone have an opinion regarding this? I figure if there's no rust I'm probably okay skinning a small space with the ceiling panel.

Thanks in advance for your expertise!