Marketing, Advertisting & Communication in Iowa

I seen a company that makes little branding irons for your steak. I bought one and realized how simple it was. They cost about $50. I know I can tack one together but my questions is since you will be using it on food, what should I coat it with after I weld it together so the metal doesn't oxidize? When I bought their product it had some kind of a dull silver looking color.

If you are making it yourself from steel, after it is assembled, heat it to dull red or less and dip it in cooking oil. This will make it black and embed carbon in the surface which makes it mostly rust resistant - similar to seasoning a cast iron pan.