Tortoise

Hi all I'm very new to this and am just finding my way around. I have a large steel pipe fence that I want to use and cut up. The problem is is that on the inside of the pipes (the outside is painted) are dark grey and show barely any corrosion, just little flecks of rust. Anyway I have read about the fume fevers you can get when working with this stuff and I want to be as safe as possible when it comes to that. How can I tell if this is coated with zinc or not? I can't really get in there to look since it's a 2" wide pipe, nor can I file it off. Sorry if this is comes off as a dumb question, but I really want to begin without getting sick from fumes. I can't wait to join your forum also, it looks like a great place :)