For the last nine years I’ve experimented a lot with “cold-bend hardwood,” which is also known as “compwood.” It’s basically wettish wood that can be bent radically when it’s at room temperature. And when it dries, it keeps its shape.
I first learned about the stuff from furnituremaker Jeff Miller, who showed it to me during a shop visit. Since then, I’ve purchased it from a variety of sources, including one local place that used to make its own (now they don’t) and Pure Timber LLC.
I don’t want to repeat the basic information you can get from Pure Timber. If you read the company’s descriptions and watch the videos you’ll get a good idea of what this stuff is capable of.
Instead, this blog entry is to talk about my experiences with the material and why I use the stuff.
First, let’s get the economics out of the way. Cold-bend Hardwood is expensive when compared to green wood that you’ve split from a log or lumber that you’ve bought from the yard. However, the math works for me.
Obtaining, moving and storing green lumber when you live in a dense urban area is possible. I’ve done it many times. But my supply is sporadic. The tree service I work with keeps its eyes peeled for me, but street trees are not always the best for splitting.
Then there’s labor and time of splitting it out and containing the mess in our small garden. Then there’s the agony when a bend goes sideways. The stick breaks or delaminates – or cracks when drying.
With Cold-bend Hardwood I’ve had only one bend fail in nine years. And there is almost no waste. It shows up in a box. I cut it to shape on the band saw and bend it in the form without a windlass or hydraulics. I then put it in an insulated box with a couple lightbulbs for a day (sometimes two days for big pieces). It comes out of the form ready to use with no springback.
For a chair, I need about $70 to $90 in Cold-bend Hardwood to make the armbow and crest. The time I save makes this expense work for me.
Before you use the stuff, please read all the directions. Don’t try to machine the stuff on a jointer or planer when it’s wet. It will self-destruct. Cut it to size on the band saw. I use a single-point fence on my band saw for ripping. You can crosscut it by hand or with any power saw with no problem.
If you have a drum sander, you can use that to clean up the band saw marks before putting the stuff in the form.
After it’s dry, I have had decent luck working with it most electric and hand tools. I plane and scrape the stuff. But have your handplane prepared as if you are working curly stuff – you need a tight mouth or a tight chipbreaker. If you run into trouble, rasps and sandpaper will get you out of trouble.
My No. 1 recommendation: Start with a light cut with any machine or hand tool. See what it gets you. Learn from there.
It finishes fine – just like regular wood.
All in all, I like the stuff. I also like steambending furniture components when I can get the right wood. I don’t see the two techniques as mutually exclusive. Instead, it’s another option that is open to all of us. And there are some projects where Cold-bend Hardwood is the best solution for highly unusual bends.
— Christopher Schwarz
Disclaimer: As always, I purchase all my materials and have never received anything of value from Pure Timber (or any other manufacturer). This post is not sponsored by anyone.
20 thoughts on “A Little Bit About ‘Cold-bend Hardwood’”
Mr. Schwartz, You are always amazing me with the amazing things you can do with wood. I’m glad you are spreading this great information.
It’s great to have alternatives.
You mention not to show this stuff to a power jointer or planer before you dry it. I am wondering, have you carved it with a drawknife when wet, and does it behave similarly to something that is (uh, for lack of a better term?) “traditionally green?” And how about ripping and planing by hand?
This is a corollary to the question about carving with a drawknife — is the grain orientation in this stuff as if it were split instead of sawn, so that you have very little short grain and can generally carve in any direction?
All these questions add up to wondering how feasible this product could be for Windsors. As a hobbyist that might get around to making another chair or two this year, spending ~$100 – $200 on this product is about as good a deal as finding a couple good logs for armbows, building a steam box, and the added time that comes with doing all that. I definitely want my own steam box at some point, but right now with three kids under 8 my hobby time is limited and I’m less interested in building shop appliances than actual chairs!
For my other chairs I’ve built, the friend that taught me all this stuff is happy to let me use his steam box, but in the world of social distancing, other options are even more interesting than before.
“You mention not to show this stuff to a power jointer or planer before you dry it. I am wondering, have you carved it with a drawknife when wet, and does it behave similarly to something that is (uh, for lack of a better term?) “traditionally green?” And how about ripping and planing by hand?”
I haven’t used a drawknife on it. My style of chair doesn’t involve much drawknifing. You can rip it by hand, but you need a saw more set up for softwoods because the wet sawdust will quickly fill the gullets of a saw for hardwoods. You can plane it wet, but you need to work across the grain for the most part. The fibers of the boards have been compressed like an accordion. So they are squirrley when wet.
“This is a corollary to the question about carving with a drawknife — is the grain orientation in this stuff as if it were split instead of sawn, so that you have very little short grain and can generally carve in any direction?”
