wood-bending-msg - 2/6/11
Period and modern techniques for bending wood.
KEYWORDS: wood woodbending bending steambending steaming period rattan warp tools curving
This file is a collection of various messages having a common theme that I have collected from my reading of the various computer networks. Some messages date back to 1989, some may be as recent as yesterday.
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Mark S. Harris AKA: THLord Stefan li Rous
Stefan at florilegium.org
From: powers at colon.cis.ohio-state.edu (william thomas powers)
Subject: Re: steam bending (was Re: Making Portable SCA Furniture)
Date: 12 Aug 1997 19:00:21 -0400
Organization: The Ohio State University, Department of Computer and Information Science
>I had a couple of questions on steam bending...
>For smallish projects (such as in this book) how much room does a steam
>box (?) take up? What is a good source for information on how to
>construct such a thing?
The steam box will probably be 4-6" square and 6' long---it can be made
from wood, plywood, pvc pipe, thinwall metal pipe. since it is never
under pressure and doesn't exceed 212 degree F all it has to do is
hold the piece of wood and allow steam to circulate. When not in use
you can stand it in a corner or up in the rafters.
The Woodwrights series covers steaming. There was an extensive article in
Fine Woodworking magazine back in the '70s which is sure to be in
reprint in one of their compilations. The US Department of Agriculture
Wood Handbook has a section on steambending. Many traditional woodworking
books will cover it. Look under "bending" and "steam bending" in the index.
(I prefer the Fine Woodworking article myself)
>When did it start being used (in England and Northern Europe)?
I don't know. My sources are basically to look at a piece of furniture
and see if it was constructed using bent rather than hewn or sawn wood.
Not as hard as you may think in person by following the grain, in pictures
it is a guess based on construction and design details---you usually
design for the techniques you are familiar with. Note Oak is one of the
better steam bending woods with beech close behind---both well represented
in nothern Europe/england. One might also check when barrels were
constructed with heat bent staves.
>My understanding is that Henry the VIII's fleet was made using
>steam boxes, but I am told that the Viking ships were not, each
>plank being hewn to shape. Any thoughts or knowledge out there
>about either of these alledged facts?
Not my area of research.
>Thanks for any information you can give me.
>Real Men change diapers
Been there, done that, ruined several shirts....
wilelm the smith who works wood as an adjunct to smithing and as a means
of providing objects for a more period existance.
Subject: [Fwd: Re: *WH* War cross]
Date: Tue, 07 Apr 1998 14:59:35 -0400
From: rmhowe <magnusm at ncsu.edu>
Organization: Windmaster's Hill, Atlantia, and the GDH
To: stefan at texas.net
Dan Mackison & Hilda Jarvis wrote:
> Poster: Dan Mackison & Hilda Jarvis <g7f3h7gv at coastalnet.com>
> Reading the latest Oak has brought back a polearm design idea I once
> had. The idea also springs from once hearing that rattan can be bent
> with loving application of steam.
> Before I spend a lot on money I don't have building a rig to steam
> rattan I thought I would check to see if anyone else out there had such
> a rig or had otherwise attempted to warp rattan.
> Obviously, alternative methods to steam would also be gladly tried.
> What I am trying to do is take two pieces of rattan, 54" and 18". I
> split the shorter piece and steam/bend/warp it around the longer piece
> 18" from one end and secure it in place to form something like a cross.
Well, here in the library I have a book called Rattan Furniture
A Home Craftsman's Guide by Max and Charlotte Alth, 1979
It says you can get an 18" diameter bend out of 1 1/4 or a 26"
diameter bend out of 1 1/2".
It sounds like you are trying to make a short U bend in two
halves of the 18" piece at their center, while leaving them relatively
straight to be joined back together.
Commercially they would employ a steambox and perhaps hydraulic presses.
However, thick rattan can be bent by wetting it, clamping it in a vise
and heating it with a propane torch while repeatedly rewetting it with
a wet paint brush. You have to overbend. For furniture they build
bending fixtures to fit it into first out of wood blocks and panels.
In this case you might want to try binding the ends of the two halfs
with wire while putting the whole one between them. Then as you heat
them and they bend applying clamps, a rope twisted with a stick (spanish
windlass), clamps, etc. until you get it as near as you can.
The book suggests repeated heating and rewetting. Expect the outside
with silicon to fall off when it is bent. Charring can be sanded off.
A good steambox may be built out of a large plastic drain pipe 4-6"
with a hole in the middle and a cap on one end, a rag in the other.
