Antique cast-iron claw foot bathtubs originally matched the rest of the bathroom decor Only the outside of the tub was painted; the inside was finished with a baked-on enamel coating. As these tubs grow in popularity for modern bathroom remodelling projects, the art of painting and decorating them is once again gaining prominence. Surface preparation and quality primer and paint are the keys to success in your cast-iron bath repainting project.
Remove any rust from the outside of the tub with rust remover. Follow the manufacturer's directions for use and clean the product off with disposable rags when finished.
Sand the surface with an electric sander and 80-grit sandpaper. Alternately, have the bathtub professionally sandblasted, though that will require transporting the tub to the shop and back.
Wipe the tub with a rag dipped in white spirit to remove grease and dust. Wear protective gloves to minimise skin contact with the solvent. Allow the tub to dry completely.
Brush on a coating of latex- or oil-based metal primer. Use a high-quality, soft-bristled paint brush for an even finish. Let the primer dry thoroughly according to the manufacturer's directions.
Apply an oil-based undercoat and let it dry. Sand the undercoat lightly with 120-grit sandpaper to achieve a smooth finish.
Paint the tub with a top coat of good-quality gloss or semigloss house paint or automotive paint in the colour of your choice. Customise the finish, applying stencils in a complementary paint colour, if desired. Painting the legs of the tub with a contrasting colour or faux metallic finish adds visual interest.
Use enamel repair products to refinish an old bathtub's interior, if necessary. Don't paint the inside of the tub.
It was common to paint old tubs with lead-based paint, so have any old paint professionally removed. Scraping or sanding the old paint at home may result in dangerous lead exposure.