Chisel primary bevel sharpening.

[Bluekingfisher]

while perusing the Tube last evening I ended up watching several vidoes by accomplished woodworkers on 'how to sharpen a chisel'

What was apparent was most sharpened free hand ( not surprising) however, several of them sharpened the chisel only on the primary bevel i.e no micro or secondary bevel created.

Are there advantages/disadvantages to this. The main advantage I suspect is not having to regrind as the primary as it will remain constant.

Anything else I am missing? and does anyone else sharpen this way?

David

 

[YorkshireMartin]

I only have a primary bevel on mine, but I'm very new to this so I can't give a particular reason. It's just how they came and I sharpened them at their original bevel angle of 25deg.

They are extremely sharp, so I've not felt the need to explore a secondary bevel or micro bevel yet.

 

[DTR]

A coarse abrasive removes material quickly but doesn't leave a good edge.
A fine abrasive leaves a good edge but removes material slowly.
Using a small secondary bevel is the best of both worlds. Because it is a small area, the secondary bevel can be honed quickly with a fine abrasive. Trying to hone the entire bevel with the fine abrasive would take far longer* (and is also a bit of a waste, as the the finish on the area behind the bevel is irrelevant).

I can't see much advantage to using a single bevel, unless it is Jacob's rounded bevel where only the tip needs to be honed. But then, that's just the same theory as a secondary bevel, just without a clear boundary between the two bevels.

* of course, if the entire bevel is only a small bevel anyway, say on a 1/4" chisel, then you don't waste any time by honing the entire bevel.

 

[matthewwh]

Hi David,

Two different techniques, with plusses and minuses for each.

Freehanding on diamond or oilstones you work the full bevel and the natural curvature of your stroke produces a slightly steeper angle at the edge. Ideal for situations where you travel to the job, less stuff to lose / find etc. If possible always try to have the stone at the same height and distance from your body, .

Guided honing on waterstones or films, you isolate very small surfaces and polish them very precisely with a small number of deliberate strokes. Ideal for workshop based situations, finer work and more challenging timbers, where very sharp edges are sometimes required.

The problems and frustrations usually arise when people try to mix the materials and methods inappropriately.

 

[bugbear]

I can't see much advantage to using a single bevel, unless it is Jacob's rounded bevel where only the tip needs to be honed. But then, that's just the same theory as a secondary bevel, just without a clear boundary between the two bevels.

No. As I understand it, Jacob works the whole of his rounded bevel, not just the tip. It really is a single bevel (or infinite )

BugBear

 

[DTR]

I can't see much advantage to using a single bevel, unless it is Jacob's rounded bevel where only the tip needs to be honed. But then, that's just the same theory as a secondary bevel, just without a clear boundary between the two bevels.

No. As I understand it, Jacob works the whole of his rounded bevel, not just the tip. It really is a single bevel (or infinite )

BugBear

Ok, I'll duck out now before this turns into one of "those" threads :shock:

 

[matthewwh]

Pass the popcorn Dave!

 

[Derek Cohen (Perth Oz)]

while perusing the Tube last evening I ended up watching several vidoes by accomplished woodworkers on 'how to sharpen a chisel'

What was apparent was most sharpened free hand ( not surprising) however, several of them sharpened the chisel only on the primary bevel i.e no micro or secondary bevel created.

Are there advantages/disadvantages to this. The main advantage I suspect is not having to regrind as the primary as it will remain constant.

Anything else I am missing? and does anyone else sharpen this way?

David

Hi David

A sharpening question?! You are a naughty boy! Now Charles will disagree with me, and Jacob will disagree with everyone ... :lol:

I grind a full hollow - right to the edge of the blade. Then I freehand hone on the hollow, using it as a jig.

This method is not advisable for many and only works under certain conditions. It is risky, because without the right gear you will burn the edge of the blade, or wear away the steel more quickly. On the other hand, if you can grind the hollow to the edge without heating the steel, and the hollow is smooth(ish) and leaves behind a straight (unrough) edge, then you can be onto a really fast sharpening system.

There are only two ways to grind like this: either use a Tormek wet grinder (220 grit) or a CBN wheel on a dry grinder (mine is 180 grit). These grinders are so controllable that you can work to the edge and stop just as you begin to feel the merest wire edge - which actually uses the same mount of steel as honing. But the real benefit comes from the ease of honing after this.

The advantage of this type of grinding is that you do very little grinding thereafter. The resulting microbevel from honing starts off so small that it takes a long time to be large enough to grind again. So lots of money spent on a system that gets relatively little use! But you did not ask about cost.

System here: http://www.inthewoodshop.com/WoodworkTe ... SetUp.html

Regards from Perth

Derek

 

[Corneel]

An advantage of a flat primary and honing on the same angle is that it looks nice. On Japanese tools that is a factor of some importance.

 

[Bluekingfisher]

Thanks everyone for their response, very useful as always.

I know sharpening is a contentious subject although I promise I was not intending to provoke

I have been experiencing fantastic results with diamond plates achieving a consistent edge enough to shave my arm. However, I was honing the edge on a Veritas MKII guide, which despite being accurate and consistent seemed to be taking a fair amount of metal off each time I honed. So, Derek your timely input has been invaluable at this point. I recently invested in Tormek T7. I have been using it to create the primary (using the 220 grit only) Then trying my hand at free hand honing of the micro bevel purely 1. To experience how to free hand hone consistently and 2. To reduce the extra little time fiddling with the MKII. I have been acheiving decent results, though perhaps not so keen an edge when using the guide, practice makes perfect I am hoping.

