Things You Will Need
- Measuring tape
- Electric drill
- 1/8-inch drill bit
A wood stove depends on air to keep the fire burning and to move smoke and gases from the system and out through the chimney. While most stoves feature built-in dampers that regulate the amount of air the stove takes in, an extra damper in the stove pipe can be useful in situations where there is too much of a draft, as in an uninsulated room, garage or workshop.
A second damper also helps regulate the amount of air being used by a less efficient stove and keeps the stove pipe from getting too hot.
- Measure the length of the vertical section of the stovepipe in which you will install the damper.
- Mark the spot roughly halfway up the section.
- Measure the circumference of the pipe section, starting from the spot you marked and ending back at the spot.
- Divide this number by two, and measure from the starting point to this figure, which should be on the other side of the pipe directly opposite the first mark, and mark the second spot.
- Drill a hole through the pipe on each side where you made the marks, moving the drill in and out a few times to smooth the edges.
- Take the stove pipe apart, remove the section with the holes, and set it on newspaper to catch any soot and other debris.
- Twist the center rod of the damper to separate the two pieces.
- Insert the tip of the rod into the first hole you drilled, and lower the damper into the stove pipe.
- Insert the rod through the damper all the way to the end, push the tip through the second hole in the stove pipe, and twist the rod to lock it into place so that both the damper and the rod handle are in a horizontal position.
- Turn the damper handle a few times to make sure that it moves freely inside the pipe.
- Reconnect the pipe section that contains the damper to the other sections, and screw it into place.
Stove pipe is manufactured in two standard sizes -- 6 inch and 8 inch. Be sure to buy the damper in a size to fit your pipe. Use a fluorescent marker to mark where the holes will be drilled on dark stove pipe or a black marker on lighter metals. Be sure to drill holes away from the stove pipe seams, as drilling through this area could weaken the pipe. Self-regulating dampers are also available as shorter sections that fit into the existing stove pipe. They open and close automatically depending on the amount of air available in the room to move smoke out of the stove.
Separating the sections of a stove pipe may loosen them up and create unsafe gaps between them. Apply a thin coating of stove cement between the male and female ends to reinforce the seal. In some cases, a stove pipe damper can create problems by keeping the pipe too cool, which encourages excessive buildup of creosote, the thick black residue produced by burning green or damp wood or by smoldering fires. Use the damper only if you need to, as in the case of a fire that is burning too hot. If you suspect a chimney fire, close this damper completely to cut off the flow of air inside the pipe.