Even a tiny scratch can mar the appearance of an otherwise pristine enameled metal bathtub. Fortunately, repairing small blemishes and minor damage to your tub is not difficult, requiring a few products available at home improvement stores.
Removing Rust From Enamel
If your tub is marked by surface rust that hasn't penetrated the enamel or damaged the metal underneath, the fix may be as simple as using a cleaning agent to remove the rust staining. Try a cleaning agent with oxalic acid. Or try a mixture of salt and lemon juice applied to the rust. Leave it to sit for a day. This should take care of many rust problems.
More stubborn rusty areas may require treatment with diluted ammonia — 2 tablespoons in 4 cups of water — or a commercial rust-removal product. Bleach can make the problem worse, so you should never use it to remove rust from your tub.
Covering Chips and Scratches
You can also try a layer of baking soda to remove light scratches. Buff with a wet sponge for about three minutes and rinse. You may have to try this a couple of times. Or use a fine pore pumice stone. soak it in water, and run the stone over the scratch for about 30 seconds. Press down lightly with the stone. Wipe away powder and excess liquid to see your results.
If the scratches are a bit deeper, minor chips and scratches in your tub's enamel surface can be covered with a touch-up glaze. Touch-up kits with glazes are made to match your tub's surface color.
When using a touch-up glaze, clean the area around the scratch thoroughly with soap and water. When the area is dry, apply this glaze with a thin brush. Once the glaze is applied, let it dry for 24 hours; repeat the application as often as necessary to fill the scratch. After the glaze is dry, use the kit's fine sandpaper to lightly sand the area, then finish the repair by buffing it with a soft cloth.
Repairing Enamel Cracks
Deeper chips or cracks that penetrate the enamel and expose the underlying metal may require more substantial treatment with a repair kit that includes an epoxy resin. After you clean and dry the area around the crack, sand the area so the edges of the chip or crack are completely smooth.
Prepare the epoxy and fill the crack, getting the surface of the repair as smooth as possible. Apply second and third layers as needed. After the epoxy sets, sand it smooth, and buff it, then apply a finishing glaze to match the surface of your tub.
Enamel Tub Refinishing
If the enamel surface of your tub is severely damaged or worn over a wide area, the best option may be to refinish the entire tub. Although tub refinishing is significantly cheaper than buying a new tub, it requires extensive surface preparation and the use of toxic chemicals, as well as specialized skills and experience; it's not a do-it-yourself project.
Evan Gillespie grew up working in his family's hardware and home-improvement business and is an experienced gardener. He has been writing on home, garden and design topics since 1996. His work has appeared in the South Bend Tribune, the Fort Wayne Journal-Gazette, Arts Everywhere magazine and many other publications.