Q Is there any way to remove a long scratch from a glass tabletop?

A To remove a light scratch from plain glass, use jeweler's rouge (ask at a jewelry store, or check with a jewelry supply store). Follow label directions so the glass isn't damaged further. Do not try this removal method on tinted and safety-glazed glass without consulting a professional.

If the scratch is deep, call a glass company, hardware or furniture store for advice. They may be able to treat the glass. They can also tell you if the scratch compromised the strength of the glass. The best solution, safer than covering the glass with a cloth, may be to replace it.

Placing CO alarms Q Can you settle a disagreement in our house? I say the CO detectors belong in the basement where the furnace and water heater are, but others in the house say they belong on the second floor where the bedrooms are. Who's right?

A Ideally, a house should have an alarm on each floor occupied by people, but if there's only one CO alarm, most authorities recommend it be placed near sleeping quarters. That's because you're more likely to be awakened if it sounds when you're sleeping and because people spend a lot of time in their bedrooms.

But CO alarms are only half the safety equation. You need to prevent the formation of CO in the first place. To do that, make sure all fuel-burning appliances are in good working order. Have the furnace/boiler and water heater serviced annually, and get the gas stove, fireplace and chimney checked regularly, too.

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies. Fixit appears every day except Friday.