Methods of Bending Wood
By: Rob Smith
After building a few simple projects in your shop, you may have
the desire get more creative and build something that requires
more advanced techniques in woodworking. One of these advanced
techniques is wood bending.
There are a few different methods used to bend wood. I will
try to give you enough information on most of these wood bending
techniques to allow you to get started on your way to more creative
furniture. These methods will include Steam Bending, Kerf-cut
Bending, Laminated Wood Bending, and for small pieces of wood,
Microwave Steaming. You will also need to know how to prepare
forms and molds before you can bend the wood.
Forms and Molds for Bending Wood
Before attempting to bend wood you will need to have a mold
or form set up. Steam bent wood needs to be placed in the form
and clamped in place as quickly as possible after being removed
from the steam box. Laminated wood also needs to be placed in
the form and clamped before the glue begins to set.
Most forms and molds are easily made from MDF. You will have
to glue multiple sheets of MDF together to get the thickness
that is about the same as the height of the piece of wood you
are forming. After you glue up the MDF and it is dry, you have
to square up the ends, for easier clamping later on. Then trace
your shape on the form, and cut it with the bandsaw, take care
to save both sides of the form. They need to match like a puzzle
piece. Then smooth out the cut with a pattern makers file and/or
sandpaper, to refine your form’s shape to perfection. Finally,
glue a strip of cork to each part of the form. This will help
to provide equal clamping pressure to the piece and a slight
cushion help prevent marks on your piece of wood.
 Another alternative for a form is a theory I have been thinking
about. I have not tested this and can not say for sure it will
work. If you would like to experiment with it, please email me
and let me know if it worked. I will provide the details below,
think about it and use your own judgment in whether to try it
or not.
My thought is that a peg board form would work for sweeping
curves. You would start by drawing out your shape on a piece
of 8/4 or 2” hardwood stock. Then you would drill and place
hardwood dowels at the apex of the curves. When the dowels are
in place, you are ready to place your work piece into the jig
and clamp it to the dowels as the blue marks indicate in the
diagram below.

Steam Bending Wood
Steam bending wood is probably the most widely used and accepted
method of wood bending. It has been used for ages
To construct a steam box you will need.
• A heat source to make to steam
• A container to hold the water to be heated
• A hose to connect the container to the steam box
• A box to hold the wood to be steamed. Can be either a PVC pipe
or a wood box.
• Various fittings, clamps, and screws to put the steam box together.
The heat source can be a camp stove, or just a hot plate. Open
flames in a wood shop can be dangerous, so I would prefer a hot
plate.
The container to hold the water can be anything you want. A
tea kettle works well, but some people use NEW and UNUSED metal
gas cans, pressure cookers, etc. You have to be able to attach
a hose to it somehow, with fittings and such.
The steam box itself can be made from PVC pipe, metal pipe,
or a simple wooden box you make from scraps in the shop. It don’t
really matter that much. Steam has to be able to escape, or else
the pressure will build and cause it to explode. But you want
it to hold the steam enough to heat the wood and force water
vapors into the wood. Roy Underhill from the Woodwright’s
Shop uses a wad of rags to plug the end of the box, and you can
see the water dripping out of the end. If you use a PVC end cap,
drill a hole or two in the end to allow the steam to release
to pressure as it builds.
Now just assemble everything and try it out. Be careful the
steam will heat everything up, so use gloves. The general rule
of time is about 1 hour for every inch of thickness being steamed.
Use this as a starting point, and adjust your time as needed.
 Laminated Wood Bending
Laminating wood to bend it is a fairly simple process. You will
still need a form or mold but you won’t need to build a
steam box or risk burns with steam. Thin pieces of wood bend
easier than thicker ones, but aren’t as strong. So by laminating
thin strips of wood together in a mold or form adds strength
and when the glue dries it will hold the shape also.
To bend wood with lamination you need to use thin pieces of
stock, longer than your final length needed, you will trim to
length after the bending is complete. To get the thin stock you
can either buy it, or make your own by resawing thicker stock
with your bandsaw. Pieces 1/8”or thinner will be easier
to bend, but depending on how thick you want the piece in the
end, you may need use a lot of pieces and glue.
After you have your form or mold ready and all your thin stock
ready, all you do is spread glue on the pieces and stack them
together in the form and clamp. When the glue is dry you can
dress the edges and trim to length.
Kerf-cut Bending
Kerf-cut bending is done by using your saw to cut slots across
the stock. This will allow the stock to be bent because the kerfs
can compress together. The kerfs are usually only used on the
inside of the bend. If you want to make a more complex curve,
perhaps an S- shaped curve, you would cut the kerfs on the inside
of each bend, then you would use a veneer you cover the entire
piece.
 Microwaving Wood to Bend it
Basically this is just steaming, and is used for small pieces
of stock. You wrap the stock with a wet paper towel and microwave
for a few seconds. The microwave heats the wood and water just
like a steam box. The time will vary depending on your microwave,
the species of wood, the wood’s moisture, the dimensions
of the wood, etc. You will have to experiment to find the proper
amount of time, start out with 15-20 seconds and work you way
up from there.
Finally
There are a few more methods of bending wood out there, but
they aren’t widely used and there isn’t much information
available on them. These methods described above should be all
you need to get started in the shop making more creative pieces
of furniture. You might have to experiment a little but that
is part of the fun of working in the shop, trying new things.
So have fun but be careful.
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