New to steam bending. I have built a new steam cabinet using PVC. Steam entering at the front of the tube using a 1″ hole and exit at the rear using a 3/8″ vent hole. Unit maintains 210 degrees. Trying to steam 1″ white oak (green wood). After steaming for 1 hr, then 1.5 hours the wood will not bend. Suggestions?
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Take a look here and see if it answers your questions.
http://www.leevalley.com/wood/page.aspx?c=2&p=45869&cat=1,45866,45867
1x what oak? What are you using to generate the steam? It can take a strong billowy amount of steam for larger pieces. Temperature doesn't mean you have sufficient steam. A 1" inlet in a large box generated by a wall paper steamer or tea kettle won't cut it. The wood only stays plasticized for a few seconds, so you have to get it in the form quickly out of the box. I like to have some pressure in my box, not so much that the ends blow off but enough so the vent hole is blowing a steady plume and you want to stand back, wear gloves and a face shield when the door is opened. The one hour per inch rule is just a guideline. Time will depend on the stock, the amount of steam and how much you need to bend it.
Beat it to fit / Paint it to match
Thanks, your comments make sence. I am using a tea kettle to produce steam but will look for something with more courage tomorrow and see if that will work better. In addition, I built a jig today that allows me to use a comealong to draw the mold together -- that made a difference.
get a gas 5 gal gas can and what we call up heya in Lobsta country, a lobsta boiler .......you'll be making stean all rightWicked Decent Woodworks
(oldest woodworking shop in NH)
Rochester NH
" If the women dont find you handsome, they should at least find you handy........yessa!"
Depending on how large a piece you are trying to steam, you will know when you have it right. The piece will be very pliable, almost rubbery. Cherryjohn has it right, I hack stuff together, the simpler the better in some cases. I don't know where to send you in the archives for a picture of my trusty steam box, so I'll re-post it here. I went the 5 gal. can route with a radiator hose into a length of PVC pipe. I found an old side burner from a BBQ. I use tea kettles to heat up water to add to the boiler. That way I don't get any lull in the steam production. It helps to have a boiler that you can add water to without disconnecting anything. The heat has quite an effect on the PVC schedule 40. I have a length of aluminum soffit vent in the pipe to keep the lumber out of the condensed water. Crude, fast and cheap but it works.
Beat it to fit / Paint it to match
Edited 12/1/2005 12:14 am ET by hammer1
Thanks to all for all the great feedback. I have begun my quest for a higher capacity steam source. That seems to be the limiting factor.
Hammer1 -- thanks for the photo
I know a few woodworkers who use propane turkey fryers to boil water and they have had good results.
I'm one of those. A 5gal galvanize gas can and a turkey fryer will create steam forever.When our troop build its dog sled, we built a box and insulated it with foil laminated building foam. We made two inlets with the idea that we wanted to even up the distribution of the steam. We were bending ash witch is porous. White oak is not and will require longer times. What's your hurry. if 1.5 hours doesn't cut it, try 3. You only need to make sure there's water in the pot :-)
wow.i am impressed! and all along I thought you were just a hack with good marketing...like MosherWicked Decent Woodworks
(oldest woodworking shop in NH)
Rochester NH
" If the women dont find you handsome, they should at least find you handy........yessa!"
I tried steam bending several times but have since moved to bent laminations, it's more sure fired, for me. One thing that both methods depend on is straight grained material. When you say it won't bend, I assume it breaks when you try to bend it. Some one that would be great to go to with this is Brian Boggs, who has just joined this forum. His chair making uses steam bending extensively. Bill Lindau
I have done steam bending with a homemade contraption and a tea kettle - - forming trim for a gothic church window - I used 1/8" thick white oak and placed it on a form, then glued the next piece and continued with 3 or 4 pieces. Once the glue dried, it was a perfect fit for the window.
