By Gene Austin Friday, February 25, 2011; 2:37 PM Q. I started trying to remove the cracked, discolored tile grout in my shower using a hand tool and think it will take at least 20 years to get it all out. Is there a better way? -E. Bartlett A. You can speed up the job by using a small handheld power device called a rotary tool, but it must be equipped with a special grout-removal bit. Rotary tools essentially contain a motor that spins a variety of bits and accessories at high speed. Corded and battery-powered models are available. The tools are often sold in kits with a lot of bits to drill, saw and grind, but the grout bit is seldom included. Manufacturers of the tools include Dremel, Craftsman (Sears and Kmart) and Ryobi. Some tools are priced at less than $100, and the grout bit at $20 to $40 more. The cost is still a lot less than having the grout removed professionally. You can check prices for the tools and bit at home centers or on the Internet, using a search engine and the words "Rotary Tools" and "Grout Removal Bits for Rotary Tools." Even if you use a power tool, you will still have to switch to your hand tool (a small grout saw works best) to clean out hard-to-access areas. Enough old grout should be removed to expose the unfinished edges of the tiles. Don't forget to spread a plastic sheet over the floor of the shower (or bathtub, if a tub wall is being cleaned) to keep bits of grout from getting in the drain. An alternative that I would seriously consider is to just cover up the old tiles with a fiberglass surround. These surrounds, also available for tubs, are attractive, durable and easy to keep clean, and the total price is quite reasonable, especially when a do-it-yourself installation is made. Some surrounds have built-in shelves for soap and accessories. Q. I own a property with vinyl siding that was never caulked around the windows. I was going to caulk them and was told never to caulk vinyl siding. Can you shed some light on this? -B. Segel A. Vinyl siding needs to be able to expand and contract with temperature changes, and it should not be glued down with caulk to prevent this. Vinyl siding that is installed too tightly can develop ripples and/or sagging. However, your vinyl siding should fit into metal or vinyl channels around windows and doors. These channels improve the appearance of the siding and allow it to move slightly. I know of no reason why you can't caulk the joint between the channels and window and door frames, which is where air infiltration and heat loss would occur anyway. Just don't caulk inside the channels where the ends of the siding fit. Q. We live in an 80-year-old building with cast-iron radiators. The radiators have been painted many times; most recently with acrylic-latex paint. The paint was applied when the radiators were cold and after the surface was scraped and cleaned. Now the paint is peeling again. What can we do to prevent this? -F. Heim A. If you want to have a first-class, lasting paint job, you will have to go to a considerable amount of trouble. Wait till the heating season is over and the boiler is turned off, then disconnect the radiators and take them outside. All the old paint should be removed. The best way to do this is to sandblast the radiators. This takes special equipment, and you should hire a professional painter to do it. Next, remove all dust from the metal with a vacuum or compressor air gun. The metal should then be primed with a rust-resistant primer. You can apply this with a brush, but it is tedious work. A sprayer is much faster and neater, so buy or rent an airless sprayer or use aerosol primer. When the primer is dry, spray on one or two coats of enamel. Acrylic enamel works fine if the radiators have been properly prepared. There is an option for those who want to save time and effort - radiator covers (also called radiator enclosures). These generally have to be custom made to fit your specific radiators, and they are available in metal or wood.