Our kitchen cabinets are stained and finished with polyurethane. Can we paint them without sanding? Will a stain-killer primer over the polyurethane suffice? — R. Valerio

Polyurethane generally has a glossy finish, and paint won’t stick to glossy surfaces unless given special treatment. There are several ways to do it, but one of the simplest is to use a glossy-surface primer. You can buy good glossy-surface primers at almost any paint store under various brand names. One popular choice is Zinsser’s Bulls-Eye 1-2-3. Zinsser also makes a relatively new primer, Smart Prime, which is said to be superior for glossy surfaces. Smart Prime is water-based and has low odor and low VOCs (volatile organic compounds), but is said to perform like an oil-based primer. Both Bulls-Eye 1-2-3 and Smart Prime are also stain blockers, meaning they will keep most stains from bleeding through finish paint. Before painting, be sure to clean the cabinets with a solution of household detergent and rinse.

We have a very noisy toilet in our master bath. The noise reverberates throughout the other rooms when the toilet is used. Any suggestions? — Bob

Toilets can make a wide variety of noises, ranging from hissing and groaning to foghorn sounds. You don’t give many details on your noise, but since it occurs when the toilet is used, it apparently is a flushing or refill noise. These noises are often caused by a defective refill valve, also called a ballcock. The refill valve is located inside the toilet tank on the left side. In many older toilets it has a rod attached with a metal or plastic ball on the end. The ball or float rides up and down, controlling the flow of water into the tank; it starts the toilet refilling after a flush and stops the water flow when the tank is full. In many newer toilets, the refill valve has a tower shape and the float rides up and down on the tower, performing the same function as the rod and ball. Replacement refill valves are not expensive (about $15 or less) and can be bought at many home centers and hardware stores.

Do-it-yourself installation is possible; usually the most difficult part of the job is removing the large nut that holds the refill valve in place. The nut is located under the tank, and removing it requires a large adjustable wrench. Care must be taken not to crack or chip the tank or bowl. Fluidmaster is a widely sold brand of replacement refill valve. Look for a valve that fits your brand of toilet and comes with instructions. Even if replacing the refill valve doesn’t completely solve your noise problem, it could help prevent future problems.

Is there any way to remove rust buildup around the rim of my bathroom sink drain?
— T. Crowatto

A product called Zud Heavy-Duty Cleanser, sold at many supermarkets and home centers, is excellent for removing rust stains from bathroom fixtures and some other surfaces. Zud is a powerful cleaner, and before using it you should read all the cautions and directions and follow them carefully.

Zud will also remove some other hard-water stains.

— McClatchy-Tribune

Questions and comments should be e-mailed to Gene Austin at gaus17@aol.com. Send regular mail for Gene Austin to 1730 Blue Bell Pike, Blue Bell, Pa. 19422.