Let's just say a little birdie I know was pretty positive what type of material this was, didn't ask how he knew(LOL) but went with it. Went with a 150* preheat and 308 because I didn't have any 309 laying around. Guy I talked to while cleaning up I told him what type of metal it could be and said that maybe the guy running the drill didn't know what he was doing and he laughed(he was with the maintenance company) and said he knows the guy who tried to drill it and he knows how to run a drill but kept burning up bits. He could not figure out why they would have this heavy blast door and not 30 feet away have a regular steel door!! He laughed and said, "it just don't make sense!!".
Funny thing is welds I look at of mine and think, "I can do much better" and then these folks walk over and say things like, "That's money!!", "Those are excellent looking welds" I'm starting to wonder what the heck it is they've been looking at!! Thanks for the comment though Al, I keep on working on making the pretty welds!!