Front-and-back or side-to-side? *LINK*

Re: Front-and-back or side-to-side?

Pam Niedermayer - Austin, TX

>Yeah, figure 8 to use most of the stone, saves flattening effort. Aside from that, by the time Harrelson gets his blade in the skate and adjusted, I'd be done freehanding it. Makes sense for large jobs, like grinding out a nick.

Pam

Front-and-back NOT side-to-side because..

Ian (in Sydney, Australia)

>you sharpen a knife side-to-side to intentionally leave a series of tiny "teeth" along the cutting edge.

also when you go side to side the abrasive should round the edge over somewhat and you run the risk of pulling out a marstenite(?) grain leaving a hole.

you strop a razor back-to-front to avoid leaving "teeth" so you get a smooth shave

Paul Williams deliberately orientates his blades so that the steel grains are at right angles to the cutting edge. Side-to-side sharpening would polish across these grains rather than along the grain.

I'm not sure how other blades are orientated in respect to the crystaline structure of the steel.

Re: edge morphology

Adam Cherubini, NJ

>Wouldn't you be better off with longitudinal scratches? The blade should be stronger this way. Pretty sure that's where Leonard Lee is coming from.

My take is that Harrelson spent a lot of time and effort working to a set of somewhat arbitrary requirements. I would prefer to see guys challenging the status quo and suggesting new (or old) better ways of sharpening. The more I sharpen and the more I work, the less convinced I am that we have the right answer regarding flat backs and planar bevels.

Adam

I sharpen edge to edge

Andrew F in Australia

>Hi Ian,

I sharpen edge to edge often, other times, in figure 8

I find the edge to edge gives a straighter blade. (using 2000# on a MDF scrap so I don't have to worry about damaging a stone)

On a stone, I sharpen in figure 8's

I can recall that Japanese blades were sharpened edge-to-edge, but I can't remember where I heard this.

On a separate note, going back to my first trade and the comment on plane blade metallurgy, the carbides that are in the blades would be aligned in rods going end-to-end along the plane blade to a certain extent (affected by heat treatment)

However, as the steel is heat treated, the grains are equiaxed and have no preferential direction.

With good heat treatment, the carbides would be somewhat dissolved and re-distributed uniformly as well.

Cheers,

Andrew

IIRC, part of the reason...

Ted Owen, Pittsburgh

>Harrelson uses side-to-side is better burr removal. He feels that working the burr back and forth causes it to break off, leaving a courser edge. Removing it side-to-side flattens the burr in a more gentle manner, leaving a finer edge and enabling quicker honing.

Many carvers, including Joel, hone their chisels side-to-side. Some hone both inside and outside surfaces that way, with the possible benefit of gentle burr removal.

Best, Ted

Exactly in-between

Denis Ch�nard, Orl�ans, Ont.

>I hone my blades by holding them at a 45 degree angle to the stone. It provides for more stability when freehanding.

That's how I was taught at Rosewood, and I haven't found a better method yet. Makes it easy to do cambered blades too.

DC

Michael Dunbar

Patrick Gibbons

>Dunbar used to advocate side-to-side because it allows the novice to keep the bevel angle more consistent. There's more metal in line and less rocking motion. But this is to facilitate freehand sharpening. Using a figure 8 motion was advocated in many older sources I've read but these sources were using oil stones that did not dish as is the problem with water stones. The rationale was that most of these stones, particularly Arkansas stones, were not as wide as the plane blades being sharpened. Good stones were expensive. Holding the blade askew or moving in a figure 8 would facilitate sharpening a blade wider than the stone being used. Neither of these scenarios are concerned with getting a better edge because of some superior dynamic involved with side-to-side motion.

Corner to corner

Stephen Shepherd in the State of Deseret

>My 32 inch Ohio limestone hand cranked grindstone wheel leaves scratches from front to back.

