mortise chisel Geometry

[rick bear]

Question, I notice in the Finewoodworking video by Frank Klausz, Chop a Mortise by Hand, that his mortise chisel is tapered; he says this helps to stir the chisel. I notice the Lie-Nielsen mortise chisels are not tapered, parallel sides. How important is this?

Thanks - Rick

http://www.finewoodworking.com/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=26994

[lowell holmes]

The Ashley Iles chisels are tapered. I have both LN and AI mortise chisles. I tend to prefer the AI chisels.

[Johnny Kleso]

For sure I am not a chisel expert but as Frank says you can steer the chisel the LN you can't you have to keep the chisel square at all times but has the plus of punching a parallel groove not a tapered one..

[Chris Fournier]

I saw "stir" in the OP's post and nearly had a heart attack - had I missed a time honoured mortising technique? I admire Franz Klausz after all - far more the guru than the recent Johnny CS Come Lately. Phew, "steer". I have parallel sided mortising chisels and what I like about them is that they take care of business once I set them on their course. There is plenty of opportunity to correct a slighty misguided effort in the initial phases of the mortise - I have to shim all of my tenons anyways!

[Pam Niedermayer]

Yes, "stir" is a peculiar word to use when talking about mortising. My first mortising chisels were western and rectangular. Whether from the shape or my lack of experience, they promptly demonstrated an incredible ability to split wood, pine IIRC, just split, board ruined, and the cheeks were very thick. My next mortisers were Japanese with trapezoidal shape and arrises so sharp I cut my fingers first time out. They are wonderful, the shape helps clear the chips (no levering whatsoever, with either type).

I'd also note that the rectangular chisels were much harder to work, seemed to need much more powerful hitting to make a dent.

Pam

[rick bear]

Thanks for the suggestions. Sorry about steer versus stir - English is not my first language. I'm sure Frank Klausz said steer in his video.

- Rick

[Pam Niedermayer]

Thanks for the suggestions. Sorry about steer versus stir - English is not my first language. I'm sure Frank Klausz said steer in his video.

Not to worry, Rick, "steer" was my interpretation anyhow. I'd watch the video again, but, alas, I only have it on videotape and the VCR is long gone. At any rate, steering a mortising chisel while pounding should not be a goal; but setting it up for accurate cutting to begin with is much more important and useful.

Pam

[Adam Cherubini]

Very important, Rick. I wouldn't consider a mortise chisel that didn't have beveled sides. In fact, I don't care for any chisel that doesn't have this feature. And if you have plane irons that are ground straight, they should have beveled edges too. The issue is that any loss of the corner or any tiny angular steer exposes the thickness of the blade to the wood, resulting in wedging or rubbing.

Adam

[David Weaver]

The Ray Iles chisels are tapered. I have both LN and RI mortise chisles. I tend to prefer the RI chisels.

Me, too. The LN chisels are fine, though - just a bit small. they are very tough for their size and hold their edge very close to as well as the RI chisels, but the pigsticker is nicer to use.

If you're cutting the mortise accurately between your marking lines, you won't have any issues with the straight sides on a LN chisel if you prefer a small sash mortiser to a pigsticker.

[Frank Drew]

I appreciate the benefit to beveled sides, but most important, IMO, for any chisel doing mortising work is that the back not be convex. Any belly makes chopping straight very difficult.

[rick bear]

I'm going to give the Ray Iles - 7/16" a try. Will test it on a Chinese stool project that I've been thinking about for some time; These are the short stools you see throughout the Chinese country side, hand hewn, with mortise legs set at an angle with many variation on the cross supports.

- Rick