I had to purchase some square steel tubing today to finish a project. It's 2"X2" 11 gauge tubing. The place I was going to purchase it from sells the tubing already primed with red oxide primer, but they no longer sell the 11 gauge square tubing. So, I had to buy from a metal building manufacturer and all they have is oiled steel tubing.
How do I properly prepare this oily steel before priming and painting? I'll have to cut and weld it before priming of course. Brake cleaner spray?
What you guys say?