Things You'll Need
Porcelain etch solution
Fine paint sprayer
Primer for porcelain
Clear-coat paint-polyurethane compound (for porcelain)
The initial shine of old bathtubs came from a baked-on coat of porcelain. This coat can wear down, dull and discolor over the years, leaving you with a bathtub that's perfectly functional but that looks terrible. One way you can restore that shiny coat yourself is to paint the tub — not with regular paint, but with specially formulated coatings that include polyurethane, the same hard, clear material that goes over wood floors to give them that glassy shine. See your refinishing dealer for the right tools and chemicals.
Use your screwdriver to remove the bath faucet, handles and other fixtures from the tub. Press masking tape over any fixtures that can't be removed. Spread plastic tarps over the floor and walls.
Put on your respirator, mask and gloves.
Brush etching solution over the porcelain surface of the tub, using your paintbrush. Cover the whole surface in a thick layer of it.
Let the solution etch the surface for 15 minutes. Rinse well.
Load your paint sprayer with primer. Spray it on in a thin, light layer. Keep the sprayer moving at all times to avoid drips or ridges.
Allow the primer set for four hours. Apply a second coat in the same manner. Let it set for 12 hours.
Fill the paint sprayer with clear-coat paint-polyurethane compound. Spray it in the same manner as before, in a thin, light coat. Let it dry for four hours.
Spray on a second coat of compound, let it dry, and repeat. Continue until you have sprayed on at least four coats, to the desired finish. Let the final coat set for two full days before reinstalling the fixtures.