DEAR TIM: My husband and I are planning a bathroom remodel. We can't agree on which type of tub / shower stall to install. My husband says there is no substitute for cast iron. Because of the wide variety of shapes and sizes, the fiberglass and acrylic products appeal to me. My husband says these units won't stand the test of time and scratch easily. I mentioned that cast iron products can chip. Without your help, we may be headed for divorce court! A. G.

DEAR A. G.: I hope both of you have good attorneys. I think you might need them as both of you have raised some valid points. I'm very confident that there is a product or two available that will satisfy both of your desires.

Your husband's comments concerning cast iron are very accurate. Cast iron plumbing fixtures are extremely durable. Cast iron will not flex. The thick enamel coating is actually fused to the cast iron in high temperature ovens where the temperatures exceed 1,700 F. Through this process, the enamel achieves a hardness very near that of ordinary glass. However, enamel can be scratched and it does chip. If you don't believe me, come and look at my kitchen sink.

As you have already discovered, there are many manufacturers, styles, and materials used in fiberglass type tub and shower stall units. While the finish on these units is not as hard as enameled cast iron, they can easily retain their glossy appearance with a little care and maintenance. The simple rule is to use the same care and cleaning products that you might use when you wash your new car.

There are three primary types of "plastic" tub and shower units: gel-coated fiberglass, acrylic reinforced with fiberglass, and acrylic backed with a structural composite. Side by side, these products look very similar, however there are important differences.

The gel-coat products, when constructed with high quality ingredients, can be very hard and durable. The manufacturing process is critical, as the liquid gel-coat must be applied evenly on the molds at the correct temperature. Gel-coated products if damaged or scratched can be repaired with great success. Repairs performed correctly are permanent and virtually invisible.

Acrylic units are usually constructed using large sheets of solid colored acrylic plastic. These sheets are heated so that they soften. The softened sheets are then stretched over a mold to achieve the desired shape of the shower or tub unit. This stretching process, however, sometimes causes the acrylic to be very thin as it stretches around corners. Those units with the highest percent of acrylic tend to offer higher performance levels. Repairs to these units are not always successful.

Should you and you husband eventually agree on using a "plastic" unit, be sure to carefully follow the installation instructions. Many homeowners in the past were dissatisfied with the fact that the floors of these units flexed like oil cans. Some of the acrylic units backed with composites have addressed this problem. The other units often need to be set in wet plaster or mortar to provide a solid base. Be sure that you or your contractor carefully follows the installation instructions.

The care of either cast iron units or the alternatives is important. Never use cleansers that contain abrasives, as these can scratch both cast iron and plastic fixtures. If you simply make a practice of cleaning the tub or shower area every two weeks, you will avoid the heavy soap buildup that often necessitates heavy scrubbing. Virtually every manufacturer has a recommended cleaner that they strongly suggest you use. Follow these instructions and you will have a beautiful tub and shower area for many years.

Finally, if you do select one of the "plastic" units, you can keep it looking new with a little known trick. Once a month, take just fifteen minutes and apply a high quality spray automotive wax to the wall surfaces only. Never apply wax to the floor of the unit. Buff this wax out and it will be as shiny as new!