Instructables
A steam box is a handy way to heat wood so that it becomes more pliable than it is at room temperature. Once pliable, you can bend the wood into shapes that you couldn't bend it into cold. Size of the steam box depends on the length and diameter of the wood that you intend to bend. In general, it's good to make the steam box just a little larger than the wood that you're trying to heat. The smaller the steam box, the faster it heats up and the sooner you're bending wood.
I use a short steam box for bending ribs for kayaks. The ribs are 1/4 inch thick and 3/4 inches wide and usually less than two foot long. I use a long steam box for steaming coamings that go around the cockpit of the kayak. The wood for the coamings is about 7 feet long and 3/4 inches by 1-1/2 inches in cross section.
 
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Step 1: Materials list

You will need 5/8 inch or 3/4 inch plywood in the appropriate length. Thinner plywood would work but loses heat too quickly unless you add insulation to the outside of the steam box.
You will need a coat hanger or a few feet of heavy wire as supports inside the steam box to keep the wood off the bottom so heat can get to it from all sides.
You will need a cooking pot. A two quart size is good for starters. You can fill it two thirds full and generate steam for several hours.
You will need a heat source. If you plan on working outdoors, a camping stove works fine. If you work indoors, you can use a hotplate. The hotplate I use runs 750 watts. That is hot enough for the three foot steambox I use and just hot enough for the 8 foot steam box.
Since first writing this Instructable, I have gotten my hands on a wallpaper steamer.  It works much better than boiling water on a hotplate, mostly because it runs at a higher wattage and puts out more heat.  If you can get a used one, go for it. 
Bigolkj1 year ago
what kind of wood makes good crossbow limbs that I can maybe buy at the home depot? I have been making cross bows out of fresh cut wood, and wanted to step up the quality..message meback if you know any tips.
myoung49 Bigolkj4 months ago

If your serious about making a bow whether it be a cross bow or a long bow always do your research. The wood traditionally used for making a bow were hickory and lemon-wood, or bamboo and yew. if these types of wood are not available in your area then you have two options, find substitutes for the above timber or go to an importer that imports the material from whatever country where it is grown. I hope this helps

Your best bet would be to go with Osage Orange. Very popular in the best long bows, recurves, etc. Do an ebay search for Osage Orange bow staves
nativewater (author)  Bigolkj1 year ago
Good luck with Home Depot. Where I'm at, they have pine, poplar and red oak in clear lumber, none of which is typically used for bows. Try to get some hickory or ash if you can at a wood place that targets cabinet makers.
zacker1 year ago
Hey, anyone have any idea why I cant post or reply to anything except for places I already posted to before? Like this instructables? this has been going on for about 3 weeks now. I cant even post to the boards or forums here, only to instructables I posted to prior to a few weeks ago. What's changed?
zacker zacker1 year ago
oh sorry for posting my problem here but I cant post it anywhere else...lol sorry.
ardnon1 year ago
Very nice, very simple, I want to try it... thinking of making a wooden toboggan...
mauro12mdp4 years ago
Seems to be kind of simple =) ...
Should this work to bend something like a bamboo cane ? have you got any tip for bending bamboo canes ?
It's better to bend the cane when it's still green ?

Thanks a lot for the instructable anyway =)
nativewater (author)  mauro12mdp4 years ago
I haven't tried bending bamboo cane.  I know that people have bent split bamboo. Yes, in general green stuff bends better than dried. Go ahead and try it.  Investment is small
ok I'll try 
Thanks for your dedication. Then I'm going to tell you how I did the bamboo bending ( or make an instructable for it)

good luck =)
Hey did you try bending the bamboo? I'm looking into bending and setting cane at the moment and have a feeling they might have similar properties...?
Yes I tried but the canes might had been too green for bendings or I don't know. The problem was that the canes got degraded and lost its hardeness. I suppose that due to environment, humidity and funguses. I guess that if you wanna try this, you should keep an eye on the place you store them so as not to have the same problems.

