Stumped By A Kid

the blade is slicing the fibers, and the movement of the blade forward is breaking and pushing them upwards (almost perpendicular to the bevel angle) the thinner the shaving, the less “breakage” and the more of a natural ‘curl’ is formed to the eye.

-- ㊍ When in doubt - There is no doubt - Go the safer route.

If true, I should able to uncurl it make it stay that way. Right? But that’s not the case.

It is an interesting question.
I would need a more detailed sciencetific explanation.
Sorry, I am not offering any. : _(

-- I'll be a woodworker when I grow up. HHHOPKS

The wood is compressed by the cut and because the chisel
bevel forces it to go one way, a little extra compression and
breakage occurs on the opposite side, causing the curl.

I would say it has more to do with stretching the fibers as you cut.

Did you ever see a person gift wrap a package and curl the ribbon by running one side of it against the sharp edge of the scissors? Same principle.

-- Charlie M. "Woodworking - patience = firewood"

hhhopks,

That is exactly what my son and I talked about. The curl is permanent.

Also, what determines the direction of the curling, i.e., clockwise or counterclockwise? Maybe it has to do with the direction that the blade is skewed. If I were in my shop now, I would try skewing in both directions as well as trying to cut with no skew and see if this affects the direction of the corkscrew. I would expect just a coil like a clock spring when cutting without a skew.

-- "Too much hurry ruins the body. I'll sit easy … fan the spark" - I. Anderson

I think it has to do with the Coriolis Effect. Curls will turn the opposite direction south of the equator.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

I’m going with a combination answer – stretching of the fibers from the blade – Charlie’s explanation is an easy way to explain it to an 8 yo. – but if the cut is reasonably thick, then I think there must be some compression too on the top side of the shaving caused by the plane ( or chisel) blade pushing the shaving away from the plane of the surface.

If you take an axe to a tree at an angle, the chip which comes out will be slightly curled – that’s not likely from stretching the fibers.

If you plane endgrain, does it curl?

-- If you can't joint it, bead it!

rance,

That sounds right. Now I remember learning all about this in Earth Science in the 8th grade.

I hope that the Curiosity Rover will be doing some wood curling tests on Mars.

-- "Too much hurry ruins the body. I'll sit easy … fan the spark" - I. Anderson

Chuck, this is what happens when guys our age have young kids.

I’m glad mine are 26 and 23…. they already have ALLthe answers!

-- Charlie M. "Woodworking - patience = firewood"

Wood Fairies !

-- some men see things that are and wonder why, I dream of things that never were and ask why not .... rfk

Smart alec kid. Ban him from the shop. Shouldn’t be askin’ questions that the old man can’t answer.
Just jokin’ of course.
Bill

-- bill@magraphics.us

My chisel shavings never curl. They just come out straight as a board.

Clearly the answer is: you are a wizard.

-- Dan in Minneapolis, woodworking since 11/11.

Chuck, why don’t you tell your son, “It’s natural son. Things happen on their own and they just happen. There’s no need to question them. Just like your hair, it goes curly as it grows longer.” Pretty effective for me. lol

-- "someone has to be wounded for others to be saved, someone has to sacrifice for others to feel happiness, someone has to die so others could live"

Sometimes I think I should be more like the Dad in Calvin and Hobbes

-- "Too much hurry ruins the body. I'll sit easy … fan the spark" - I. Anderson

Not if you don’t have a smart kid like that.

-- "someone has to be wounded for others to be saved, someone has to sacrifice for others to feel happiness, someone has to die so others could live"