We have a 20-year-old blue porcelain tub which has light brown stains and soap stains giving tub a mottled look. We have tried cleaning with some cleansers to no avail. We have some Gel-Gloss to use after but cannot figure out what to use to get out the stains.
The best product to use to clean old enameled and porcelain bathtubs is toilet bowl cleaner. Two good brands available are by Watkins Products and Home Hardware. Follow the simple instructions for cleaning and rinsing. After cleaning refinish with Gel Gloss all purpose cleaner polish.