Good Luck with your work =)
 I just found you while searching for information on wood bending, but specifically with use of PVC pipe.  This is listed in several articles but my plumbing sources tell me it shouldn't work, due to shape changes in the PVC as the temperature goes up.  I have already purchased a 10' section with a 12" diameter and walls measuring slightly greater than 1/2". Have I wasted my money? Do you have any experience with use of PVC piping for such purposes?  Thanks. 
nativewater (author)  woodworkingnut4 years ago
I've used 4 inch ID pvc pipe as a steam box.  Works fine with some reservations.  If you're concerned about shape changes, give the pipe some support so it doesn't sag in the middle. 
Secondly, a 12 inch diameter by ten foot long pipe will take quite a good source of steam to get up to temperature.  You will need something more than a one quart pot of water.  Also, the pvc pipe loses heat, so if you put some insulation around it, you won't need as potent a heat source to get it up to temperature.


Hey guys, I've never bent wood but am thinking on making some snow shoes. This is the first reading I've read about making a steam box and have thought of using PVC. Kinowing the basics and the characteristics of such, I didn't know if it would work well. My next thought was of using double or triple wall stove pipe. What do you think?
In my duct box, I started out with boiling water for steam/ heat, but found I was getting plenty of moisture [maybe too much], but not nearly enough heat. So I added some parts and set my shop heater up to provide the heat. Now I just squirt a little water on the wood and place it in the hot-box for only a couple of minutes. Brilliant! My material is quite thin so It's easy to warm it up quickly without it getting too wet for the glue to set up properly. And, the heater works so well, I won't bother insulating the box at all.
nativewater (author)  a rigger2 years ago
Yes, having a good heat source is important. I haven't tried bending wood with dry heat myself but heard of it being done.
I've got two different suggestions if that 12" pipe didn't work. The first is that I used parts from the duct-work guy. I used some 3"x 12" rectangle duct, and plan to someday build a box around it. A couple of A-dapter parts and I was good to go. That works great for wider pieces. Again, if the pipe isn't working... I've always dreamed of switching out my downspouts with 12" pipe. By my calculations 10 feet of pipe holds as much as a 50 gallon barrel. Food for thought.
Is it possible to steam wood with glued strips? I have a clipboard that I glued wrong and it's warped.
I would add a indicator bulb and a timer switch to stop that from being left to boil dry.
cconsultpa2 years ago
iam trying to build drum replacement shells out of maple any tips on bending the 1/4" maple around or inside a jig and would it be better to build 3 / 5"high rings and join them or to try and build 1 / 14" ring. Im a complete newbee to wood work especially bending. Any advice would be helpful.
nativewater (author)  cconsultpa2 years ago
Not sure about your dimensions and I also have not tried bending maple, but it should work. The best way to proceed is to do some experimentation before buying a lot of wood. There are a number of keys to success, but regardless of your process, having wood with good grain is essential. Grain of your wood should be straight, that is the grain of the wood should run parallel to the edges. Anywhere that the grain runs out of the wood is a place where it is likely to break in bending. The rest of the success story is just a matter of soaking the wood for a few days and finding the right length of time to steam the wood. Try bending the soaked wood before you put it into the steamer. That will give you a baseline of how flexible it is when cold. Then put it in the steamer for about 5 minutes and try bending it again. If it has been heated through, you should notice an increase in bendability. I typically bend around the outside of a form and have some clamps handy to hold the piece to the form. Also search the internet. There are plenty of videos out there of steam bending. Between all of them, you should get lots of helpful hints.
ilovetea6 years ago
I was thinking of making a chair using this technique, one similar to this but with a smaller wood sheet:
http://www.designboom.com/history/choi/22.jpg
Those chairs, and many like them are made just like regular plywood only with a bent press instead of a flat one. Some heat is useful, but as thin as those veneers are, you should have no problem making that kind of radius curve. If you can source that material in less than railcar-size loads, let me know.
tinker2342 years ago
very nice job could i make one with plastic bags for insulatun i heard there very good
Dyyor2 years ago
Hi, will this work to bend a 1 in diameter dowel? It is about 4 feet in length.
nativewater (author)  Dyyor2 years ago
success depends on a number of factors. Grain has to be straight. Wood species have different degrees of bendability. Success also depends on how tight a radius you are trying to bend. Success improves if you incorporate some kind of back band into your bending setup to prevent grain tearout. Finally, the thicker the wood, the longer the heating time. Experimentation is in order. And some expectation of early failures helps minimize disappointment.
pquin34 years ago
Could a steam box be used to straighten a warped guitar neck? I would think that a box could be constructed that would contain only the neck portion that needs to be straightened, and which allows the guitar body and the head where the tuning pegs are to extend out opposite ends of the box. Would there be an easier way? Also, it might be tricky to get it to cool to retain a true and straight shape. A straight jig would be important I'm sure. Anything else? Or is the whole idea just a waste of time, trying to fix something that is already toast?