An old pressure cooker with a hose leading to your PVC might help. You need a lot of steam under a little pressure to accomplish the plasticity for your project. This will require a good heat source (high btu burner). Good luck with it. Aloha, mike
Dami,
I use a steamer similar to one in the picture except that I have the radiator hose enter at one end. I then have the PVC pipe at a slight angle so that the exhaust end is slightly higher than the inlet side. This way the condensation runs back down the hose and back into the gas can (new, never had gasoline in it). I find that I don't need to refill the can as often this way.
I have a few dowels running across the PVC that keep the project wood off the bottom of the pipe where the condensed water will run. One more thing I did was to support the PVC tube with a full length board from below, this way although the PVC heats up it doesn't sag or bow.
Good Luck, Hugh
Hugh,
I'm reading this thread with interest because a friend of mine had a pair of bamboo chopsticks which are square (not cylindrical) with a quarter-twist in each one. She asked me if I could make more, and possibly use different wood. I suppose they could be made with some clever carving, but the bamboo sticks have clearly been twisted - I assume with steam. Do you know whether Bamboo is particularly "twistable" , or could this be done easily with any wood of such small stock? Would fuming be neccessary? I've had very limited (unsuccessfull) experience with steaming, but would like to try again.
BTW, sorry to hijack this thread everyone, I'm just looking for some advice from those whov'e done this. Anyone?
Saulgood,
I have to admit that I've never tried steaming bamboo. This is just a thought but if you have some chopstick sized pieced of bamboo why not try boiling them sort of like spagetti. It shouldn't take long, put spring clamp on each end and give 'em a twist. Just do a few to try it and if it doesn't work your not going to be out alot on the "stock".
Who knows, maybe somebody else has already tried it and will chime in.
Good luck and "Bon Appetite".
Let me know how it goes.
I have twisted oak and catalpa with a little steam . The one thing I learned was that you need a little more twist than a 1/4 if you want a 1/4 twist to stay
The most I could get was a 180twist . I tried to get a 3/4 twist several times only to snap the wood. I was useing 1inch wood . smaller chopstick stuff will twist and bend much easier.
I bent 3/16 rounds by just boiling in water for a few minutes.
I have been learning a lot from yall's experience. I have made a lot of bent laminations and am getting pretty adept at it. I always assumed that steam bending would be harder and more unpredictable. Of course "when you assume......." so now I am wondering if I should be looking at steam bending.
Can someone list out the pros and cons of steam bending vs. glueing up laminations?
Mike
It is more unpredictable than laminated bending mudman.
Some of the pro's are:- one piece of wood that can be shaped or profiled after bending without long glue lines being exposed during the profiling/shaping. Reduced amount of wood used-- only one stick is needed. Green or air dried wood is preferable over kiln dried stuff, and because of that it's generally cheaper to buy. No gluing up of separate laminations procedure.
Con's include:- unpredictable springback, or the rarer spring in. I generally reckon steam bending is best used where the ends will be locked in some way, e.g., a bent back into a Windsor chair seat or similar. (Incidentally, there are formulae out there that are said to predict springback in both steam bent and laminate bending work-- in my experience they're all cobblers because none of them allow for the aforementioned spring in which does actually occur every now and then.) More kit required-- you need not only the former or bending jig but also a steam generator, a steam box and a restricting strap for many bends to move the neutral axis to the outside of the bend thus reducing the chance of compression and tension failure. It's harder to achieve particular effects, e.g., a striped look that's often only achievable by laminating different wood species into a shape. It's not suitable for plywood bends which generally need to be done as laminates.
In the end neither method is actually better than the other. It's just a case, as always, of weighing up what effect you are after and applying the right technique to a particular job bearing in mind things like aesthetic, construction and structural requirements.
