QOur bathtub faucet is about 25 years old, but it is in very good condition. However, it has a hard, white deposit built up at the outlet. How can we remove the deposit? -- P. Drake

AMake a solution of one part white vinegar to four parts water. Half a cup should be enough. Put some of the solution in a plastic sandwich bag and tie it over the faucet spout so the white deposit is immersed in the vinegar. Leave this in place for several hours or, if necessary, overnight. The vinegar will soften or dissolve the deposit, which is a calcium compound from hard water. Remove the bag and you should be able to pick off any residue with the tip of a knife.

This is also a way to clean out clogged shower heads without removing them. Tie on the bag as described; after removing it, use a sharp toothpick to clean out the holes of the shower head.

Faucet aerators can also become clogged with minerals from hard water, slowing down the water flow. It is best to remove a clogged aerator to clean it. Screw the aerator out of the faucet tip and disassemble it, noting how the parts fit together. Soak everything in a cup of vinegar solution. When all parts are clean, reassemble the aerator and screw it back into the faucet.

We recently had a front porch built of pressure-treated wood. The wood was primed and painted, but we have had a lot of stains bleeding through the paint on some of the posts. More paint doesn't stop the bleeding. Can you help? -- Brenda T.

Pressure-treated wood is difficult to paint, especially if the paint is applied soon after the wood is bought. Treated wood often contains a large amount of moisture, which can cause paint to peel or flake. The bleeding you describe is probably also caused by moisture seeping out of the wood.

Many painters recommend waiting three to six months before painting treated wood. This gives it a chance to dry out and reduces the chance of problems. In your case, my advice is to wait at least three months and then scrape off any loose paint. Wash the wood with a deck cleaner or detergent solution, rinse, and allow to dry again for a few days. Prime bare wood and stained areas with a stain-killer primer such as Bulls Eye 1-2-3, which is sold at many paint stores and home centers. Then apply high-quality acrylic-latex paint.

Our water heater produces a strong odor of hydrogen sulfide gas -- it smells like rotten eggs. The rest of the water system seems fine. We've tried a couple of things, but nothing has worked for long. Any suggestions? -- Ron

Some electric water heaters contain an anode rod, not to be confused with the electrodes, which heat the water. The anode, in combination with bacteria in the hot-water system, can cause the odor you describe. The anode is generally a magnesium rod that gradually dissolves. Its purpose is to help prevent corrosion in the tank walls.

Check your owner's manual to see if your water heater has an anode. If it does, you can have it removed and replaced with an aluminum-alloy rod that will not react with the water. It might also be necessary to add chlorine bleach to the tank to kill the bacteria (one cup of bleach per five gallons of water). Replacing an anode is tricky and, unless your manual gives specific instructions, the work should be done by a plumber. The bleach can be added through the hole in the top of the tank where the anode rod screws in.

This solution should be considered only if the odor problem is confined to the hot-water system.

What is the minimum size air compressor needed for a framing nailer in gallons, cubic feet per minute and so forth? -- A. Mercurio

In general, the minimum tank size for nailing guns and staplers is two gallons and the air requirement is one to four cubic feet per minute at 90 pounds per square inch. If you are shopping for an air compressor, though, this isn't the best way to go about it. A small tank is easy to lift and move around, but if you should want to use a spray gun, for example, you will need a larger tank (20 gallons) and more cubic feet per minute. The best rule of thumb is to consider all the tools you might want to use and to buy a compressor with the tank size and cubic feet per minute that will handle them.

Your dealer should be able to help you pick a compressor with adequate power, and an excellent source of information is the Web site www.aircompressorsdirect.com.

Questions and comments should be sent to Gene Austin, 1730 Blue Bell Pike, Blue Bell, Pa. 19422. Send e-mail to doit861@aol.com. Questions cannot be answered personally.