Thanks, pquin3
nativewater (author)  pquin34 years ago
The question I would ask would be, what caused the neck to warp in the first place? If it started out straight, then warped, then is steamed back into position, what will stop it from warping again?

Your scheme for straightening the neck via steam and then locking it into a straight shape might work. And if it does, you would be the world expert and could write an instructable about it.

On the other hand, dried wood does not steam bend as well as wet wood or green wood, I assume guitar necks are made from well seasoned wood. Might be easier just to put a new neck on the guitar.
Use the truss rod to straighten it
and yah, if your neck is warped then its a pretty crapy neck cause it should warp but maybe 1/8" if it does warped and not even that much the truss rod in it shoul keep it straight thats what its there for, so that the tension of the strings doesnt bend and warped the neck or eventually cause the neck to snap.....so either theres no truss rod in it or you have a very crapy neck or your neck has a crappy truss rod
no actually it wouldnt be easier to put a new neck on the guitar because each neck is different they make them from different types of wood but thats besides the point....necks come in different sizes, then neck you have could be 3" x 4" where it screws to the body and be a 22 fret neck and you could go buy one and it be 3.5" x 4" where it screws on and also be a 22 fret neck plus taking the neck off a guitar isnt good for the body itself...i would take a piece of pbc pipe that has a big enough diameter for your guitar neck to fit in and is about 5 inches longer than the neck, seal one end of it up pretty good (ducktape a trash bag to the end) then place your guitar neck in it hang something that will provide water vapor in to the pipe (i.e. an electric kettle/ also make sure to tilte the pipe with the sealed end sticking up that way the water vapor goes into it), then ducktape a trash bag to the other end but not all the way around only bout halfway around the pipe, and then place a thick blanket over the whole thing to provide insulation and then when the neck is nice and moist go take it and brace it straight (you could take two peices of 2x4 that are the length of the neck and place one on the top and one on the bottom then take two clamps and clamp then together tighly to hold them tight place one clamp on the right side of the neck at the top and the other clamp on the left side at the bottom to even out the pressure pretty well) and let the neck sit and when the water vapor evaporates from the neck you should be good!!!
abadfart6 years ago
can you use this to build a guitar ??
yes you can place the wood in the steam box and let it get nice and moist and then use an outlinne shape that you want to make the guitar and shape the wood on the inside of that outline shape and then let the moisture evaporate from the wood and youll be good, the wood will try to bend back in to its original shape thats why you need an outline shape so when the wood trys to bend back the outline shape will stop it from doing that. you also want your outline shape to be a little wider than what you want the guitar shape to be, allow for the thickness of the wood your bending. if your trying to make an electric guitar then no unless your making a hallow body like im going to.. if your making an electric guitar, those are built with many layers of wood that are then glued and stack on top of each other the use a jigsaw to cut out the shapes of the peices and then they are sanded down really well to get out all the bumps from where the jigsaw went out of line some companys also use laser cutters to cut out the peices of wood.
ya im wanting to do a hollow body like a real old gear tech
yah then you'll just want to decide how thick you want the guitar and decide how long of a length of wood your gonna need to make the side of the guitar then steam it and bend it to the shape, i would use a guitar case as a model for the thickness and shaping it because then you wont have to build a frame to shape it in and then its built to your case and you wont have to buy a new one. then youll just have to cut the front and back of the guiatr, id plase a board over the case witht ape on the board an then take a hammer and lightly tap th e bored on the edge of the case and you should get where you need to cut it, then cut those pecies out. then get some like 1x2's and cut those to make a frame on the inside and then just put it all together and out your neck in and you should be good
nativewater (author)  abadfart6 years ago
I assume you're talking about bending the sides of the guitar. If that's done with heat, then the steambox would work. You would probably also want some forms to force the wood into the proper shape.
otisbaldwin5 years ago
thanks a lot! :) I like your kyak it looks like its going to be nice do you have any suggestions on how to make a ball out of wood?
from reading your post I am picturing a chair where the person sits inside of the sphere?and since it has been 2 years I was wondering what you came up with
nativewater (author)  otisbaldwin5 years ago
There's a wooden sphere on the desk of the lumber yard where I get my lumber for paddles. I imagine it was made on a lathe. If you don't have a lathe, you can carve and file using some semi-circular template to check your progress.
thedude00784 years ago
Thank you very much...much appreciated! ..maybe ill try the wall paper steamer then if i find one for sale..Cheers
thedude00784 years ago
Just a question which ay be obvios...se the hole in the steam box for steam to get in it is at the bottom right? Thanks
nativewater (author)  thedude00784 years ago
yes, there's a hole over the cooking pot.
I have since found that a wallpaper steamer has higher wattage than a small electric heating pad and generates a lot more steam.
If you use one of those, you just drill a hole in the steambox the size of the hose on the steamer and run the steam right in.
otisbaldwin5 years ago
what about a hollow wooden sphere? or if i wanted a half of a sphere for a chair im really bad at explaining stuff but maybe you understand what im asking
any wooden spheres or half spheres youve seen have most likely been made on a lathe. steambending works on one plane (from | to \) not two planes(3D) it could work, but would be exremely ETREMELY difficult.
mandapander4 years ago
I have an end table that has one leg that has a twist in it.If i steam it can i get the twist out of it?

