A new pig sticker, or the hidden costs of walking to work...

[xy mosian]

Ok! Given the snags to re-forming the edge above. Wouldn't it be wise to start easily rather than to assume that all is well and to belt the living daylights out of the chisel.
Hollow grinding can be avoided, even on small grinding wheels, by grinding across the bevel. Of course you have to watch what is happening.
xy

 

[GazPal]

Ok! Given the snags to re-forming the edge above. Wouldn't it be wise to start easily rather than to assume that all is well and to belt the living daylights out of the chisel.
Hollow grinding can be avoided, even on small grinding wheels, by grinding across the bevel. Of course you have to watch what is happening.
xy

Yes, it's always best to gauge how the blade bites into timber on the first chop/mortise before committing to heavier mallet strikes. That's where technique kicks into gear and potential heartache is greatly reduced.

A genuine drawback with grinding across the bevel is the risk of deforming the edge. One unguarded move and you're back to square one and need to start again.

 

[Vann]

Getting back to Leonard Lee, he recommends a 30° bevel for softwoods and a 35° bevel for hardwoods – but again says “Your guide is edge failure…”

An interesting snippet he includes (I hope I’m not infringing on copyright) refers to Jacob’s obsession...
“The first time I visited the Sorby factory in Sheffield, England, in the 1970s, I asked the works manager why they were the only manufacturer to round the back of the bevel on their mortise chisels. He looked at me quizzically, drew himself up and said something like, “We have been doing that, man and boy, for the 40 years that I’ve worked here.” Although that was not the answer I was looking for, I dropped the subject.
Thinking about it weeks later, after I had returned to Canada, I realized that rounding the junction between the bevel and the blade back would make it easier to lever waste out of a mortise. That particular part of the chisel is used as a fulcrum in the process and rounding it would prevent the corner from digging in.
I should have said something to Sorby at the time because the next year their catalog showed all mortise chisels with a sharp intersection between the bevel and the back. A useful design feature had been lost because nobody knew why it was there.”
The photo accompanying the article shows a slight rounding – not the massive rounding someone on here recommends for all bevels (hammer)

On the subject of secondary bevels on pigstickers, Lee includes a diagram of a chisel with a 35° bevel, and a 25° primary bevel. However he recommends that the secondary bevel should not come closer than 1/8" to the face (measured at 90° to the face, not along the bevel).

Cheers, Vann.

 

[AndyT]

I've had to go quite a long way back to find it, but I'd just like to mention that Eric did say:

"It does have a camber, incidentally, very slightly on the 'reference' face. I can't see it being a problem in use, and I'm not going to mess with it, just sharpen it as-is for now, and see how I go with it."

which seems a sensible approach to me.

 

[GazPal]

On the subject of secondary bevels on pigstickers, Lee includes a diagram of a chisel with a 35° bevel, and a 25° primary bevel. However he recommends that the secondary bevel should not come closer than 1/8" to the face (measured at 90° to the face, not along the bevel).

Cheers, Vann.

I think it can come much closer to the edge than his recommended 1/8", but the meaning behind his figures certainly makes a great deal of sense in terms of blade bevel/tip strength. Secondary bevel angles obviously influence edge retention.

I much prefer rounding the rear primary bevel transition, as it makes this section of the blade less liable to dig into the rear of the cut as you excavate/dig out waste. This method of rounding also helps when the time comes to bottom-out the mortise to a smooth finish.

 

[GazPal]

I've had to go quite a long way back to find it, but I'd just like to mention that Eric did say:

"It does have a camber, incidentally, very slightly on the 'reference' face. I can't see it being a problem in use, and I'm not going to mess with it, just sharpen it as-is for now, and see how I go with it."

which seems a sensible approach to me.

I couldn't agree more Andy

 

[Jacob]

.....
The photo accompanying the article shows a slight rounding – not the massive rounding someone on here recommends for all bevels .....

What on earth is a "massive rounding"? Please explain.
Sorry Gary I don't understand this either "rounding the rear primary bevel transition".??

PS come to think, what is a "slight rounding"? Please explain.

Here's a picture of a rounded bevel on one of mine - a 2 1/2" wide oddity

Is this a "massive" rounding, or a "slight" ditto, and/or where is the "rear primary bevel transition"?

What the f|ck are you all burbling on about?

