Try as you might to keep a sparkling clean look, your bathtub will eventually start to show signs of its age. Rust will peek through on cast iron tubs, while fiberglass tubs will be susceptible to discoloration, pitting, and scratches. Depending on when your bathroom was last updated, the tub may also be a less than appealing color.

Replacing the entire bathtub can be a difficult and costly proposition. Another option for sprucing up the tub's appearance is to give it a coat of paint.

You should first decide whether you want to hire a professional for the job or do the work on your own. Tara Mastroeni, writing for the National Association of Realtors, says the cost of a professional painting job will put you out several hundred dollars. However, it can be worth the price, since failing to prepare the tub properly can cause the paint to start peeling or chipping in no time.

If you want to do the work on your own, you can start by preparing the bathtub. Scrape out any caulk lining the tub, and make sure the gap that is left is thoroughly dried. You can also choose to remove the drain and any other fixtures in the area you will be painting. If you want to leave these in place, you should place painter's tape around them. Painter's tape should also be placed wherever you need to protect surrounding areas, such as the area where the floor and tub meet.

It is essential to give your bathtub a thorough cleaning. Jennifer Noonan, writing for the home improvement professional Bob Vila, says you should wipe down the surfaces with a solution of 10 percent bleach and 90 percent water. Rinsing between each application, you can then scrub the bathtub with an abrasive cleaner and a solvent such as acetone.

Locate any large scratches, chips, or other flaws. These should be patched with an epoxy compound and sanded down.

Once these areas have been repaired, you should lightly sand the entire tub. Mastroeni recommends using a 400- to 600-grit wet-dry sandpaper for the job. By roughening the surface, you'll make it easier for the paint to adhere. The bathtub should then be rinsed again to remove any dust.

Before painting, you should make sure the bathtub is completely dry. You'll also want to keep the room well-ventilated and use protective equipment, such as gloves and an air mask.

You shouldn't try to apply regular oil- or latex-based paint to the surface. You'll need to use an epoxy paint for the best result. Ace Paints, a Pittsburgh business, says kits are available to provide this material as well as other supplies for painting a bathtub. Many epoxy paints will require you to mix two parts together.

Depending on the paint you use, you may have to apply it using a spray gun, brush, or roller. Noonan says you should start in one of the tub's top corners, painting one side before working toward the other to apply an even, thin coat. Don't worry too much about any bubbles or brush marks, as these will even out as the paint dries. Mastroeni says you should complete the interior before working on the exterior to avoid contact with curing paint on the exterior.

Allow this first coat to dry completely. You can then add a second coat.

The paint needs plenty of time to cure, so avoid using the bathtub for several hours. Ace Paints suggests that you should not take a shower or bath for at least 36 hours after application. The paint's manufacturer should also provide a recommendation for drying time.

Once the paint has cured, you can restore it to its former state. Noonan says you'll need to remove the painter's tape, reinstall any fixtures you removed, and put down a new bead of caulk.

You may need to adjust your bathroom cleaning habits after painting the bathtub. Mastroeni says you should only use nonabrasive cleaners on the newly applied surface. You'll also need to be careful to avoid dropping heavy items in the tub, as the impact can cause the paint to chip.