Thoughts on Sharp

[Jim Koepke]

My intention was to not hijack Ken's thread on New Chisel Prep. This thread is to share thoughts on sharpening, sharpness and even testing sharpness.

Often the first sign of a blade needing attention is the quality of work a blade is performing. On a plane, the shavings can tell a lot. Here is a plane with a small nick in the blade:

424230

The spot with the nick is not cutting creating a split in the shaving. Even though a thicker shaving may not split, it will leave a little line on the work that can be felt.

A thin shaving requires a sharp blade. Some of my blades do not seem to nick up like an A1/2 blade. They continue to take smooth shavings they just can not be dialed in to be super thin shavings.

The actual nick is difficult to photograph:

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You may be able to see where it is, follow the arrow. A dull spot or a nick will often show up under close examination under light. Even with poor eyesight a sparkly or a dark area can be seen.

After sharpening this blade it took a good full width shaving without splits:

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The wood is a piece of alder from the firewood pile.

Testing on end grain is a helpful test for many folks. Here is an After & Before of a 1-1/4" Sandvik chisel:

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The patch to the right of the red line shows the surface made by a dull chisel with a few nicks. It is still sharp enough to pare a joint that will be hidden when assembled. To the left of the line is a patch cut with the same chisel after a trip to the oilstones. The shaving on the left patch was thin enough that it didn't remove remnants of the streaks from before the chisel was sharpened.

Here it is in action:

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Smooth cutting of end grain may not be important to many woodworkers. If one is carving details such as letters or other 3D work, it can be the difference between looking sharp or looking rough.

Some folks do not like end grain to show. My taste differs:

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My DVD/CD/Blue Ray drive just didn't look right without a little elevation. This is also a piece of alder firewood, smoothed with an LN #62.

jtk

[ken hatch]

Jim,

Good photos and a good demo.

ken

[Doug Dawson]

My first question would be, what is the chisel _for_? I have some awesome antique chisels that I have for many years used for mortising, and they have rust pitting that you would never get rid of, and they work just fine. Actually, some other such afflicted chisels work similarly well for paring. Sorry to conflate the issue, but that's just what I do.

[Jim Koepke]

Sorry to conflate the issue, but that's just what I do.

Sacrilege! Blasphemy! Treachery! :eek::eek::eek::D:eek::D

Your comments are valid in that a chisel or blade only needs to be as sharp as the job at hand requires. After all, sharpening is really a process. Go to the stones or strop to get an edge and back to work. Though it is often treated as a ritual. Sometimes it is the ritual that teaches us the process.

In a plane, a pitted blade can be used like a toothed blade if it is pitted enough. The original blade in my #5-1/2 was very pitted. It also had a bit of camber. Recently it occurred to me, when it came to my shop, it was set up to be used as a scrub plane. This was a few years before my first use of a scrub plane. Recently it was set up with the original blade and is now my fourth plane set up as a scrub. It will likely go back to a straight blade since it is the only #5-1/2 in the shop.

jtk

[mike stenson]

Your comments are valid in that a chisel or blade only needs to be as sharp as the job at hand requires. After all, sharpening is really a process. Go to the stones or strop to get an edge and back to work. Though it is often treated as a ritual. Sometimes it is the ritual that teaches us the process.


Sometimes, I feel that in these conversations "sharp" is the end-goal, rather than simply a means to an end. You're correct, it only needs to be sharp enough to do the work at hand. Often that means I'll stop sharpening before it's reached "sharp for sharps sake" and just get back to work. If I'm paring down the interior surface of a mortise, or a tenon cheek I in no way need to be as sharp as a final exterior surface.

[lowell holmes]

Sharpening is good and so is woodworking. Two different activities, but equally fun.:)

[Jim Koepke]

Sharpening is good and so is woodworking. Two different activities, but equally fun.:)

They may be "different activities," but they are deeply connected.

Not much quality woodworking will occur without being able to sharpen your tools.

jtk

[steven c newman]

And.....not much woodworking will get done, if'n all you are doing is sharpening....and sharpening...and sharpening....:D

[Frederick Skelly]

And.....not much woodworking will get done, if'n all you are doing is sharpening....and sharpening...and sharpening....:D

While it's not my personal "gig", there are people who make a sub-hobby out of sharpening. IIRC, there was a japanese-style sharpening contest last year in NYC - I remember seeing a video posted. I think our own Brian Holcombe participated as did Wilbur Pan (Giant Cypress blog).