NB it's sharp with an edge about 30º

 

[GazPal]

.....
The photo accompanying the article shows a slight rounding – not the massive rounding someone on here recommends for all bevels .....

What on earth is a "massive rounding"? Please explain.
Sorry Gary I don't understand this either "rounding the rear primary bevel transition".??

PS come to think, what is a "slight rounding"? Please explain.

Never a problem Jacob. A transition is a point where two different angles or plains meet and smoothly convert from one direction or form to another, so - in this case - that would be the point where the back of the blade meets the rear edge of the primary bevel.

Slight rounding tends to involve a greater arc and radius than if working to a smaller radius which would give a tighter curve/sweep. Two penny round instead of penny round.

Massive rounding is something I've yet to see on a standard straight bladed chisel's bevel. I think you'd need to freehand something like an 87 degree angle - exaggerated for the sake of emphasis - in order to massively round over a bevel.

 

[GazPal]

.....
The photo accompanying the article shows a slight rounding – not the massive rounding someone on here recommends for all bevels .....

What on earth is a "massive rounding"? Please explain.
Sorry Gary I don't understand this either "rounding the rear primary bevel transition".??

PS come to think, what is a "slight rounding"? Please explain.

Here's a picture of a rounded bevel on one of mine - a 2 1/2" wide oddity

Is this a "massive" rounding, or a "slight" ditto, and/or where is the "rear primary bevel transition"?

What the f|ck are you all burbling on about?

NB it's sharp with an edge about 30º

I missed your edit, where you added your picture.

You example shows more a straight transition with a distinct springing point from which the arc of the bevel stems.

The transition point is where the flat plain on the back of your blade meets the point where you'd normally find a primary bevel on a double bevelled edge.

The babbling regards the roundover normally used on mortise chisels Well...... mine does. :lol:

 

[Jacob]

OK so the transition point is where the flat plain on the back of your blade meets the point where you'd normally find a primary bevel on a double bevelled edge.
But this seems to me to be of no interest whatsoever, sharp, massive, angular, rounded, covered in erotic carvings, it has no bearing at all on the sharpness if the chisel.

 

[GazPal]

OK so the transition point is where the flat plain on the back of your blade meets the point where you'd normally find a primary bevel on a double bevelled edge.
But this seems to me to be of no interest whatsoever, sharp, massive, angular, rounded, covered in erotic carvings, it has no bearing at all on the sharpness if the chisel.

Sharpness wasn't the point (Pardon the accidental pun) when mentioning the roundover at the rear of the bevel on mortise chisel. It regarded the manner in which such a roundover can aid chisel work when mortising.

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

I'd never called or known heavy duty mortise chisel were nicknamed "pig stickers" until I began visiting online woodworking fora, so assume it must be yet another "Americanism". Bayonets..... yes, but never chisels. :lol:

 

[Jacob]

...
I'd never called or known heavy duty mortise chisel were nicknamed "pig stickers" until I began visiting online woodworking fora, s .....

Me too. I think it was invented on this forum, possibly along with "OBM" for "oval bolster" mortice chisel

 

[bugbear]

...
I'd never called or known heavy duty mortise chisel were nicknamed "pig stickers" until I began visiting online woodworking fora, s .....

Me too. I think it was invented on this forum

You are wrong, as a simple search would have shown you.

BugBear

 

[Harbo]

http://www.wkfinetools.com/contrib/cSch ... tChis1.asp

Rod

 

[Jacob]

He probably picked it up from this forum.

 

[Racers]

33,900 results from a google search for "pigsticker chisel", they have learnt allot from us ;-)

Pete

 

[Eric The Viking]

The really creepy thing about that chap staring at the back of my neck is that, as soon as I turn round...

... he isn't.

Fiendishly cunning.

:duno: E.

PS: didn't mean anything disparaging by 'pigsticker' anyway. I'd far rather live in a world where that was the normal thing to do* when you wanted bacon, than one in which it's politically incorrect to even smell the stuff.

*possibly with a different tool, though.

 

[AndyT]

When I Googled "pig stickers" I got this!

Am I doing something wrong? :roll:

 

[Racers]

Pete

 

[Jacob]

33,900 results from a google search for "pigsticker chisel", they have learnt allot from us ;-)

Pete

851000 hits on "twerp"! That's interesting isn't it!