Hey all--
potentially noob question here. I've got all my mild steel tubing cut up for my brew stand, and I'm itching to start welding. But I recognize that any wort of paint prep is probably going to be a LOT easier to do before welding, leaving only a 'last wipe' before putting paint on.
Soooooo, here's my dilemma. The steel obviously has a greasy coat on it, understandably to protect it from oxidation/rust. When I looked around on how to remove it, immediately I found lots of talk about mill scale. Sure enough, there's a layer of tough, black material on the entire exterior of the steel; I had assumed that it would 'rub off' with the oil. I put some elbow grease into it, and a couple hours later, and 2 drills in thermal overload protection, I had gotten through stripping a whopping 15% of the steel down to shiny metal. Tops.
Sooo...I went back to the interwebs, and I found a few posts from guys that stated that most square tubing (mine is 2x2x 11ga) is already 'pickled' to removed the mill scale, and then oiled for protection. Consensus seems that painting over mill scale is NOT ok, but that painting pickled metal is.
What's the skinny, folks? Is this mill scale or a protective oxide layer formed by pickling? Either way, do I really need to remove it? I have removed all of the unknown material near any/all of the weld areas. I am planning a flat black VHT flameproof paint, should that matter.
Thanks in advance!
potentially noob question here. I've got all my mild steel tubing cut up for my brew stand, and I'm itching to start welding. But I recognize that any wort of paint prep is probably going to be a LOT easier to do before welding, leaving only a 'last wipe' before putting paint on.
Soooooo, here's my dilemma. The steel obviously has a greasy coat on it, understandably to protect it from oxidation/rust. When I looked around on how to remove it, immediately I found lots of talk about mill scale. Sure enough, there's a layer of tough, black material on the entire exterior of the steel; I had assumed that it would 'rub off' with the oil. I put some elbow grease into it, and a couple hours later, and 2 drills in thermal overload protection, I had gotten through stripping a whopping 15% of the steel down to shiny metal. Tops.
Sooo...I went back to the interwebs, and I found a few posts from guys that stated that most square tubing (mine is 2x2x 11ga) is already 'pickled' to removed the mill scale, and then oiled for protection. Consensus seems that painting over mill scale is NOT ok, but that painting pickled metal is.
What's the skinny, folks? Is this mill scale or a protective oxide layer formed by pickling? Either way, do I really need to remove it? I have removed all of the unknown material near any/all of the weld areas. I am planning a flat black VHT flameproof paint, should that matter.
Thanks in advance!