The post below on shop airline made me wonder why hardly anyone suggested galvanized pipe for shop air lines? I know there is a lot of hype on the internet about how the zinc will come off and contaminate air tools and actuators etc, but by my experience I have only seen one case where a galvanized fitting caused any issue, and it was a fitting that had an abnormal amount of zinc built up and restricted air flow not the pipe itself. We have been using Galvanized pipe both in our 65000 square foot fab shop, and in 95% of our sawmill installations for over 40 years with one complaint! I would hazard a guess that we have ran enough galvanized pipe for airlines to stretch from coast to coast. Recently a customer has requested we use black pipe. I think because of what he has read on the internet, not because of problems, but not sure. I cant see where black pipe would be better as it is definitely going to corrode faster. Maybe pickled and oiled would be better but this can get expensive. Just wanting to get opinions and experiences of YT people as I know there is a vast amount of real world knowledge on this site.