One mounts this on an x trestle high enough to run a heater hose
down to a spout on a metal gasoline can filled with water sitting on
a gas cooker (like the kind you boil seafood on at campsites). Fine
Woodworking has plans for them. Norm baby also has had one on the New
Yankee Workshop. The heater hose fits in the hole in the middle of the
pipe. One steams about 1 hour per inch of thickness in most hardwoods.
Generally the fixtures overbend the wood a bit. It will spring back
a little when cooled and dried.
Magnus, repository of obscure materials and processes
Subject: Re: [Fwd: Re: *WH* War cross]
Date: Wed, 08 Apr 1998 14:46:55 -0400
From: rmhowe <magnusm at ncsu.edu>
Organization: Windmaster's Hill, Atlantia, and the GDH
To: stefan at texas.net
> Greetings Magnus,
> I have some wood projects that look like steam bending will be
> needed. Many medieval wheelbarrow handles appear to be smooth
> curves, not straight for instance. Your example steamer is only
> 4 to 6 in diameter though. This seems to imply that you steam
> the wood first and then bend it and hold it as it dries. What
> if you have to steam it again to bend it some more afterwards?
> You are out of luck?
> Stefan li Rous
(Put a heavy enough weight in the middle and steel will flex. ;) )
In bygone times wood was often selected for the shapes it was
in right on the tree, split in two halves and shaped accordingly.
One example would be cruck framed buildings, another would be
whiteoaking where the curves of the oak trees are used for ship
framing. Another would be the selection of various pieces of
trees for items like pieces in viking wagons or ship framing.
The World of the Vikings CD shows this use in the wagon
reproductions it depicts in process. Green wood could also be
shaped by tying as it grows in the tree or by bending into
forms before it dries. Remove the bark first. It is easy
when it is green - difficult later. Topiary would be a good
example of bending living wood. Many cultures like the
Europeans have a long tradition of copicing in which trimming
is continuously done to produce both hedges and usable wood
for withes for hurdling (fencemaking), basketry, the woven
wood sticks for wattle and daub between the framing in timber
framed buildings, etc. Mongols harvest the wood for their yurts
at regulated periods for the same reason.
Yesterday we discussed bending rattan with a propane torch -
alternately heating it and reapplying moisture with a wet
brush. I have also seen some ash bent that way - sheperd's
crooks for example. They splintered at the outside some and had
the outside of the bend flattened where they had been trimmed.
Of course these would have been bent wet / and or green.
Bending is basicly done in two ways with seasoned wood - either by
steaming or by laminating (lamininating can also be done in vacuum
bags on forms - particularly good for curved laminations out of
veneer for example. Very thin pieces can be heated in very hot
water and bent in a form - chair slats for example. Boiling too
long can reduce the properties of the lignin.
Mostly people use a wood like ash to steam bend. It has excellent
bending properties. Some woods don't bend at all well. Wood is
composed of cellulose fibers and lignin which is the glue that
holds it together. Wood cells are rather like long square
honeycombs. When steamed the lignin softens and the cells can move
a little. The outside must stretch, the inside compress, the center
remains pretty much the same. Some woods can't take the strain and
compression. Woods like ash and oak have very open grain and this
helps the steaming. Ash is also very tough - baseball bats and
tool handles for example.
In the case of hardwood bent for furniture both fixtures and jigs
are generally made for bending. A fixture is something that
does not move - like a frame, or a plywood board with curved
shapes/blocks screwed and glued to it. A jig usually has movable
parts and sometimes the two are used together. Below is a
common jig to bend fairly thick pieces. It would probably be
placed in a frame upon being bent.
Handle attached Wood piece to be bent End cap attached
to steel strap between handle and end with screws.
with screws cap with steel strap to Bears against end
\/ outside of bend of wood piece.
Steel strap is used to control the outside splintering of wood.
Very little space between the wood and the endcap.
Expect some failures. Split (riven) wood works best. Trying to
bend wood with poor grain not running lengthwise is most likely
going to fail.
Orientals sometime bend unseasoned fresh wood by placing it
in beds of hot ashes/coals and then bending it with jigs made of
poles with pairs of large dowels and / or forked trunks and then
tying it off once it is bent with twisted bark off the same pole.
Yurt roof wheels for example might be formed this way and then
cross lapped and bound where the semicircles join. I have an
example of a one piece yurt ring bent in a circle unjoined as yet
in a picture. Drilled for the roof poles later. I also have
a picture of a Mongol using a steam box to bend side poles for
Bending poles / forks for wood or metal often look like this:
| | | |
| | | |
|_| |_| wood or metal dowels.