There's also the technique where a combination of steam bending and laminate bending is employed, which offers some interesting aesthetic and structural possibilities. Slainte.Richard Jones Furniture
Thank you very much for the reply. It looks like I will continue glueing up. I don't know where to get green lumber in the selection I am acustomed to, and the unpredictable nature of steam bending sounds like it could cause me problems. However, I hate buying 6/4 lumber to get a 3/4" rail. This has been a very informative discussion. It is a shame that FWW dosen't seem to challenge us with discusion about more advanced techniques anymore. The last few issues were not really any different than Popular Wood Working or the other entry level hobiest magazines. I remember reciently "basic machine techniques", or something to the effect, and "Yet another jig for making tennons". I find myself flipping through the issue to see if there is any good information, and more often I leave it on the rack.
Maybe they should look at this Forum and pick topics that are discussed around here. But I supose that the most popular discusions here are the "better fitting tennons" type discussions. Or every ones favorites : router vs. shapers, jointer or planer first, cabinet saw worth the money?
Perhaps it is me that has changed. As I learn more I expect more from the editiors. Sorry for rambling, I don't think I have ever critisized the magizine before, but discusions like this remind me about a time when I could count on FWW to challenge me.
Mike
All woodworking magazines face criticism from their readership mudman. It would have been very hard for Fine Woodworking to retain all the readership it picked up in the late 1970's when it started.
Early subsrcibers, well, many of them I suppose got old and died, and if it's assumed (not necessarily correctly of course) that those early subscribers are still alive and their skills and knowledge grew year on year then the content of the magazine would have, by and large, needed to grow with them to retain their interest and their subsrciption. (I know I'll probably get some feedback on that comment, ha, ha.) There would perhaps be finely wrought articles on highly scientific elements of wood technology for instance, or an in-depth study of tool steel and carbide tool tip chemistry in amongst some advanced woodworking techniques.
Weekend woodworkers new to the game and muddling along with a great deal of hope and not much face to face instruction wouldn't be interested in such hi-falutin esoteria but the advanced furniture maker might be-- well it's the sort of stuff that catches my eye as being of interest anyway.
It's inevitable that less than advanced topics reappear in woodworking magazines. New woodworkers get started all the time and need to know basic stuff so most woodworking magazines write for them. I think it's true to say that most woodworking magazines retain their subscribers for about three years before they drop off. There aren't that many subscribers to FW I'd guess that have been faithful to the publication for all of its near thirty years.
I never have been much of a reader of Fine Woodworking. It's a good magazine-- I know that because I do check it out to see what is being discussed, which takes maybe ten minutes. Taunton I guess knows its target readership, and I think I subscribed for a year or two, perhaps three, but it's been rare to read something in FW in the last couple of decades that's really got my attention.
There's nothing wrong with that-- I'm not Taunton's target reader. Similarly, they know people such as myself are unlikely to sign up to their new subscription forum. I'm also not willing (at this stage anyway) to fork out ~£38 a year to check it out either, ha, ha. Slainte.
Richard Jones Furniture
Edited 12/6/2005 8:25 pm by SgianDubh
I would also point out that there must be 3-4 articles on steam bending in the archives and you can get those articles for a couple bucks. Do a search with a credit card and you'll be surprised.Depending on the size of the board, you can actually cook the wood in water, e.g., boil it prior to steaming or in lieu of steaming.The other rigs I have seen include the gas tank method over an outdoor propane stove previously discussed, and converting a propane tank to a steamer using an electric water heater element. The latter was a really cool rig, and it fit nicely into a large plastic milk box/carton, with the cord and tubing. I would also insulate the steam box with foam so that it retains the heat better. My two cents.Regards, Scooter"I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934
You are right of course. However when I first started learning It was the relatively advanced articles (I remember FWW doing articles on carbide compisition and tool steel grades) that challenged me and brought me to where I am now, I still have a long way to go. But there are a half dozen popular wwing magazines that are geared to wards the begining ww'er, FWW has always seemed to shoot for the more advanced craftsman.
