Re-enameling a bath involves scraping away old caulk, filling gouges with putty, sanding the entire tub and applying enamel with an airbrush. The process makes old baths look new for a fraction of the cost of a new tub. According to This Old House, re-enameling is a one-person job.
The first step in re-enameling a bath is to tape plastic sheeting over nearby surfaces, including floors and walls. Remove all faucet handles and the drain cover, sealing the holes with masking tape. After protecting the work area, use a putty knife to remove all of the old caulk on and around the bath.
Wearing protective gloves and a paper cone mask, pour rubbing alcohol over the tub and use a razor blade to remove stubborn soap or bath oil residue. Richard Weir, a writer for This Old House Magazine, also uses an alkaline cleanser during this step. Rinse the tub and dry it thoroughly.
Examine the tub carefully for scratches, gouges and chipped enamel. Using a thin putty knife or small trowel, spread fiberglass putty over these areas. Once it dries, use coarse sandpaper to smooth the surface, then switch to a finer grain to blend out the edges. Soak a clean rag in a porcelain bonding agent and rub it over the entire tub. As it dries, don a ventilator and protective clothing.
Apply two or three coats of spray enamel, waiting 15 minutes between each application. Let the final coat dry for one or two hours. Buff the enamel to a high shine.