are there any decent techniques for squaring a chisel blade?

[G S Haydon]

Why don't they work on woodworkers tools? Don't you use them on nicked edges or are you lucky enough to have one of the big ol' wheels?

 

[Jacob]

Why don't they work on woodworkers tools?

They do but they hollow grind too much and tend to over heat too easily. It's what we used to do at school and drive the woodwork teacher mad! Bench grinders were in the workshop for the metal workers who shared it.

Don't you use them on nicked edges or are you lucky enough to have one of the big ol' wheels?

No I use a belt sander. Or a coarse stone on smaller blades

 

[Phil Pascoe]

I use 40/60 grit stuck on a ply disc on a lathe faceplate - it works perfectly well, you need to try quite hard to burn anything.

 

[Corneel]

Well, theoretically a concave bevel would be weaker. But in practice, I don't get problems. Rarely do my irons chip at the edges.

Only my jap chisels do I try to keep a flat bevel, because that's the tradition. And if I would do any carving I'd probably be all over convex bevels.

 

[wizard]

If you do not have the skill then by the gadget simples

 

[Jacob]

If you do not have the skill then by the gadget simples

Avoid the gadgets and get more practice in or you will never get it right. Simples. Save the gadgets until you have given up all hope!

 

[bugbear]

No I use a belt sander.

You said you sold the belt sander, and bought a gadget, sorry "Sorby Pro Edge".

BugBear

 

[Sgian Dubh]

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.

I'm another of those (generally) hollow grinder types, with a slightly higher honing angle Jacob. Back in the old days, well when I was young and learning, which I guess is old compared to quite a few here, we just didn't get very fussy about sharpening chisels and plane blades and the like. We had a simple grinding angle and honing angle thing going on -- those angles may have been 25º and 30º, but I don't know for sure as it wasn't something we measured; we simply eyeballed it for 'right'. We used whatever was to hand to create the grinding angle, e.g., bench grindstone, belt sander, linisher, one of those oil drip circular stones that ran flat, and even something like a concrete step or similar if push came to shove, etc. There seems to have been a bit of a fashion developed over the last twenty or so years for 'primary' bevels and 'secondary' bevels... and even something called a 'micro' bevel, which seems to be an additional bevel to the 'secondary' bevel.

To be honest, and it's perhaps because I'm not very frills orientated when it comes to grinding and sharpening, I get a bit lost nowadays with all the chatter that surrounds the 'dark art' of sharpening. Anyway, to the point I was going to make about the challenge of controlling a chisel on the ground face of a hollow grind, if it's been worked up on a regular bench grinder. If need be, I simply take off some the high points at the extremities of the grind on a coarse stone creating a decent what might be called an 'interrupted' flat. It seems to work well enough for bevel down use, even though there is usually a bit of a honing angle to contend with too. I've never noticed that configuration being a problem worth getting excited about anyway. Slainte.

 

[Jacob]

No I use a belt sander.

You said you sold the belt sander, and bought a gadget, sorry "Sorby Pro Edge".

BugBear

The Sorby Pro Edge is a belt sander but designed for sharpening..
An ordinary belt sander will do but not so conveniently and there is a fire risk due to the sparks, dust, and plastic enclosed spaces.

 

[bugbear]

No I use a belt sander.

You said you sold the belt sander, and bought a gadget, sorry "Sorby Pro Edge".

BugBear

The Sorby Pro Edge is a belt sander but designed for sharpening..
An ordinary belt sander will do but not so conveniently and there is a fire risk due to the sparks, dust, and plastic enclosed spaces.

Humpty Dumpty again Jacob?

Horses mouth:

"ProEdge is a revolutionary sharpening system introduced by Robert Sorby."

http://www.robert-sorby.co.uk/proedge.htm

Pricy too, but has nice features:

"The angle setter ensures that the same angle can be achieved accurately time after time."

BugBear

 

[Jacob]

Can't you give it a rest BB? It's boring having you trailing after me with silly comments every time I post. I don't think anybody else is particularly entertained either.
Stop being a troll!

 

[charvercarver]

..... 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.

A bit of rocker is useful, but you still need a fairly abrubt transition from the bevel to the shaft as the high pressure point burnishes the wood after you slice it. I have to say a hollow bevel sounds like a nightmare for a carving chisel, though to be fair I've never used hollow bevels for anything.

 

[MIGNAL]

It's surprising just how easy it is to maintain an angle when freehand sharpening. I recently bought a 6 mm palm chisel but it was ground with a double bevel. Not really what I was after. I decided to grind it down until I had the single bevel of a normal chisel. I did it freehand on a coarse Oil stone. Took a bit of time but I was surprised just how well I maintained the original angle, that bevel ended up pretty flat too. I might employ a slightly different technique to many in that I use a very short forward/backward stroke rather than the long full length strokes done by most woodworkers. I slowly make my way up and down the stone using these short strokes. Seems to work for me.

 

[G S Haydon]

Wow, that sorby concept is quite a thing. Good for a nice flat bevel. I tried a basic bench grinder today to square up an old woodie blade. Seemed to work out ok, made sure I was light with the pressure, cooling as I went at about 25deg the used the oilstone to put on an approx 30 deg angle. The results seemed just fine.

 

[mqbernardo]

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.

Sorry David, but which grit do you use for that? 800 ?

thanks,
Miguel.

 

[David C]

Miguel,

Yes, I use King 800 as my coarse stone.

Any coarse stone grit would do, if you use a finer one it will just take a few more strokes.

David

 

[mqbernardo]

thanks David! That´s what i remembered from the DVD (i have it somewhere, buried under my kids´ DVDs ) - i only have a 800 diamond stone, and was afraid of exerting too much pressure on it - but then i guess my shapton 1000 will do the trick.

Miguel.

 

[David C]

yes 1,000 will do fine.

David

 

[Jacob]

For re-shaping an edge (as per OPs question) I'd use 250 Ezelap diamond (slow) or 80 grit or coarser on a belt sander or flat emery paper - a lot quicker!

 

[Jacob]

Wow, that sorby concept is quite a thing. .....

Dunno it's only a common or garden linisher but adapted slightly for sharpening purposes. Well made though. I only use it with coarser grits for re shaping as I find sharpening easier freehand on flat stones.