sharpening technique

[Trafalgar]

The answer is too obvious, and not relevant to the majority of cabinetmaking sharpening, (chisels and plane blades).

I am not a carver, and have very occasionally used in cannel gouges.

These were sharpened with a flat stone and some slipstones. How else?

David

So you have no trouble with it?

And router planes, molding planes, marking knifes, drawknifes, skewed irons, German scrub planes and everything else. And each one of them is just a little or quite a bit more difficult then chisels and planeblades. Combine that with the freedom aquired with freehand sharpening, the speed and the better use of the stone surface, and you'll have to confess that freehand sharpening is the more rational method.

All the difficulties with freehand honing chisels and plane irons is obviated by simply honing on the grinding angle. The cutter clicks, toe and heel, registration is positive - as positive as using a jig. When the hollow gets a little small, just refresh it. Unless nicked, the grinding wheel should never shorten a cutter. If a burr is being produced at the grinding wheel it's being used incorrectly (except in the case where a nick is being worked out).

Jacob's method works exceptionally well too.

 

[Sgian Dubh]

Thinking of doing spindly little cabinets with flared legs - came to me in a dream.

Market them as made by Krakob Jenov. They could go down a storm, or maybe just go down, ha, ha. Slainte.

 

[jamesicus]

.......... Thanks James .......... My little theory, the grindstone would have been used only once a week or so, not on a daily basis. And most workmen would try to keep the bevel straight but ended up with a bit of convexity anyway ...........

Thanks Corneel. Your observations are pretty much correct - as I remember.

.......... I wonder, would you remove the 35 degree sec. bevel on each sharpening again? Start over fresh so to say? ..........

As I remember, we only "freshed up" the bevel on subsequent grindstone treatments - but I am not dead certain about that -I haven't used a grindstone in this manner for many years.

 

[jamesicus]

.......... Excessive use of the grindstone was regarded as cheating and was reserved for major remedial work only ...........

That is pretty much the way I considered it, Jacob.

 

[bugbear]

...... I wonder, would you remove the 35 degree sec. bevel on each sharpening again? Start over fresh so to say? ..........

As I remember, we only "freshed up" the bevel on subsequent grindstone treatments - but I am not dead certain about that -I haven't used a grindstone in this manner for many years.

That would make perfect sense - leaving a "sliver of the old secondary bevel" as Paul Chapman put it recently.

BugBear

 

[Jacob]

.......

All the difficulties with freehand honing chisels and plane irons is obviated by simply honing on the grinding angle. The cutter clicks, toe and heel, registration is positive - as positive as using a jig. When the hollow gets a little small, just refresh it. ......

Well yes that makes sense, except that to hollow grind in such a way that the heel and toe are exactly on a specific line would need a very controlled operation to get the geometry right. How is this done? Then when it is done how do you control the freehand honing to maintain the angle, without taking more of either the toe or the heel?
Sounds very much like the logic of the new sharpeners - i.e. logical but not necessarily practical.
IMHO in the end in comes down to hand and eye judgement of the angle - that thing which the new sharpeners say is difficult/impossible. Luckily they are utterly wrong!

....Unless nicked, the grinding wheel should never shorten a cutter. If a burr is being produced at the grinding wheel it's being used incorrectly (except in the case where a nick is being worked out).....

I use belt sander if necessary and always remove the whole bevel including generating a burr. This might mean having to straighten up the edge by applying it at 90º, but the whole point it to get past the wear on both sides of the bevel. If you are using a machine you might as well use it, rather than leaving a bit to be done laboriously by hand.

PS obviously one hits an angle with heel and toe, but one doesn't know what it is unless measured or created with some clever jig. I think it is probably corrected unconciously, by hand and eye skill.

 

[Racers]

Some sort of rest on the grind stone would probably do it easily.

Pete

 

[Jacob]

Some sort of rest on the grind stone would probably do it easily.

Pete

Yes, but not easily. The geometry of each thickness of blade would be different for starters.
My feeling is that people imagine they are relying on a machine or jig set up but are in fact also using hand and eye skills, however much they say they can't do it!

 

[Corneel]

I use the toolrest from the grinder to establish the concavity. I peek from the side if the grinding wheel touches the bevel somewhere in the middle, tap the toolrest a little higher or lower if neccessary with a hammer (no fiddling around with the bolts). Then I grind until just before raising a wire edge. Then onto a 400 stone where I raise a sizeable wire with very few strokes. Continue onto the finer stones. I have a very good reason not to raise a wireedge on the grinder. Somehow the grinding process becomes very slow when you're almost there. Further grinding by hand on a coarse flat stone is quicker, probably because you only remove a little bit of steel.

Working on the flat stone is very easy. Rest the bevel on the stone, keep your elbows locked and move the iron back and forth vigourously, until you can feel the wireedge. That's really all there is to it. :lol:

On the polishing stone I polish the bevel first a bit. Then raise the iron a few degrees and do two more stokes, just to be sure I am really polishing right at the edge. Not more, because when you do too much it hounds you on the next sharpening when it becomes tedious to remove enough metal again to raise a wire edge on the coarser stone.

All this works very well, but it has one disadvantage: you need to use the grinder quite often, which I think slows me down too much.

