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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                                                             
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             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.

------------------------------------------------------------------------

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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