are there any decent techniques for squaring a chisel blade?

[Reggie]

BugBear, you're correct, going one further, none of the sharpening tutorials or videos ever show a chisel that isn't square either.

 

[David C]

Reggie,
My chisel sharpening DVD has a specific chapter on squaring chisels.
Unlike Jacob I use specific grinding and honing angles, and a cheap far eastern copy of the Eclipse honing guide.

High finger pressure on one edge and low pressure on the other will bring a chisel towards squareness, with each stroke on a coarse stone.
It is helpful to have access to some kind of grinder.

If so nirvana can be achieved in an afternoon.

www.davidcharlesworth.co.uk

 

[Jacob]

...
Unlike Jacob I use specific grinding and honing angles, and a cheap far eastern copy of the Eclipse honing guide.

Dave I use a specific honing/grinding angle too - 30º as a rule , and <30º to 25º for grinding. What makes you think I don't?

 

[Reggie]

Thanks David C, I'm working on getting access to a grinder, still got to get some bits and bobs, I'm waiting for the toolshow that's relatively close to me next week to see what I can grab.

 

[David C]

With the Derbyshire dip I thought you never needed to grind?

David

 

[Jacob]

With the Derbyshire dip I thought you never needed to grind?

David

It gets deferred - indefinitely for narrow chisels and plane blades, but larger chisels or damaged ones may need a touch up occasionally.

 

[David C]

Exactly. With two bevels the honing area can be kept very narrow. Squaring and sharpening can be done quickly.

Anyway glad I had not imagined it.

David

 

[Jacob]

Exactly. With two bevels the honing area can be kept very narrow. Squaring and sharpening can be done quickly.

Anyway glad I had not imagined it.

David

Exactly what? I do one convex bevel nearly all the time (see PaulSellers video) with a regrind very occasionally - usually if chipped etc. Regrind gives 25º ground flat bevel which is then honed at 30º but dipped as you go, to get back to a rounded bevel. As you dip you catch the edge and the heel and effectively get three bevels, until they join up into one, many honings later.
The 25º hollow ground with 30º "micro" bevel is lazy bad practice IMHO though it does get quick results!

 

[bugbear]

The 25º hollow ground with 30º "micro" bevel is lazy bad practice IMHO though it does get quick results!

New straw man to argue against, Jacob?

The hollow grinding technique uses the same angle for grind and hone, since the honing
angle is set by touching arris and edge to the stone.

You can google for details.

BugBear

 

[G S Haydon]

Why would it be lazy bad practice if it gave quick results?

 

[Graham Orm]

In my opinion it is a better option as it gets more of the chisel out of the way when working, therefore will cut marginally quicker. I hollow grind and micro bevel all my chisels.

 

[Jacob]

Why would it be lazy bad practice if it gave quick results?

You pay for this great thick blade and then set about making it thin so you can hone it easily. :roll: Might as well start with a thin blade.
Even worse hollow grinding a thin blade like a standard plane blade - just makes it fragile. Completely unnecessary.

 

[Jacob]

The 25º hollow ground with 30º "micro" bevel is lazy bad practice IMHO though it does get quick results!

New straw man to argue against, Jacob?

The hollow grinding technique uses the same angle for grind and hone, since the honing
angle is set by touching arris and edge to the stone.

You can google for details.

BugBear

Oh gawd erewego :roll:
Hollow grinding doesn't have a single angle. There is the chord to the perimeter of the grinding circle, which is what you are referring to, but, approaching the edge, the angle of the ground bevel is a tangent to ditto. (As a chord reduces it approaches a tangent) It can even be zero (against the plane of the face) or less than zero, depending on the diameter of the ground circle.

 

[G S Haydon]

Why would it be lazy bad practice if it gave quick results?

You pay for this great thick blade and then set about making it thin so you can hone it easily. :roll: Might as well start with a thin blade.
Even worse hollow grinding a thin blade like a standard plane blade - just makes it fragile. Completely unnecessary.

Not sure the analogy of starting with a thin chisel blade makes total sense. There needs to be enough strength/thickness in the blade to prevent bending in use. I don't see why a hollow grind and hone is so bad if its quick and creates a sharp edge? From my experience the only trouble I find with the convex bevel on chisels is during bevel down work.

 

[Jacob]

..... From my experience the only trouble I find with the convex bevel on chisels is during bevel down work.

That's odd - carvers work bevel down most of the time and prefer convex bevels. A hollow ground bevel with a micro edge would be difficult bevel down - the convexity gives you control.

 

[G S Haydon]

I suppose it depends what your used to. Before making time to get back to woodworking for fun all of my planes and chisels came straight of a tormek. having got used to how this feels a convex bevel felt like a boat on the ocean. I guess I have never done carving and for joinery work the feel of a bevel being planted rather than rocking suits me better. Whatever floats your boat ;-)

 

[David C]

Lazy, bad practice.............., how odd.

Such charming language, for a tradition which goes back hundreds of years. I think there is hardly a manufacturer in the whole of Uk and Europe who does not send out chisels and plane blades ground at 25 degrees.

David

 

[Jacob]

Lazy, bad practice.............., how odd.

Such charming language, for a tradition which goes back hundreds of years. I think there is hardly a manufacturer in the whole of Uk and Europe who does not send out chisels and plane blades ground at 25 degrees.

David

Yes but not hollow ground on a small wheel. Very slightly hollow ground on a big wheel is near enough flat so doesn't count. Small bench grinders are a modern abomination!

 

[G S Haydon]

How modern we talking?

 

[Jacob]

How modern we talking?

Modern in the sense that woodworkers now use them for sharpening. This would have been deprecated not so long ago - strictly a metal worker's tool.