Nice looking sets. The tub looks more like chemical damage than wear. I know if you put baking soda and some other powders too, as additives, it will attack the porcelain enamel on tubs. At the shirt laundry we used "sour", which eliminated the soap content in the rinse and that destroyed the porcelain on the tubs of washers too. I learned that by experience unfortunately. It made a washer tub like sandpaper first and then it removed the porcelain to the point of rusty metal underneath.[this post was last edited: 9/14/2017-11:57]