how long do you have to bend the steamed wood
nativewater (author)  CharlieHarley5 years ago
not sure about this question, is the question how long do I have to keep the wood in the bent position until the bend will stay? Assuming that this is the question, here is the answer: When you bend heated wood, the bending is a combination of elastic and plastic bending. Elastic bending when released lets the wood spring back to its original shape. Plastic bending permanently deforms the wood. As a practical matter, bent wood has to be locked into its bent shape permanently to keep the bent shape. In general this is not a problem because the bent piece is generally part of a larger structure. If the wood you bend is a stand-alone piece, then you have to experiment to see how much spring back you get and how much of the bend stays. When you steam bend, you probably have to overbend the piece so that after spring back you still have enough permanent bend in the piece. In general, when I do extreme bends, like bending wood into a circle, I leave the wood clamped to the form overnight. Once wood cools, it is less likely to spring back. Also, once it dries, it is less likely to spring back. When bending ribs for a boat, I clamp them in place right away so that the boat locks them into the correct shape.
altomic6 years ago
I used to use 2 aluminium deck chairs, a mattress plastic bag, and a broken kettle. lo-fi baby though there is a certain cool-ness (I can't spell je ne ces que) with this design that leaves it home made looking but bordering on professional in quality/outcome.
altomic altomic5 years ago
re-visit. I used this method to "fix" the tail of my skateboard back in the mid 80's. it seemed to loosen the glue as well as softening the wood and then once steamed leave it clamped for a week or so.
j0yb0y altomic5 years ago
Instructable-it! ;-) "Je ne sais quoi" - I know not what
TinKicker6 years ago
This is a great instructable, very applicable to the pull-behind camper I am planning to build. Do you have any ideas on a good (that is, efficient) way of bending large panels (such as plywood)?
There's a specific type of plywood, called 'bending plywood', which has the grain running in the same direction for all plies. I've never used it, but from what I hear, this is the way to go, if you need to bend sheets of plywood. Or, you can cut a series of closely-spaced kerfs (not quite all the way through the sheet) in the back of a sheet of regular plywood, and bend along the kerfs.
All of what Mark says is true but the whole idea of plywood is to give structural rigidity and laminations in the same direction will lose this strength. If what you plan to build is aesthetic only, then this is not a problem but by the sound of it, I would say that you wanted a finished construction that was very strong for its weight. The only way to bend plywood without loosing this attribute or risking de-lamination, is to use several thinner sheets, glued to each other one after the other, to the shape you require and make sure to change orientation of the grain in the laminations so you get an equal number of laminations for each grain direction, this will result in more strength for a thinner total lay-up, even so far as to use them diagonally if you can afford the cost of the probable wastage. If you want to bend in two axis at once, don't even attempt it, build a frame and use strip planking instead.
kd1uc TinKicker6 years ago