Here is a great example. I used to read Fine Home Building religiously, that mag has DEFINATELY refocused its coverage. However I subscribe the the Journal of Light Construction and they continue to focus on the profesional carpinter/contractor. Of course this publication cannot be found in the magazine racks at the grociery store. It is only availible to trades people through subscription.
Likely you are right that I (and many other complainers) have reached that three year point where we are no longer gaining the benifit he once did.
Hasta Luego,
Mike
Steam bending isn't quite as unpredictable as some suggest. There are many applications that don't require backing straps or green lumber to make it work. One thing with steam, is that it works better if your pieces are somewhat close to square in section. A 1x1 is fairly easy to bend but a 1x6 will likely cup in the steaming process. Bending a small molding around an arch where it can be glued or otherwise locked in place is an appropriate use. Trying to bend a stairway handrail may be better suited to a thin lamination process. Making a serpentine style chest may be better approached by gluing up blocks in a brick like fashion. It all comes down to what you are trying to achieve.Beat it to fit / Paint it to match
I used to use an automotive transmission fluid cooler core (looks like a small radiator) attached to a garden hose and then perched on the smoke stack of our kerosene 'hardhat' heater. A trickle of water from the hose would change to steam instantly and I would pipe it in to whatever steam box I needed. Worked perfectly. Nice "dry" steam every time. By the way it is the heat that breaks the hydrogen bonds in the wood and allows bending. Steam is useful because it carries with it the heat of vaporization which allows it to transfer heat more effectively. Small pieces of wood can be placed on a wood stove and they will bend easily once hot - Underhill on thw woodwright's shop has used this method many times.
I know a brilliant New Hampshirite (sp?) who, rather than use a rigid steam box, encases the wood to be bent in a long length of plastic bag material, and connect the steam source to that. He bends the wood while still encased in the bag and the steam, which takes the time pressure off as far as once removed from the steam the time of plasticity is short.
I've bent hundreds of white oak bows, arms, and combs for windsor chairs. You've got some good advice from the posts. Here is what I use. I built a plywood box - just screwed together a long box about 4" X 4" inside dimensions. It's really cheap but you need to screw it together well. I use burlap rags to plug up the ends - you want the steam to escape but you don't want a draft of outside air circulating through. I cut a large slot in the middle underside of the box and made a circle piece of plywood which screws to the middle underside of the box with the same slot cut in it. The circle piece of plywood fits inside the top of a 5 gallon can with the top cut off. (The slot is narrower and shorter than the lid of the can.) The box holds it , the circle, near the top of the can - swing poles on the end of the box balance the whole thing. With this fixture I get tons of steam up into the box and don't resrtict it with the conventional radiator hose. The can sits on a propane fish cooker, barbeque, lobster cooker, turket boiler - whatever they call it in your neck of the woods. (I use this outside the shop - near an entrance door.) Done this way, fresh white oak 1" in diameter will bend like slightly stiff rubber for about 1 minute after steaming for 45 minutes to 1 hour. IMO unlike red oak, where the steam pentrates the wood, in the case of white oak, it's just the heat from the steam that does the trick, but you can dry the wood out if you leave it in too long. It's a challenging but fun treck - people who have been doing this for years and years are still learning. Chairwright
steam bending in plastic bags
Steam bending in plastic tubing. Not sure if this has been shown in this thread and it seems like a game changer:
https://www.youtube.com/watch?v=--iPQIwSEJM this one as well; forward to 3:08 for the bending
https://www.youtube.com/watch?v=7JFePos8RQQ
I'm trying to bend a redwood 2x4 to make an arched top frame for a bamboo gate. I've dadoed the 2x4, made the jig and created a steamer using 2" OD spa hose and a round cookie pan with a 2" hole cut out of it. I put that on any large pot and use the propane setup for a turkey fryer. It generates a ton of steam. From what I understand the recipe calls for fifteen minutes of steaming per .25" thickness of wood. Gonna steam it for two hours and bend while still steaming. Will post if it works.
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