steveJ wrote:

I wonder if the idea of soaking wood before steam bending comes from
trying to bend kiln dried wood by introducing some moisture back into
it.

I suspect so, but it's largely futile for that, too. Aside from the fact
that it doesn't really raise the moisture content, the reason that kiln
dried wood doesn't bend well is because the lignin has be altered by the
heat of the drying process.

Certainly green wood bends easier than kiln dried.

You bet! I haven't noticed too much difference between green and air
dried wood from the same log. They both bend well, though the green wood
seems to require a bit less steaming time to achieve the same result. I
suspect that the extra moisture in the wood transfers the heat more
efficiently to the center of the workpiece (water transfers heat 25x
faster than air).

But I agree, it's
the heat, not the water that allows wood to bend. I've seen dry wood
bent with only heat. Water was used only to keep the wood from scorching.

I know people who've done a lot of dry bending, but I haven't tried it
myself. Compared to steaming, it's harder to achieve an even heat, with
scorching being a common result. I know of one guy who dry bent kiln
dried poplar! While he did manage to get it to bend, the bent parts were
terribly uneven quite charred on the outside. I think he must have been
seriously masochistic!