Oil lamps provide light without electricity by using a wick to absorb lamp oil and carry it from the lamp tank through a brass burner into a glass chimney. Wicks eventually burn away and should be replaced with one of the same width that fits the oil lamp's burner. It's best to replace wicks before they burn out completely to ensure you'll have the light you need in an emergency.
Place the oil lamp on a flat surface that's covered with an old towel or absorbent rag. Be sure the lamp shade, chimney and all lamp parts are cool.
Remove the shade and chimney and set them aside. This exposes the oil lamp's brass burner that has a narrow slot through which the wick is threaded. The burner holds the wick in place.
Unscrew the burner from the brass collar to which it is attached. Turn the wick raiser knob forward to remove old wick that remains in the burner. The wick raiser is a small turning wheel attached to and extending from the oil lamp.
Slip the new wick into the burner from the bottom. When you feel the wick catch the burner teeth, turn the wick raiser knob forward until the new wick appears over the top of the slot in the burner. If you feed too much wick through the slot, turn the wick raiser backward slightly. Use scissors to turn the trim the wick until about 1/8 inch is exposed over the burner top.
Fill the oil lamp with lamp oil before replacing the burner. This allows the wick to absorb oil from the bottom. Use dry paper towels to wipe residue from all oil lamp parts.
Screw the burner back onto the collar. Wait at least 20 minutes before lighting the oil lamp.
Use hot, soapy water to wash the chimney free of soot. Use a lint-free towel to dry the chimney completely. Don't allow the chimney to become cold before you replace it. A sudden hot flame can shatter oil lamp chimney glass.
Touch the top of the exposed wick to be sure the wick has absorbed the oil. If the exposed wick is uneven, use scissors to trim it.
Light the exposed wick and adjust as needed to produce a low flame by turning the wick raiser. Replace the glass chimney and readjust the wick as needed to produce a low, steady, smokeless flame.