The real problem with steaming plywood is that it is built to be stable with the grain changing direction with every layer. Solid wood fibers stretch and compress to make the new shape and the grain is only one basic direction. The best way I know of to work with plywood is to use several layers of thin plywood. Quarter inch is very flexible and one can be glued on to of the other and then trimmed to shape. You have better control of shape and thickness and when it is glued it will hold the new shape better than solid wood. Plus I believe it would be stronger than a manufactured sheet of the same size. Believe it or not the 1/4 inch is better quality than 3/4 inch. The material cost might go up but the cost of making a one time steam box and the hours put into it is far more. Not to mention that you only have so much time after the wood is pulled from the steamer that you can work it. I'd love to see some pics of the trailer when your done.
nativewater (author)  kd1uc6 years ago
I am also reminded of the trucks we had in the army - The bed was covered over with wooden bows and those were covered over with canvas. Perfectly good for going down the road at 60mph.
See also this websites which has lots of links to traditional gypsy wagons:
http://www.enslin.com/rae/gypsy/camps.htm
A guy named George Buehler has also published a book called "Buehler's Backyard Boatbuilding." He uses the multiple layers of 1/4 inch plywood technique to create curved surfaces on boats and offers advice on how to make them strong and how to glue them together and make them waterproof.
nativewater (author)  TinKicker6 years ago
You could build a large flat steam box. You would want a high wattage steam source sufficient to heat up your steam box and plywood. I have bent 24 inch pieces of 1door skin into cones. If the plywood has voids, it tends to kink where the voids are if the voids run the whole width of the panel.
Although it would be more expensive, you might want to look at flexible plywood. It's usually thin like 5 mm, but you could laminate it up into thicker panels which would then lock in the shape and stiffen it. No steaming involved. There are probably multiple sources, just search for flexible plywood. Here is one source: http://www.marineply.com/stagflex.htm
ItsTheHobbs5 years ago
This is neat .My great-great (I think) grandfather was a wood bender from Norway, and this looks like a really fun thing to do.
nativewater (author) 5 years ago
Another thing about steam boxes is that you need sufficient amount of hot steam coming into the box to raise the inside of the box to 212F or 100C or close to that. One way to assure that is to have lots of steam. Another way to assure that is to have a well-insulated steam box. I built one eight foot long steam box that wouldn't get quite hot enough with an electric hot-plate as a heat source.
peerstrik5 years ago
Put the wires in before you screw in the last long side of the box.
nativewater (author)  peerstrik5 years ago
Good advice. If you didn't follow this good advice, the way to get the wire in is to be in a fairly dark room and shine a light in the box and look through the exit hole. You will then be able to see the tip of the wire coming and be able to steer it toward the exit hole.
okieinAZ5 years ago
If you are worried about leaving the steaming pot on too long, just make a timer outlet. Get a junction box, an extension cord, an outlet and a timer:
http://www.rewci.com/timinout.html
Turn it on by setting the timer for the amount of time you think you need, then if you run out of time while working just add more time.
I see this in thrift stores where people can test old toasters, etc. and not be bothered to turn them off themselves.
I prefer the wind-up kind.

