OldTools Archive
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164471 | "Frank Filippone" <red735i@e...> | 2006‑11‑01 | Mortise chisel angles.... |
I notice a lot of the older pig sticker type mortise chisels ( on that auction site) have rather sharp points ( angle of sharpening). A lot sharper that I thought would be used. Does anyone have a few around that can measure the angle and report back? Is there some literature that recommends, to the student or professional, the "proper" angle of sharpening? Frank Filippone red735i@e... ------------------------------------------------------------------------ |
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164479 | "Ken Greenberg" <ken@c...> | 2006‑11‑01 | Re: Mortise chisel angles.... |
On 1 Nov 2006 at 6:47, Frank Filippone wrote: > I notice a lot of the older pig sticker type mortise chisels ( on that > auction site) have rather sharp points ( angle of sharpening). A lot > sharper that I thought would be used. Does anyone have a few around > that can measure the angle and report back? Is there some literature > that recommends, to the student or professional, the "proper" angle of > sharpening? Leonard Lee's book ("The Complete Guide to Sharpening") recommends a 30 degree bevel for softwoods and a 35 degree bevel for hardwoods. Since I generally follow his advice, that's what I teach in my sharpening classes and that's the way I sharpen all my mortise chisels. -Ken Ken Greenberg (ken@c...) 667 Brush Creek Rd., Santa Rosa, CA 95404 http://www.calast.com/personal/ken/wood.htm Visit the oldtools book list at http://www.calast.com/personal/ken/booklist.htm ------------------------------------------------------------------------ |
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164478 | "Ted Shuck" <ted.shuck@g...> | 2006‑11‑01 | Re: Mortise chisel angles.... |
Frank asked about chisel bevel angles: Is there some literature that recommends, to the student or professional, the "proper" angle of sharpening? Don't know about any literature, but I did pick up some tidbits from a discussion in another group on this subject a while back. From what I remember..., the seemingly learned opinion on the subject was that a low primary bevel angle of about 20 degrees was appropriate to allow the bevel to be more easily driven into the mortise. A higher secondary bevel of around 30-35 degrees was suggested to retain the edge. A convex grind (opposite of hollow grind) was recommended to help move the chips and keep the chisel from sticking in the cut. I've found that it does help to speed chopping to have the low primary bevel and that the rounded transition to the secondary bevel seems to make the chip clearing work better. Best Regards, Ted ------------------------------------------------------------------------ |
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164474 | dcarr10760@a... | 2006‑11‑01 | Re: Mortise chisel angles.... |
Frank Filippone wrote: >I notice a lot of the older pig sticker type mortise chisels ( on that auction >site) have rather sharp points ( angle of >sharpening). A lot sharper that I thought would be used. Does anyone have a >few around that can measure the angle and report back? >Is there some literature that recommends, to the student or professional, the >"proper" angle of sharpening? In the set of oval bolstered pig stickers I just got as part of the chest mentioned in my saw nib post, the grinding angle is very low. I'm not home so I cannot measure them, but a pic is here: http://www.wdynamic.com/galoots/4images/details.php?image_id=5071 The arris between bevel and top has been intentially and skillfully radiused. This is the case also with the bench chisels (low angle also). I'll measure the angle when I get home tonite. Best Regards, David C. ------------------------------------------------------------------------ |
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164482 | jwpopp <jwpopp@p...> | 2006‑11‑01 | Re: Mortise chisel angles.... |
Gentle Galoots - Not a rant, but a suggestion that we recall, IMHO, that woodworking is more art than science. There is really no "correct" angle for a mortising chisel, save that which works best for you. There's a probable range - e.g., 20 to 40 degrees. No apoplexy among the purists, please - hear me out before sharpening the rope. I admit to having been guilty of repeating the commonly held mantra requiring that mortise chisels be sharpened steeply - at perhaps 35-40 deg plus secondary - so as to withstand the rigors of such brutal work. "There's the right way t' go f'yer mate - make 'er plenty stout" ... and harder to beat to depth, too. In truth, craftsmen (persons? - there's no innate gender specificity in my thoughts about this or much of anything) approach many differing materials, with widely differing levels of imposed force, and with varying qualities of chisels. Steel has improved immensely in quality, and even a low-born chisel (with a blue handle, eh?) is likely to perform surprisingly well. The person expertly flailing away trying to make a living at it will work differently from most amateurs. Who's actually turned an edge? Broken off a bevel? If you're not experiencing problems with the tool as used in your hands, then the shallowest successful angle is right for you, and will work the most easily. Sharpness is likely to have more influence than bevel angle. I'm not so sure that convex radiusing is a convincing argument. Concave (hollow ground) should release