Orval Fairbairn wrote:



Usually, they are made from a weldable alloy, NOT 2024 (24ST)!. 5052,
6061, 3004 in soft (non-heat treated) form are often used. Many cowls
are formed as sections and then welded together to form the final piece.

For many of those that are multipiece assemblies, you are correct. The
cowls for most of the birds that I have worked on were one piece
sections, with just mechanical fastner assembly. My L-5 has both types
of assemblies on it and my Fairchild cowlings were riveted stampings.

Craig C.