No. There is grain direction. But it’s confused because the fibers have been compressed. So it’s like planing something that is roey and curly…. My advice is to buy a small hunk and play with it. That’s what I did years ago and I learned a lot.
Hope this helps.
I bent some chair crests out of cold-bend hardwood last winter and the squirrely grain was the biggest issue I had to sort out (the bending part was easy). Lacking standing power tools I found I could gently plane cross-grain and then use a coarse grit on my random orbit sander to flatten it. Not my favorite thing; I would rather use green wood, but I have similar problems to yours, storage being the biggest. It works.
Chris, do you have a species you prefer? I tried red oak and was wondering if another species might be less prone to runout.
I’ve used ash, maple, red oak and white oak. They all work fine. Runout is dependent on the individual board you get.
Thanks much, makes perfect sense.
I’ll second that there is definitely grain direction. I used some for a knife block I built. I used a thin piece (1/4 inch thick or so). So the first time I ripped a thin strip off and bent it, and it snapped where the grain ran through. Cut a second piece with the grain and it worked great.
This has to be among the most delightful pictures of Megan ever. She looks like a six-year-old kid with a huge bowl of ice cream. That smile!
I thought the same thing, except a kid with a pretzel hot off the cart, rather than ice cream. Now I want pretzels.
and I want ice cream
Chris, I’ve been interested in trying this stuff since I first heard about it from you. Green hardwoods are unreliable/uncommon where we live. I have held off because I’ve been worried about it “expiring” or drying out before the next project. I know you’re supposed to bag and reseal any extra length you have – have you had any issues with shelf life?
If you keep it wrapped up and sealed, it has an indefinite shelf life. I’ve used stuff that was a year old with no problem. I’ve also thrown scraps in the steambox to see what happens (they become quite flexible and longer…..
Interested to know your kiln setup. Thank you for everything you do in woodworking!
It is a box made from foil-covered insulation board. You can tape it together (we screwed it to a pine frame). The top has a number of holes cut into it to allow moisture to escape. At the bottom are two utility light fixtures with regular bulbs. And we have some stackable wire racks to hold work above the lights. It gets to about 120° (F), which is great for drying wood gently.
I remember you once wrote a blog about a batch of Cold-bent that was “dried on arrival’. Did you ever get a replacement ?
My wife bought me a bit over 100$ of their cold-bent wood for my birthday. When we received the package it was a bunch of dried and brittle wood, absolutely not bendable.
I tried to contact them several time and never had a single answer from them, It’s been almost two years now.
They probably are not concerned about an anonymous woodworker with no blog nor audience getting some expensive firewood…
To this day the package still sit in my shop, expensive and useless… It’s a reminder for me that this company doesn’t stand behind their product.
I’m not Chris but I’ve had some experience with stuff that has dried. I bought some almost 10 years ago, sliced some of it into this strips, used one or two strips on my project, then threw the remaining chunk and a couple strips back in the bag and sealed it. Then waited almost a decade before opening it up again. They were no longer moist, but I wanted to use some of the strips for another project. So I tried two things.
1) I soaked one of the strips and steamed it (In a laughable steaming setup of plastic, tape, and a pot of boiling water) and it bent with no problem.
2) I also tried just soaking a strip and bending it. That worked fine (and was much easier than #1 from a time/setup perspective). Just one caveat is that I don’t really recall how easy it was to bend the stuff in the first place (though I know I could tie it in a knot like Megan in the picture), so I don’t know if it lost some of the flexibility/ease of use.
The steamed wood was easier to bend, but from what I recall that is normal (I also haven’t steamed wood in a decade either). Though the steamed cold-bend wood didn’t require a backing strip to stop splitting on the tension side of the wood (though would probably still be a good idea just to stop the wood from denting), so it didn’t seem to lose the compression advantage compared to normal wood.
I have not tried cutting/shaping the dried out chunk, so I can’t comment on that.
Sorry to hear that. They offered me a refund/replacement.
Thanks for the tips Mark !
I’ll try to soak up a strip this weekend then. That would be a great news if this wood is finally usable.
My collection of Stanley planes date from the 1880s and are not dilettantes, they are working tools long in possession of a laboring family who know making a living at crafts is always a challenge. Thus I am always somewhat ambiguous about your direction in publishing and woodworking, sometimes it is too cuteish/cultish, and by no small measure. The original Arts-n-Crafts crew, on both shores, died from a deep case of commercial impracticality (also, the Hun at the Somme). But, still you can come up with things useful. My Moxon transformed my stock purchase GrizzlyTools bench (with many local mods) in to a wonder of capability. You seem to be kindly to Jim Tolpin, whom we should all venerate. Certainly you have been generous to elderly women.
I have been perfectly content with things flat and square, noticed things with curves, including elderly women, but there is a lot of overhead in all of that. With the info from your post, it seems now that is maybe less so. Perhaps the world is round after all.
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