I then sharpen over a soft abrasive, Washita or the local sandstone. I then hone on a fine, Arkansas or English Slate in a motion over the entire surface of the stone. It may be a figure 8 or a 4 and one half or an X, but it goes over the entire stone. As I was told when I was an apprentice, all of the teeth on the saw are sharp, feel free to use them and the entire surface of the stone is abrasive, not just the middle.

I will break off the burrs by running the blade sideways through a piece of wood to speed things up. My basic motion when doing the fine honing is from side to side as less movement is necessary to accomplish the mirror finish.

I also do not use oil when sharpening, too messy, I do use oil to clean the stone however.

I finish off on a leather strop with tripoli or rouge.

The more time sprent sharpening the less time spent using sharp tools.

Stephen

Re: Corner to corner

Marv

>I have a favorite spot on the concrete floor of my shop. Actually I have two spots, one where I use oil and the other I use water. I'm finding it harder and harder to get back up off my knees these days so I might have to resort to store bought stones soon, maybe some of those Arkansas kind. I figure if I can't see the edge shining back at me, it's sharp enough.

Marv

Re: Front-and-back or side-to-side? *LINK*

Brent

>This is the first jig I have seen that works side to side. Freehand side to side will produce very different results. As such, it is definitely a contribution to sharpening with jigs - which I am in favour of.

With no experience with this jig the following is only a guess at how it will compare to other methods.

Setting - from the video, it appears to be a little haphazard. People who tried to use the LeeValley angle setting jig with the earlier version of their honing jig will know that this method of angle setting is a bit of a crap shoot. I think he should work a little more on angle setting.

Honing - the video shows these shiny bevels with just a little fiddling around. Smacks of Uri Geller to me. However, when honing with my jig I push the blade back and forth about 3" about 30 times per grit. Say about 180" of abrasive under the edge. If he slides the whole thing back and forth 6 inches (on an 8" stone) 15 times, he would also have 180" of abrasive under the edge. Should get about the same result. (In the video he uses fussy little rubs. I would favour full length motions, not short choppy motions.)

Microbevels - not clear how to do it with this jig. You could slide a piece of very thin plastic under the wheels to get the desired effect. Since the extension is so small (less than 1") you would probably have to use plastic about 0.01" thick. Plastic this thin would probably deform quickly with use. It may be possible and would improve his system.

Scratching - are scratches along the edge better or worse than scratches across the edge. To put the problem in perspective, the last abrasive will put a scratch (assuming 0.5 micron final abrasive) about 0.25 microns deep -- 0.00001" deep. During use, and the blade cuts just fine the whole time, rubbing the blade against the wood removes metal at the edge, shortening the blade by about 0.0002". So, blade wear is 20 times the depth of the deepest scratch left by the last abrasive.

Of course, if you don't use microbevels, then the deepest scratch is probably that left by the coarsest abrasive you used, less any metal you honed off after that. If the coarsest abrasive you use at the edge is 15 micron (600 grit), then the deepest scratch is about 0.0003" deep. Honing with very fine abrasives, if you don't use microbevels, does almost nothing. You can see that the amount of metal you hone off during use and the depth of the deepest scratch left by 15 micron paper are about the same.

With side to side honing on coarse abrasives, you can imagine a scratch almost parallel to the edge that cuts deep into the metal. This scratch would not be removed by later honing unless you used microbevels. You might imagine this wedge of metal being ripped off during use on hardwoods. A similar scratch perpendicular to the edge would not weaken the edge since it would not create a thin sliver of metal.

If someone felt compelled to send me one of these, I would so some testing and return it, putting the results up on my sharpening pages - see link. The web pages contain discussion of the numbers mentioned here.


http://www3.telus.net/BrentBeach/Sharpen/

Duh *LINK*

Brent

>I was thinking about why the side sliding jig is so small - both it and the tool edge have to fit in the width of a bench stone. So, why not hold the stone in a vise - like mine - but sideways, not endways. You could run the jig on the vise, not the stone and use any sized jig.

Duh

You could use my jig since it slides on glass.

