Green and air-dried hardwood are both suitable for steaming. The risk of breaking is too high for kiln-dried wood, softwood, and any lumber with less than 10% moisture content (15% for tight bends).Straight-grained lumber with minimal knots is recommended, but you can use cross-grained lumber with a grain slope less than 1:15.Hackberry and oak are among the best hardwoods for this approach; a 1 inch (2.5 cm) thick piece can bend to a curve radius as tight as 2 inches (5 cm). Maple, cherry, and poplar are prone to damage and only accept slight bends., Construct a tongue-and-groove box large enough to hold your lumber out of ¾" (19 mm) thick, exterior-grade fir plywood. Fit a hinged door on each end, and seal the joints with silicone and screws. Insert brass rods or wooden dowels through the sides for the lumber to rest on, so steam can circulate around it.Leave the box unpainted and unsealed so it can dry out between uses.


If you are only steaming parts the size of walking sticks or smaller, you can use a length of ABS pipe with a 2 to 4 inch (5–10 cm) diameter instead.
Another alternative is to melt 6 mil polyethylene into a plastic bag around your lumber. You can then bend the lumber while it is still in the steam bag for maximum flexibility., You can use an electric tea kettle as a steam source for steaming pieces 1" x 2" (19 x 38 mm) or smaller. For larger pieces, use a clean pressure cooker, metal gas can, or other large container over an electric hot plate; or rent a wallpaper steamer. Connect the steam source to your box as follows:Connect a 1½" (3.8 cm) diameter hose to the steam source with tightly fitted nuts. Cut a hole in the steam source if necessary to accommodate this.
Cut a hole in the base of the box and attach the other end of the hose.
Drill a few small drainage holes into the base of the box, especially toward one end. Set up the box so it slopes toward this end.
Optionally, drill a hole in the top of the box and plug it with a stopper. This allows you to insert a thermometer.
 Use a bandsaw to cut a stack of plywood into the shape of the inner curve. Screw the plywood onto a table to create a form to bend your wood around once steamed. To prevent the outer curve from splintering, you can either form a similar plywood back (just cut out the thickness of your lumber from the remaining plywood), or secure a metal bending strap to your table.Unless you are only bending a slight curve, you will also need to place clamps against the ends of the lumber.Metal straps may discolor your wood. If this is an issue, use an oversize piece of lumber and remove the affected area.
If you will bend the wood to a curve radius less than 4" (10 cm), you will need a stronger material to bend it around. Cut off the tip of the plywood corner and replace it with a piece of hardwood.
 Put the wood into the box, seal it, and heat plenty of water to create steam. As a general rule, wood needs steaming for one hour per inch (2.5 cm) of thickness at 212ºF (100ºC).Put in a few pieces of test lumber as well so you can experiment, since moisture content, wood species, and other factors all affect the wood's behavior. (For example, if your wood has a moisture content above 20%, you may only need to steam for half an hour per inch.)


If you have a thermometer, use a small hole at the top of the box to check the temperature. If it's too cool, wrap the box in an insulating material.
To avoid steam burns, wear work gloves and keep your face back when opening the steam box.
 The heat and moisture from the steam will soften the lignin, a substance responsible for wood's rigid shape. Immediately after steaming, place the wood against one end piece on your bending form. Starting at that end, bend the wood around your form at a moderate, steady pace. Compress the wood securely between the two pieces of plywood (or the plywood and backing strap). If the wood is not secure, the outer edge may stretch and weaken.If the wood cracks, it needs more steaming.
If the wood wrinkles along the inner edge, it may have steamed too long, or there may be too much compression.
 The length of time varies depending on the type of wood, thickness, and intended purpose. As a starting point, keep the wood in a well-ventilated location for 24 hours before removing it from the bending form.If it cooled sufficiently, the lumber should hold its new shape indefinitely.
Choose your lumber.
Build a steam box.
Set up steam collection and drainage.
Build a bending form.
Steam the wood.
Bend the wood onto the form.
Leave the wood to cool and dry.
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