I have some hollow section steel beams that I want to paint. They are covered in black greasy substance that I think is black oxide and oil. I can degrease it, but do I need to remove the oxide? I've tried to google this, but all i find is the description of what this oxide is and its purpose.
Do I need to remove the oxide coating from steel before painting
metalpaint
Best Answer
Red or black oxide is essentially a primer. It does help prevent rust a bit in the short term. I'd degrease, sand a bit if needed, re-prime, and paint. No need to strip the steel bare.