Refinishing a cast iron tub is a daunting task but attainable with the right amount of preparation and tools. While you may wish to go with a professional, by carefully following these instructions, we feel confident that you’ll be able to turn an old, dull tub into a brightly shining fixture in less than two hours.
Acid based commercial cleaner
Acid etching paste
Spray on primer
High gloss polyurethane
Air gun and compressor
What sort of tub do we recommend in the first place? The MTI Berceau. It’s gently sloped for comfort and finished with a durable yet smooth feel to it.
Put down a drop cloth, as some of the chemicals we’ll be working with can be corrosive to other surfaces in your bathroom.
Use your utility knife to slice the bottom of the caulk on the rim of the bathtub. Do your best to get as close as possible to the tub when making your cuts. Since the tub is about to be refinished, don’t be too concerned about nicking the tub.
Once you’ve cut all the way around the tub, use a straight edge razor to slice off the caulk from the tile above it. Clean out all of the debris from cutting out the caulk.
Bust our your glove and respirator at this point. Start ventilating your bathroom with a vent fan if there’s one installed, and open a window if possible. Also tape plastic over your spout, thermostat handles and remove the drain assembly.
Using the acid based commercial cleaner, spray down your tub and let sit for 10 minutes (or longer if the directions on the bottle recommend it). After the setting period is done, scrub with brush to remove as much staining and dirt as possible. Rinse with water. The acid in the cleaner will react with any mineral deposits which are usually
Tape plastic over your tile, so that you won’t get the acid etching paste on any of it.
Using your brush, cover your tub in the acid etching paste, so that every surface (including the outside of the tub) is covered with a thick layer. Wait 20 minutes for it to take effect, and then add a neutralizing agent before washing it out with water from your tub. Check for any remaining paste and then dry your tub. Double check again for any remaining bits of caulk or wet spots of paste or water.
Using the air gun, compressor and spray on primer, evenly coat your entire tub with the primer. After it’s dry, spray a second layer. While that dries, mix white paint and high gloss polyurethane on a fine mist setting. Allow 45 minutes in between each coat for drying, then do at least 3 more coats for a shiny, glossy finish.
24 hours later, reapply caulk where the tub meets the bottom edge of the tile. Use a dry, clean towel to wipe away the excess.