You could configure 3M abrasive on glass with a 3" wide, 11" long piece of abrasive on a piece of glass 8" wide by 11" long, giving you a 5" side portion and use my jig. You could use wooden slips for microbevels. You could do back bevels.

So, I don't need to borrow a jig to try this out.

I will give it a try and write up a web page. The link below is to the stone vise design for using the stone lengthwise.


Bench stone holder

Re: Front-and-back or side-to-side?

Warren in Lancaster, PA

>Brent, you write "Honing with very fine abrasives, if you don't use microbevels, does almost nothing." Are you talking about paper abrasives only or stones as well? Using stones on a flat bevel, if we are having trouble removing scratches from the previous stone, an intermediate stone is the solution. It runs counter to experience and logic to suggest that using a finer stone will not improve the edge.

Re: Front-and-back or side-to-side?

Brent

>My comment was based on my experience using fine abrasives like 5 micron and 0.5 micron. When I start to hone a microbevel with 5 micron abrasive, I increase the honing angle a bit, so the tool is resting on the edge (just the edge, no other part of the previous bevel). Honing quickly produces a narrow microbevel because the abrasive is touching the tool in a very narrow area.

Because the angle is slightly higher, the depth of metal removed is comparable to the depth of the scratches left by the 15 micron abrasive. If I tried to hone the entire previous microbevel, it would take far longer to get the same depth. You could do it, but you would run out of time and abrasive.

The same hold true for the 0.5 micron abrasive. Because the tool is at a higher angle, it begins resting on the edge alone. Honing quickly produces a new microbevel that have removed enough metal to get beneath the scratches left by the 5 micron abrasive. Again, I could not get the same effect honing at the 5 micron angle.

In both cases the total amount of metal removed is small, but the depth is ok because the metal removed is all at the edge.

The fine abrasive is effective because the area of contact is small so the force per unit area is high. With a large area of contact - the entire previous bevel - the abrasive is less effective.

I honed many irons and kept getting microbevels about the same width. It was a long time before it occurred to me that it was not a skill of mine but a natural limitation of the abrasive. Once the microbevel gets wide the rate of removal slows down, so the rate of widening slows down.

If you hollow grind on a wheel, then hone with say 15 micron abrasive resting the blade on the lips of the hollow, you create a wide bevel at the edge. Any further honing with finer abrasives with the blade resting on both lips will be working too wide a surface for the finer abrasive to improve the edge much. There aren't really any grits between these two to try to remove more metal.

figure 8

dave brown

>I wouldn't do a figure 8 because it presents too many possibilities for rocking the blade up on a corner or mess up your bevel angle. It's hard enough to keep the bevel consistent when freehanding but figure 8's make it harder still.

I wouldn't agonize a lot over which sharpening method puts the best striations in the proper orientation when viewed under a scanning electron microscope. Pick a method that's quick to execute, easily repeatable and feels comfortable to you.

Re: figure 8

Joel

>I would agree - a back and forth across the stone will use the entire surface including the corners and is far more stable than round the figure 8 (escpecially on narrow edges))

Re: figure 8

David Charlesworth

>Agreed. I can see no benefit from figure 8.

In fact it is clear that at the crossing point the stone gets double the wear.

David Charlesworth

Re: Front-and-back or side-to-side?

Warren in Lancaster, PA

>Thank you Brett. I have no experience with sharpening on sand paper or loose grit.

I spend 15 or 20 seconds for final honing a full bevel on an Arkansas stone. After 30 years and more than a hundred thousand sharpenings, the wear on the hard stone is so little that I haven't yet flattened it. I don't expect to run out of time or abrasive.

Re: Duh !! Broken link fixed *LINK*

Brent

>Sorry about the bad link in the original.

As well, I have started to write up a discussion of side sharpening which will include some micrographs of edges side sharpened and perhaps an edge wear test later. That page is at

Side Sharpening

and, yes, I did check both links this time.


Updated benchstone holder link