Originally Posted by
cub builder
I've done upside down wet layups with fiberglass and carbon fiber. It's not easy or fun as gravity is always there and this stuff wants to fall off. If you have little composite experience, it's going to be a very frustrating, messy experience. About the only way to accomplish a wet layup while fighting gravity is using the plastic wrap method. I've had some moderate success with this method, but isn't something I'm anxious to do again. It would be easier if you made a jig to hold the piece in the shape you want, then use it as a mold to fabricate a new piece working right side up on a bench. Then it's easy!
One thing I didn't see in your post was what grade and hardness aluminum was used to construct the existing part. Study your aluminums and hardness for forming to what you need. More than likely the existing panel is 2024-T3. Look into 6061 aluminum and the various hardnesses available and their forming qualities. There are a lot of different Aluminum alloys and most are available in various hardnesses. Each one has different working qualities for stiffness, formability, and resistance to cracking. That doesn't look like a difficult piece to form. You could form it from dead soft material, then use that as a form to do a composite layup on the bench.