I agree with all of the above. Vinegar is acid, so sure it will clean metal, but if not neutralized, it will be a problem down the road. Phosphoric acid is one of the few exceptions and thus you see it as the main ingredient in most pre-paint metal prep products.
It was hard for me to locate phosphoric acid in bulk. I eventually was able to get an industrial dishwashing detergent company to sell me a gallon. Phosphoric acid is an ingredient in their commercial dishwashing detergents. I recall it is about 85% acid by volume. Good stuff. I haven't used it often, but plan to wipe down the interior of my doors as it is nearly impossible to media blast and/or paint properly. Haven't decided yet, but will maybe wipe on a paint of some sort as well. I can get my hand/arm in the door, but not any spray equipment.
Last edited by DavidF; 10/07/2013 3:16 PM.