 

[MIGNAL]

I used to hollow grind on a hand crank grinder. To re-establish the bevel I would creep up until just a glint of polished steel was showing at the very tip. Easy to do on a hand crank and less danger of overheating the steel. I think the wheel was 100G. I would go straight from the hand crank to an 8,000G waterstone, nothing between the two grits. Simply isn't necessary.
Freehand on a hollow grind is really easy. It registers very positively on the stone. Material is removed from both the tip and the back of the hollow grind.
Now I only use the hand crank for damaged blades. I use a medium stone and the 8,000G. No hollow grind but two bevels. Freehand in short forward/backward strokes, slowly creeping to the middle of the stone and back. I only use half the length of the stone but I do try to keep things random. I don't think my primary bevel is perfectly flat but it's near enough.

 

[CHJ]

I use the toolrest from the grinder to establish the concavity. I peek from the side if the grinding wheel touches the bevel somewhere in the middle, tap the toolrest a little higher or lower if neccessary with a hammer (no fiddling around with the bolts). Then I grind until just before raising a wire edge. Then onto a 400 stone where I raise a sizeable wire with very few strokes. Continue onto the finer stones. I have a very good reason not to raise a wireedge on the grinder. Somehow the grinding process becomes very slow when you're almost there. Further grinding by hand on a coarse flat stone is quicker, probably because you only remove a little bit of steel.
......

If your basic angle is always the same it might be easier to set the rest with a template, easier to eyeball.

 

[Zeddedhed]

I use a Tormek.....

 

[Graham Orm]

I use a Tormek.....

I'd use one as well........if I could get someone to give me one............a Tormek that is (leave it!)

 

[Corneel]

If your basic angle is always the same it might be easier to set the rest with a template, easier to eyeball.

When you want to establish a specific angle that is a good idea. But when you are merely maintaning the existing angle, the existing bevel is allready a template.

 

[Zeddedhed]

I use a Tormek.....

I'd use one as well........if I could get someone to give me one............a Tormek that is (leave it!)

They're absolutely fantastic tools. I hate sharpening, but love sharp things. The Tormek lets me get the job done in a relatively short time and the edge it gives is good enough for the work I do. When working away from the workshop I use a diamond stone in emergencies but don't really have the confidence to do regular freehand sharpening, and to be honest there are other things I'd rather invest my time in practising (like how to set up my cheap and nasty Irwin spokeshave!!)

That said it is fun watching everyone getting so irate about their own preferred method of sharpening. It would appear that for some sharpening is more akin to a religion. Ho hum.

 

[Corneel]

Some sort of rest on the grind stone would probably do it easily.

Pete

Yes, but not easily. The geometry of each thickness of blade would be different for starters.
My feeling is that people imagine they are relying on a machine or jig set up but are in fact also using hand and eye skills, however much they say they can't do it!

Yes, that's how it works more or less. Look at it, does it look 25-ish? Then continue, else set the tool rest a bit steeper or lower. If I want to know what I end up with, I'll meassure the angle.

 

[Trafalgar]

.......

All the difficulties with freehand honing chisels and plane irons is obviated by simply honing on the grinding angle. The cutter clicks, toe and heel, registration is positive - as positive as using a jig. When the hollow gets a little small, just refresh it. ......

Well yes that makes sense, except that to hollow grind in such a way that the heel and toe are exactly on a specific line would need a very controlled operation to get the geometry right. How is this done? Then when it is done how do you control the freehand honing to maintain the angle, without taking more of either the toe or the heel?
Sounds very much like the logic of the new sharpeners - i.e. logical but not necessarily practical.
IMHO in the end in comes down to hand and eye judgement of the angle - that thing which the new sharpeners say is difficult/impossible. Luckily they are utterly wrong!

....Unless nicked, the grinding wheel should never shorten a cutter. If a burr is being produced at the grinding wheel it's being used incorrectly (except in the case where a nick is being worked out).....

I use belt sander if necessary and always remove the whole bevel including generating a burr. This might mean having to straighten up the edge by applying it at 90º, but the whole point it to get past the wear on both sides of the bevel. If you are using a machine you might as well use it, rather than leaving a bit to be done laboriously by hand.

PS obviously one hits an angle with heel and toe, but one doesn't know what it is unless measured or created with some clever jig. I think it is probably corrected unconciously, by hand and eye skill.

It can become a bit like contemplating the hydraulics associated with urinating -- think about it too much and you'll never whiz again.

I eyeball the cutter from the side, burp the grinder (flip it on and off), advance the cutter and let the dying wheel make its mark to see if it'll hit dead center of small, but existing hollow grind. Make small adjustment to rest if necessary, turn grinder on, produce hollow grind not quite to the edge, hone cutter at the grinding angle (using the hollow as a jig) on a Washita then Black Ark.

Folks who grind at 25* then lift and hone at 30* without 'rounding under' the bevel as your method does are usually blunting the cutter or raising the angle inadvertently too high over several honings, resulting in trying to pare, for instance, with a 35*+ chisel -- pure silliness.

Charles

 

[Carl P]

[/quote]

It can become a bit like contemplating the hydraulics associated with urinating -- think about it too much and you'll never whiz again.

[/quote]


Thank you very much for this, every bit as good as your definition of flatness - something worthwhile from a sharpening thread!

Cheerio,

Carl

 

[Jacob]

.....
It can become a bit like contemplating the hydraulics associated with urinating -- think about it too much and you'll never whiz again.
.....

Absolutely.
Ideally, sharpening is just something you do a little and often, without giving it a thought. Head down, brain off, every time!