Rust stains in tubs and sinks can come from iron in water, a metal can, corroding hardware, or damaged finish. Before scrubbing, identify the material: vitreous china, enamel, acrylic, stone, and stainless steel tolerate different products. Start with the least aggressive compatible method and correct the source if staining returns.
Identify the surface before choosing a cleaner
Check manufacturer guidance if you are unsure whether the surface is acrylic, enamel, or stone. An acid or abrasive that works on porcelain can dull, scratch, or etch another material. Always test in an inconspicuous area.
Start with dwell time and gentle friction
Apply a compatible rust remover or cleaner according to its label, allow only the permitted dwell time, and work with a non-abrasive cloth or pad. Do not combine products in an attempt to speed the reaction.
Rinse thoroughly and dry before judging the result
Cleaner residue can continue reacting or leave film. Rinse thoroughly when the label directs, dry, and reassess. Several gentle passes are preferable to one aggressive attempt that damages the finish.
Recurring stains mean look for iron or corrosion
If staining returns beneath a faucet, inspect hardware and leaks. If it appears on many fixtures, iron in the water may be involved. A spot where the finish is chipped can rust from the base metal and may need repair rather than more cleaning.
Sources
- American Cleaning Institute — Cleaning Tips — General cleaning practices and product use according to labels and surfaces.