reprinted courtesy of ServiceMagic.com
This can help clarify and answer
some questions.
Sheetmetal comes in different thicknesses, from 16 gauge to 30 gauge, with lower numbers being thicker. Whatever is created can be made water tight or not. Seams can be sealed with sealent (caulking) or soldered. Soldering is more durable and a bit more expensive than sealent.
Copper will naturally change to a turquoise color after exposure to natural elements. The more salt and moisture in the air, the sooner it will change color. This does not damage or affect the strength/quality of the metal. It can be coated to retain its natural "shiny penny" color or combinations of different chemicals called "patinas" can be applied to immediately turn copper into a variety of different colors, including turquoise, red, black, blue, etc.
-- Tips courtesy of Service Magic