This is the beginnings of a decorative covering for a mess of metal that is a range hood.  It is constructed of 3/4" plywood ribs and covered with 1/8" bending plywood.  I used the scrap bending ply and added an additional layer in behind at the extreme curves to reinforce them as they are a bit weak.  I could have used more ribs, but didn't anticipate this problem and therefore did not have any available.  I think this extra layer was actually a better solution as it really took the flex out of the curves.

I ran into an unanticipated problem when assembling the frame structure.  I had cut 5 ribs all the same and when I went to install the outside corner ribs, they were way off.  So I called an engineer friend of mine and discussed it over the phone and he came up with a formula for me.  I made a graph of 2" squares on a big sheet of paper and then scribed one of the ribs onto the grid.  I then plotted the coordinates and used the formula to come up with the new coordinates for the corners.
 
 

There was some concern about what materials to use for the stucco to produce a French country type of look.  I asked around and decided that I needed something very flexible to go over the plywood and found a product which is used on the exterior of commercial buildings.  We call it "DRYVIT" in these parts.  There is a product which is used to bond the commonly used OSB substrate used in roofing so that the "DRYVIT" can be applied.  It is quite flexible it actually dries to a very dry gum.  There is a mesh which is set in place with this product to reinforce corners and joints.  Then the stucco is applied over it.

Once the stucco is applied, it can then be painted.  All the applied products are of an acrylic base, including the paint and caulk.