even more easily because relative angle will cause bevel to back away from wood faster upon retraction and leave more room for springback of compressed fibers, but that of course weakens the edge. Release should perhaps then be considered to have been harmoniously optimized with bevel strength in a flat-ground configuration . A convex radius in extremis seems more to me like approaching the cut with a branding iron. That's yet another challenge - the added stength of a flat grind over a hollow grind is technically inarguable, but I'll bet that most of those who hollow grind don't have a vexing problem with breakage ... eh?? All that said, the true old pros who were working oak with biceps larger than two of our legs, cask-sized mauls, and older steel needed pretty stout chisels, with the modern lesson devolving finally to a suggestion to increase the bevel angle as increased skill, confidence, and energy begin to yield tool damage. (Uhhhh - yup, I exaggerated, but the point remains.) Let the tool tell you - if it's happy, then be happy right along with it. If it's requiring a good honing every whipstitch, try a steeper and broader secondary as a trial, then evaluate - is it angle or steel quality? (BTW - and again IMHO - chisel steel should be in the range of 58-62 Rockwell C and fine-grained. Needs to be able to take a scary-sharp edge, take a honing readily, not edge-turn in the work, and not be breaking off under lateral stress.) ... and "sharp" is the keyword. Once, after acquiring a new mortising chisel, I was disappointed to discover that it sported only a 25 degree bevel. Haven't damaged it yet (and I'm not shy about smacking a chisel, either!), so I'm happy and better educated for the experience. (I could probably damage it in ironwood or ebony, but haven't yet tried that - too expensive for casual experimentation.) Added a 35 degree secondary as I learned more, and happily keep it lethal with not much effort via a hunk of glass and some wet-or-dry. Keep yer tote tight, ---John ------------------------------------------------------ JWPopp "Poppajohn" (jwpopp@p...) ------------------------------------------------------------------------ |
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164486 | gmaze@s... | 2006‑11‑01 | Re: Mortise chisel angles.... |
David, I think you owe me a new keyboard!! Post a warning before you put tool porn up like that.... I have been wanting to build a jointers chest like that for a while, but could not find good pictures of the interior of a nice one. Thanks for the pix. I especially like the idea behind the converted saw till. Gary Maze Who saw his first morticing chisel in the wild and was going to buy it until picking it up noticed the previous owner thought the bevel was too steep and put a nice 10 degree back bevel on it, *sigh* dcarr10760@a... m Sent by: To oldtools-bounces@ red735i@e..., ruckus.law.cornel oldtools@r... l.edu cc Subject 11/01/2006 10:58 Re: [OldTools] Mortise chisel AM angles.... Frank Filippone wrote: >I notice a lot of the older pig sticker type mortise chisels ( on that auction >site) have rather sharp points ( angle of >sharpening). A lot sharper that I thought would be used. Does anyone have a >few around that can measure the angle and report back? >Is there some literature that recommends, to the student or professional, the >"proper" angle of sharpening? In the set of oval bolstered pig stickers I just got as part of the chest mentioned in my saw nib post, the grinding angle is very low. I'm not home so I cannot measure them, but a pic is here: http://www.wdynamic.com/galoots/4images/details.php?image_id=5071 The arris between bevel and top has been intentially and skillfully radiused. This is the case also with the bench chisels (low angle also). I'll measure the angle when I get home tonite. Best Regards, David C. ------------------------------------------------------------------------ |
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164496 | Michele Minch <ruby@m...> | 2006‑11‑01 | Re: Mortise chisel angles.... |
Frank Filippone wrote: > Does anyone have a few around that can measure the angle and > report back? > Is there some literature that recommends, to the student or > professional, the "proper" angle of sharpening? GGG FWIW - I have 7 remaining pigstickers from a group that I picked up in a junk shop in Italy last year. 6 are Goldenberg chisels 1/2 and 5/8" (or metric equivalent) and one is not marked except for "cast steel" and "3/8". They are all new and have never had handles on them, and the factory grinds have never been honed. 1 (the "cast Steel") is at 20° 4 are at 25° 2 are at 30°S so the answer is, as the answer to many things in life is, "it depends". Ed Minch ------------------------------------------------------------------------ |
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164502 | DCarr10760@a... | 2006‑11‑01 | Re: Mortise chisel angles.... |
Frank and All GG, I measured my set of pigstickers and they are generally around 20 - 25 degrees. Interestingly, the narrower ones had more acute angles nearer to 20 degree end and the wider ones closer to 25 and even above. Only one or two have secondary bevels. David C. ------------------------------------------------------------------------ |
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164477 | "Derek Cohen" <derekcohen@i...> | 2006‑11‑02 | Re: Mortise chisel angles.... |
Frank asked |
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