Price of copper tubing!

My shop was built in 92. I used galvanized. It was free and I had a power threader. I heard Copper explodes at the seam. I have never been in a shop with copper. Ours shop has 120 constant air to the drops. One thing I can tell you is when draining the drops the water is brown with iron pipes. The new shop will also have galvanized . Its cheap and Hit it with a piece of equipment like the fork lift it stays safe. Have a long nipple on the drop and you can hang the hose. I just feel safer with iron.

You are right about the flakes though. They make the seals leak on the couplers after a while.