Or make a 1 1/2" thick plywood form with holes you can insert large
dowels in for example. Kinda like a pegboard, and adjustable and
If you look in National Geographic June 1929 page 684 you will see
a picture of: "Little Trees are Wrought into Cart Wheels -
These wheelwrights at a village near Aksu heat poplar saplings in
ashes, bend them into semicircles by twisting bark ropes attached
to the ends like bowstrings, and lash them into pairs. Though the
hoops thus made tend to be more elliptical than round and are not
tired with metal, they serve excellently for traffic on roads of
earth. More expensive seasoned wood, studded with nails, is used
for vehicles intended for use on long journeys."
You might make a larger steam bending box by building a box
out of ordinary 1 x lumber.
|| dowels to place wood on go through sides //
|| o o o o o o o //
Hole for steam hose. Hinged door - not tight.
Or you can make the steamer out of a piece of heavy drain
pipe plastic with a cap on one end and a rag in the other,
with a hole to take a radiator hose with a steel gas can
attached to it. The gas can is filled with water and sits
on a propane burner such as you might use outside to cook
seafood. The pipe sits high on a sawbuck-like or trestle
To answer your question. Bending is generally done in one
operation, not multiples. Usually starting with seasoned
wood. In the case of fixtures it is also often held in
place with wedges between pairs of blocks or dowels until
it dries. Wedges are usually used in oppositely pointed
pairs to get a parallel surface. You bang the opposite fat
ends toward each other. Generally when the wood dries, the
wedges become loose. Allow about 1 hour per inch of wood
thickness for your steaming time.
Alternately - one can rip wood into strips and with glue
and clamps bend it in multiple layers around premade forms
of various shapes. Spiral staircases would be an example.
Complex twisting shapes, compound bends (bends in more than
one direction) are all possible. By laminating up sheets of
veneer you can make drum cases around round forms. Piano
cases are made in a similar fashion.
There are many excellent articles in woodworking magazines
and books - particulary those put out by Taunton Press who
publish Fine Woodworking. In fact they have a couple of
books on wood bending. One is by Tage Frid.
TAGE FRID TEACHES WOODWORKING: BOOK 2 SHAPING, VENEERING,
FINISHING. ISBN 0-918804-11-6
Another is FINE WOODWORKING ON BENDING WOOD
ISBN 0-918804-29-9 A compilation of many articles.
Fine Woodworking has been published for more than 20 years
now and they offer an index. Some of us have complete sets.
Unfortunately in all that time they have paid very little
attention to Medieval Furniture - most woodworking magazines
You might also look at books on Green Woodworking - which
generally cover chairs (bodgering) and the lathes used
(and built) in the woods.
Exellent examples would be books by Drew Langsner like
Country Woodcraft, Handmade, and Green Woodworking,
Make A Chair from a Tree by John D. Alexander, Jr.,
and Woodland Crafts in Britain by H. L. Edlin.
Langsner is an outstanding primitive woodworker. Drew
predates Roy Underhill and still teaches and writes.
For books on Windsor and Welsh chairs which have bent
forms you might try Windsor Chairmaking by Moser and
How to Make a Windsor Chair by Michael Dunbar. They
Date: Fri, 25 Feb 2000 19:52:26 -0800 (PST)
From: Christopher Douglas Buckley <cbuckley at gladstone.uoregon.edu>
To: sca-arts at raven.cc.ukans.edu
Subject: Re: steam bending wood
The most basic way to do it is to put the *thin* strips of wood to
be laminated into a bath of boiling water, over heat. (My father, a
luthier, used a coleman stove) Make sure the wood is NOT touching the
bottom of the bath, as this will scorch and discolor the wood. (One can
come up with a jerry-rigged system of holding it suspended in the water...
I think Dad used thin, smooth chain, hung from something.) After that's
been boiling for about ten minutes, take the wood out (carefully, it's
really hot... duh.) and test its flexibility... it should be able to bend
about twice as far as the final product is to bend. If it doesn't, set it
in the bath for longer.
If it does, you now put it into the mold. The mold is usually a
block of wood which has been cut in two, the cut being the shape of the
bend. (In the case of lutherie, it looks like the bust, waist, and hips
of the guitar... yes, those are actually what they call them.)
The contact surfaces of the blocks (where the newly-boiled wood is
going to fit) ought to have sheet metal nailed to them, so that the grain
of the blocks doesn't damage the grain of the product. There ought to be
holes drilled through the two sides of the mold, for the purpose of
clamping. (It should make sense where holes and clamps go, depending on
the shape you're trying to get.)
This has been long, but that's the basic gist of it. If you have
any further questions, I may be able to help, but maybe not.
Fr. Nathan O'Ceile
Prior, Our Lady of the Cross
Adiantum, An Tir