Any other Smith's out there have aluminum wing ribs? I am build a few new ones for mine. I measure the old, cracked ones and they were .038" thick. I went with .040 2024 Al, but they are extremely hard to form. The old ones don't seem to be that hard. Wondering if I should be using 6061 instead or go to thinner material. It's only the end rib that I need to replace. Thoughts?