Why does my bending fail?

[russell lusthaus]

IMO, that is a tight bend for walnut that thick. Laminating it will be easier, for sure. Getting straight grain from end to end is the best place to start troubleshooting. I also agree a bending strap is a good idea, but when I do it, I use a thin strip of hickory as a bending strap. Say like, as wide as my work piece, longer than necessary, and about 1/8 inch thick. I always have Hickory laying around and it is a good tough wood and bends well on its own. Not sure about other woods, but easy enough to try out what you have on hand. Dont use oak or the steam and water may leave stains. I bet ash or maple would work great too. Good Luck

Russ

[Jeff Duncan]

I would question whether you have a lot of stress in that wood already being that it came from a branch and not the trunk? A brand would be under constant tension/compression which may cause problems when trying to bend. For instance if your bending against the way the woods natural tendency is, I would think that would be significantly more difficult to bend than just a straight piece of wood with no pre-existing stress?

Just a though but may be worth trying the same bend with a piece of trunk wood and see if there's any difference?

good luck,
JeffD

[Chris Fournier]

You can easily make the bend that you are proposing but you will need a back strap to prevent the wood from splitting. This being said by the time that you get set up properly to do this you'd be further ahead to use a bent lamination and spring back would be controlled easier as well. Plastic resin glue. Take your time to resaw from a billet and make sure that you put the pieces together in proper sequence from the saw and you will have an almost invisible glue up. Steam bending can do incredible things but you really have to fixture up for success.

[Brian Holcombe]

If you have green lumber available, use that. You can actually use sawn lumber, but you need to align the grain and it's quite wasteful. Probably just as wasteful as riving, but with the price tag of KD sawn lumber on the waste.

I start with rift cut material and cut along the grain lines on both faces, the results are free of grain runout. I do this for most parts (legs, door frames, etc) because the resulting board moves more predictably and I hate the look of boards with runout.

[Frank Drew]

As others have also recommended, I prefer bent laminations for the predictability of the results and they're also easier to do unless you do lots of steam bending and already have your setup.

[Curt Harms]

Certainly no expert on steam bending, but I know cracking like that is probably from grain fibers breaking out because they are not continuous fibers, but rather they'e been cut obliquely through the milling process. Normally you don't care, but when steam bending it can matter. I suspect this is probably species dependent to some degree. You also need a board with straight grain.

Check out Curtis Buchanan on YouTube he makes Windsor chairs. Lots of bending info there. He uses mainly white oak, but I think the principle would apply to any straight grained piece of wood.

One thing I noticed, he rives all his bending wood out of green logs rather than using dimensional lumber. This produces a board with all the long grain fibers running continuous and parallel from one end to the other. Then there is a much better chance of bending without the convex surface fracturing.

I recall a New Yankee Workshop episode where they went to Mike Dunbar's Windsor Chair Institute. Dunbar used all riven stock for steam bending and for the reason stated.