I have a question regards your technique, do you create the edge by simply placing thehollowed bevel on the sharpening plate/stone and use the top and bottom of the bevel as the 'guide' to create the edge or do you lift the bevel slightly so only the leading edge contacts the stone?

I'll check out your link for further investigation.

Thanks again all.

David

 

[JonnyW]

I remember seeing either the same videos or similar David, when I was researching sharpening methods. I was still trying to get my head around grinding the primary, then using my MKII to hone the micro bevel. I thought at one point that I was to hone the primary.

I have noticed the MKII does take a fair bit of steel off when set to micro bevel.

I too hollow grind on my Record WG250 - a Tormek rip off basically, but really good machine. I may try Derek's idea as I sounds obvious and you can see from his photos that it works (thanks Derek).

Jonny

 

[Derek Cohen (Perth Oz)]

I have a question regards your technique, do you create the edge by simply placing thehollowed bevel on the sharpening plate/stone and use the top and bottom of the bevel as the 'guide' to create the edge or do you lift the bevel slightly so only the leading edge contacts the stone?

Hi David

Depending on the width of the blade, I will either move the blade sideways, or pull it back towards myself, sometimes both.

What is common to both is that the hollow is placed flat on the medium, so that both sides of the hollow are touching the medium. You can tell when it is flat when the chisel can be held to the medium by a finger pressing down behind the bevel.

Narrow chisels are not stable, and so place the flat down and pull the bevel back straight back towards yourself.

Wide blades may be done the same way, alternatively move them in a side-to-side motion. This is particularly stable with wider blades.

This is side sharpening ...

I avoid back-and-forth movements as they encourage rocking.

Regards from Perth

Derek

 

[Bluekingfisher]

Much appreciated Derek, noted & fully understood you addressed the issue regards narrow blades too. I'll try out the theory this evening if I get home from work early enough.

Good luck with yours too Jonny.

David

 

[Paddy Roxburgh]

I sharpen most of my tools freehand with a single bevel. I aim for flat but probably they are slightly rounded ala Jacob and Paul Sellers. People often say that a micro bevel is quicker but I don't find it takes long to sharpen with a single bevel. I used to use a honing guide and a secondary bevel and still do for the high angle iron in my block plane and the 35 degree bevel on my mortice chisels, to be honest I find that it is slower than freehand and that's not counting the time spent looking for the guide and setting it.
Paddy

 

[David C]

Now I am planning to put some clips on you tube to show how slow honing guides are !

Looking for guide 5 seconds.

Setting guide maybe 10 to 15 seconds.

David Charlesworth

 

[Corneel]

Please add the video where you sharpen a gouge in the jig too.

 

[David C]

Don't use gouges much. Generally in cannel.

Many people make fancy ones for woodturning gouges though, like Tormek.

David

 

[bugbear]

Please add the video where you sharpen a gouge in the jig too.

If I'm planing a flat board I use a big, flat soled plane.

If I were making a long moulding, I'd use a moulding plane.

If I'm working a curved edge I use a spokeshave.

If I were making a violin scroll I'd carve it.

But it would be dumb to carve a large flat surface, but I have the skills and tools to do it.

Today's phrase is "task appropriate technique"

BugBear

 

[Corneel]

We had the same discussion some time ago when I came up with a long list of tools that didn't fit a jig. Gouges and moulding plane irons of course. But also the drawknife, the axe and broadaxe, mortise chisel, deey cambered scrubplane iron, knife, spokeshave, routerplane etc. In the meantime there have been some tremendous developments in the field of sharpening jigs. We have the drawsharp at something like 80 euro. LV came with the narrow chisel jaws for their MK2. LN of course with the new jig, forgot the price, plus separate jaws at an additional price. IF I remember correctly they even have mortise chisel jaws that are too small for pig stickers ( but oh well, just throw them oldfashioned things in the bin). When you want to sharpen your LN mortise chisel you unscrew the standard jaws and replace them with the mortise ones, recalculate the projection ratio and of you go. After first flattening your stones of course. And oiling the small wheel. Oh, and now we need a Tormek too. With all the jigs of course.

In the meantime nothing happened on the freehand front. It's still the same old routine. When the chisel is dull, turn around to the stones, plop the edge ontk them and move it back and forth. Strop a bit and return to work. Couldn't they think up something more exiting?

 

[Beau]

A coarse abrasive removes material quickly but doesn't leave a good edge.
A fine abrasive leaves a good edge but removes material slowly.
Using a small secondary bevel is the best of both worlds. Because it is a small area, the secondary bevel can be honed quickly with a fine abrasive. Trying to hone the entire bevel with the fine abrasive would take far longer* (and is also a bit of a waste, as the the finish on the area behind the bevel is irrelevant).

I can't see much advantage to using a single bevel, unless it is Jacob's rounded bevel where only the tip needs to be honed. But then, that's just the same theory as a secondary bevel, just without a clear boundary between the two bevels.

* of course, if the entire bevel is only a small bevel anyway, say on a 1/4" chisel, then you don't waste any time by honing the entire bevel.

This =D>