picking up the gauntlet!! Bending wood part1 of several

[smitty10101]

Ok ---since someone threw down the gauntlet--https://www.workersofwood.com/viewtopic.php?f=4&t=613
I'll accept the challenge.

let's talk about bending wood---keeping in mind that someday someone may stumble upon this topic and have zero knowledge on the subject.

Questions:

Why do we steam wood prior to bending it??
To the uninformed, it would seem that introducing water back into the wood would allow some flexibility to allow it to be bent.
So what does introducing steam into the process accomplish?
Why doesn't rehydrating with cold water accomplish our goal?

To be continued.

Do you have a preferred steaming apparatus that you use?
Homemade? Store-Bought?
How are you generating the steam? Kettle? wallpaper steamer?

[Cherryville Chuck]

I tried it in a very crude way a few years back when I was trying to build lazy susans for my corner cupboards and I wanted to put a wood rim around them. The reason why is to soften the lignins in the wood. Lignins are essentially a plastic. They were experimenting here with making car fenders out of them at one time. I read years ago too that the Japanese were taking some of the logs we were exporting to them (and it was lots) and on the trip over, which took about a week, they were squeezing the logs square with heat (probably steam) and pressure so that there would no sawing losses. It probably didn't prove to be viable as I haven't heard of that since. Once heated they can be reformed and will retain most of the bend.

You can use just hot water too but it takes longer for the wood to dry out after and you have to be able to immerse the wood in the container. If the pieces are large it's more practical to build a box or find a pipe that the wood will fit in and steam them. Steam also carries more heat energy too even though the steam may be 212F/100C and so is the water. There's a complicated explanation as to why but it makes the steam more effective.

I tried bending red oak just holding it over a steaming pot and it didn't work that well. The strips were about 1/4" thick. I finally threw the strips away last year but they still had the bend in them. In the end I cut the strips thinner out of pine and clamped a set of rounded cauls to bend and hold them in place.

You can learn quite a bit about bending by going through Lee Valley's catalogue and seeing what they have for doing it and reading the explanations for why you use the items. Bending thicker material is trickier. The general rule for steaming the wood is one hour of steaming per inch of thickness. I'm pretty sure from what I've read and watched that bending anything 1" or thicker is more than a one person job.

[Cherryville Chuck]

I've been slowly reading my latest issue of Fine Woodworking (Jan/Feb 2021 #287) and near the back is an article by chair maker Brian Boggs on bending wood which is pretty good. He also list various woods he uses and how they rate for bending. One thing I did not know is that there are many hickory subspecies. I knew there were in oak, maple, and pines but I wasn't aware of that being true about hickory. Unless you bought directly from the mill that cut it you would probably never know or be able to find out which one. He said some work very well and some are impossible.

Also in that issue is a picture of one of their other contributors with what looks like a long skinny steel tool box sitting on a two burner electric hot plate. He must just put water in the bottom and turn on the heat and shut the lid.

[Bushwhacker]

Several months ago. I attempted to make a stand up lamp. I used cedar for the softness of it. I glued up and cut out three disc 9", 10", and 12".
These were to become the separate levels of the lamp. the smallest at the top and the largest at the bottom. I cut a 3/4 x 3/4 chunk out of each disc at three equal points around the disc. I then inserted a 4 foot 3/4 x 3/4 strip of cedar in each disc. making a sort of a cylinder with the large disc at one end and the smallest at the other and spaced the mid sized disc 18 inches from the small top disc.

I had an old 10 inch wooden cylinder, ( a piece of a wooden column I had left from a job). I cut a 5 foot piece of it.
I covered my work bench with a sheet of butcher paper.
I laid the wooden cylinder on the edge of the paper. I then laid a piece of wood along one side of the cylinder, then following edge of the piece of wood I marked a line from the top of the cylinder to the bottom.

I then laid the cylinder on the paper so the pencil line was down against the left edge of my paper.
I marked the paper where the pencil mark touched at the top end. Then rolled the cylinder until the pencil mark retouched the paper. Then marked the paper where the pencil mark touched lower edge of the paper.

Then by connecting the two marks, I drew a line from one to the other. This gave me a diagonal line across the sheet of butcher paper.

I cut of my paper along the diagonal line . This made a right triangle as long as my cylinder
I taped the left edge of the right triangle to the straight line drawn on the cylinder, then smoothed the right side of the triangle around the cylinder from the top to the bottom.
Then I taped that edge down .
I then cut several 1/8 th inch strips of cedar 5 foot long by 1 1/2 inch wide and glued them into three bundles equal to 3/4 inches thick.
I immediately clamped one end of the wooden strips to the top of the cylinder, then wrapping the bundle of strips around the cylinder ( following the curved right edge of the tape,) I clamped the other end to the bottom of the cylinder.
I used several larger clamps to get the twisted bundle of strips as close to flat against the cylinder as possible.

Since the glue was still wet, this allowed the 1/8 inch strips to slide a bit to conform to the twist around the cylinder.

This was allowed to dry for several days.
I made three of these.

I have attempted several times to attach this twisted strip to the wooden frame of the lamp, but it would not come out even with all three strips attached.
Plus if you force it against the frame of the lamp, it causes the whole lamp to lean either one way of the other.
I reclamped all three strips to the cylinder, where they have been for several months.

I have the rest of the lamp wired and sitting in a corner. Waiting for me to try to attach all of it together.
Which I may or may not do one of these days.

That is my experience with attempting to twist wood.

Bushwhacker

[Cherryville Chuck]

I think your only option now David would be to put a shim in between any gaps. I never know when someone back east says cedar whether they mean western red cedar or aromatic cedar which is what we would call juniper although juniper might be a sub species related to aromatic. WRC bends really well especially if it is clear old growth. You can take a 4' piece of it and bend it around and touch the tips together without heat or steam as long as it is no more than about 1/8" thick and straight grained.

Trying to get it perfectly conformed to a shape might still be a challenge. The only ways I found that bending like that worked was bending it around a form and then clamping a caul against it with the same shape. I see in some of the bending literature I've read that the pros do the same thing, either put the pieces between two form or one form and a series of smaller cauls to make small sections conform to the shape. In your case maybe using inner tube for clamps might have worked better. If you went to a tire shop and got some old ones and spiral ripped them into a long strip then that might work when wrapping around the column you used. Alternatively a whole bunch of ratchet straps might have worked too. All the experts say they bend to a little more curve than they want as there is always a little spring back once you release the clamps.

[Bushwhacker]

The inner tubes or ratchet straps probably would have worked better then the wood clamps. It was difficult keeping them tight on a round cylinder.
Not sure where the Cedar came from, it did smell like cedar .
Once it warms up a bit around here, I plan to take them off the clamps , where they have been for several months now. And see if I can do some thing with them.
I have some pictures around some place, I'll have to ask Sandra about that. If I find them we will post some to show how they were made. and may give you a better idea of what I was attempting.

Thanks for the advise and the help.

Stay safe my friend.

Bushwhacker (David)