Okie
corkey1236 years ago
How do you think steamed wood would react to epoxy resin or other glues (gorilla glue), It doesn't say anything on the packages, but do you think it would ruin the glue or something?
nativewater (author)  corkey1236 years ago
If you mean glueing after steam bending, the wood will still be moist after bending. Gorilla glue would work since it wants to have some moisture to make it foam up and fill gaps. I don't know about expoxy. Depends on the type I imagine. Worst case, you would have to let the bent wood dry for a day or so before applying epoxy.
So, if I were to steam my wood and then put it in my press and let it dry for a bit (day), would it hold its shape completely, or does the wood want to spring back to its original form (flat) if taken out of the form
nativewater (author)  corkey1236 years ago
The wood will have some tendency to spring back but it will not return to its original shape. Usually bent wood becomes part of some larger structure which helps it to hold its new shape. If your bent piece of wood is going to be free standing like say the tip of a ski, then you might have to over bend it some to compensate for the tendency to spring back.
would gluing two pieces together after bending help the wood keep its shape better. I'm also wondering if redwood would be suitable for bike fenders.
eiwtes6 years ago
you can also use a normal kettle with some type of funnel to concentrate the steam into the box, we use it in our shop, works great? i mean, it makes wood bendy! (sorry if someone already posted this)
Wyle_E6 years ago
Why not just make the top removable? It's not as if it has to hold pressure.
nativewater (author)  Wyle_E6 years ago
Yes, you definitely don't want any pressure buildup. That would be dangerous. A removable top would be ok if you only planned on bending one piece. If you bend a number of pieces in succession, removing the top would release too much heat out of the box and would require more time to build up heat for the next piece.
duckworksmagazine.com has all you want to know about boat building.
nativewater (author)  carolinatinpan6 years ago
Good resource for wood planked boats. And may of those designs can probably be adapted to skin on frame construction, once you get the hang of it. Best general resource for skin on frame boats is probably qajaqusa.org which also has a very active forum where you can ask questions and get answers from other builders.
SWV17876 years ago
This is a wonderful idea, a great way to do it. I believe that was a kayak in the start, did you make the entire thing with steamed wood or was some of it cut ply? and what do you intend to use as a skin?
nativewater (author)  SWV17876 years ago
No plywood in the kayak. Only the ribs and the cockpit coaming are steam bent. All the longitudinals are bent cold. The deck beams are cut to their curved shape, although some people laminate a bunch of 1/8 inch strips of wood together. At that thickness you can cold bend wood to some pretty extreme shapes. I have used cotton canvas, nylon, polyester and polypropylene fabric for skins.
what type of skin do you find is the best? eg. most durable easyist to work with ect. and do you have an instructable or any recomendation for a good resourse to make a small boat either kayak or dingie?
nativewater (author)  SWV17876 years ago
8 oz nylon is good to work with. Has some stretch and it can be shrunk one time with water for a good tight fit. The only downside is that it expands and contracts with changes in temp. I will have an instructible on how to make a kayak shortly.
I look forward to reading it. You definately seem to know what you are doing. I must admitt I am very impressed with what I have seen of your work.
Cool, I'll definitely make myself one after christmas, I've been looking for a way to bend wood somewhat cheaply. Hopefully I'll get a new dremel *Crosses fingers*. Great instructable.
This is great, its really going to help with the recurved bow i am making, i hadn't yet made the steaming process so maybe i will make this to bend the wood in to its correct shape, originally i had thought of submerging the whole bow in to hot water, but maybe this will do it better than that, something to try. PS i think you should try and post the kayak stuff.
nativewater (author)  Mr Tenacious6 years ago
some people favor boiling over steaming. You can keep a whole bunch of bending stock in boiling water and pull out one piece at a time as needed. There is some danger in steaming of drying out the wood if you keep it in the steamer too long. Hence you can just keep a few pieces in the steamer at a time. The downside of boiling is that you generally have to bring a larger amount of water up to temperature to keep your entire piece submerged. When you're steaming, you only have to bring about a quart of water to a boil. Boiling typicaly requires a larger heat source. re p.s. - I am planning on posting some kayak construction stuff
nativewater (author) 6 years ago
Good idea. Only downside would be how much heat you would lose every time you took the top off. Probably not too bad on a 3 foot steambox but on an 8 foot steambox it would be significant. If you're only going to steam one piece of wood, then a removable top would probably work. But if you're going to steam 20 pieces of wood, one right after the other, then you might lose too much heat each time you took the top off and would have to wait a while for the box to come up to temp. Whether it would work would also depend on the wattage of the heat source.
Maxx16 years ago
Simple...Great !!!! A plus from me !!
Wolf Seril6 years ago
Surprisingly, I have a lot of uses for this. Nice 'ible. You should post the kayak. BTW- for some reason every time there is an apostrophe in your 'ible it shows a bunch of random characters. I don't know if its just my computer, though.
nativewater (author)  Wolf Seril6 years ago
yeah. I typed in ms word and cut and pasted. I thought I caught all the funny characters, but will have to go back and clean up. & I'm working on an instructible for the kayak. coming soon Wolfgang
Nah, I see them too. I think he might have typed it up in something like notepad/wordpad and pasted it over to here.
i admit, this is very cool.
theRIAA6 years ago
cool