Primarily Petroliana Shop Talk Forums Shop Talk Petroliana Forums General Petroliana Discussion Like a milk jug but has gulf refining co on it??

Easy way to tell if it's dairy vs. oil:
Stainless steel or heavy tinplate = milk or cream
Anything else (copper, iron, aluminum, galvanized) = possibly oil

The oldest milk cans were tinplate to protect any stray iron or copper from oxidizing the milk. Those are often painted with a number which belongs to the farmer. The stainless steel is a high quality and may be stamped 3A or marked with a manufacturer's name or a dairy name. That said, I have a brass tag from a local dairy which was used to mark the cans which met its standards.