It's all good. Some people like to challenge themselves to develop sharpening skills, others to cut perfect dovetails, others to make beautiful tools, etc. There's plenty of room in this hobby. Do what pleases you.

Fred

[Jim Koepke]

And.....not much woodworking will get done, if'n all you are doing is sharpening....and sharpening...and sharpening....:D

With the blade in my original post, it took more time to put water in the tray and soak my stones than it took to go through the grits on three stones.

Not much woodworking will get done if one doesn't take care of sharpening their tools.

To paraphrase what Fred said, people find their pleasures in various endeavors.

Some find displeasure in the basic necessary endeavors in life.

jtk

[Andrew Pitonyak]

424232

You may be able to see where it is, follow the arrow. A dull spot or a nick will often show up under close examination under light. Even with poor eyesight a sparkly or a dark area can be seen.



Want to photograph that nick? Get one of these for $23

https://www.amazon.com/gp/product/B07DRGR6LX

I just ordered the stand for $21, will see how that works. The included stand is not so nice. It works, but is not so nice.

[Jim Koepke]

Want to photograph that nick? Get one of these for $23

https://www.amazon.com/gp/product/B07DRGR6LX

I just ordered the stand for $21, will see how that works. The included stand is not so nice. It works, but is not so nice.

That would be a lot of fun, but my only way to use it would be to connect it to my computer. That would mean running into the house all the time to take a picture and then running back to the shop.

To bad it doesn't have a built in power source and a memory card.

jtk

[lowell holmes]

I use diamond hones to sharpen my tools.

[Andrew Pitonyak]

That would be a lot of fun, but my only way to use it would be to connect it to my computer. That would mean running into the house all the time to take a picture and then running back to the shop.

To bad it doesn't have a built in power source and a memory card.

jtk

Luckily, this one comes with everything you need to connect it to a an Android phone. The cable can connect to standard USB, as well as C and some other one, mini I think. In other words, it will work newer and older android phones. I do not know if it will work for iPhones, I think so. It connects as though it is a web cam. I also did NOT want to have to run back and forth. Spend a bit more money and they have one with a built-in screen, but $23 made it worth it to give it a try.

[Jim Koepke]

Luckily, this one comes with everything you need to connect it to a an Android phone. The cable can connect to standard USB, as well as C and some other one, mini I think. In other words, it will work newer and older android phones. I do not know if it will work for iPhones, I think so. It connects as though it is a web cam. I also did NOT want to have to run back and forth. Spend a bit more money and they have one with a built-in screen, but $23 made it worth it to give it a try.

The price is great. Since moving to an area without cell service, my cell phones were given up almost a decade ago.

jtk

[Andrew Pitonyak]

The price is great. Since moving to an area without cell service, my cell phones were given up almost a decade ago.

jtk

My next task is to connect it to my daughter's Android tablet. No phone there. But that presumes that you have a tablet.

[Jim Koepke]

My next task is to connect it to my daughter's Android tablet. No phone there. But that presumes that you have a tablet.

Candy has an iPad. The only time she let me touch it was when the old one died. Then she wanted me to fix it. It took a couple of days, an ice pack, a new iPad and a bit of a struggle to get her old stuff onto her new iPad.

jtk

[Marinus Loewensteijn]

Toughts on sharp: At times the edge can be too sharp. It all depends on the angle of the edge versus the direction of cutting. Are you slicing, are you sawing or is the edge perpendicular to the direction of the movement. E.G. end grain will certainly be better cut when using a skewed blade. I also do not want to cut fresh bread with a knife that is like a razor blade.

[Jim Koepke]

Toughts on sharp: At times the edge can be too sharp. It all depends on the angle of the edge versus the direction of cutting. Are you slicing, are you sawing or is the edge perpendicular to the direction of the movement. E.G. end grain will certainly be better cut when using a skewed blade. I also do not want to cut fresh bread with a knife that is like a razor blade.

Marinus,

Often bread knives will have a serrated edge so the bread can be sawn. Like a dull saw, a dull bread knife can make the work difficult.

There have been more problems for me trying to cut bread with a dull knife than one sharp "like a razor."

For buttering said piece of bread, a non-sharp knife is preferred.

jtk

[Marinus Loewensteijn]

Marinus,

Often bread knives will have a serrated edge so the bread can be sawn. Like a dull saw, a dull bread knife can make the work difficult.

There have been more problems for me trying to cut bread with a dull knife than one sharp "like a razor."

For buttering said piece of bread, a non-sharp knife is preferred.

jtk

Similarly to the bread knife, a saw would not be much good it it had a straight edge, it needs to be serrated.

In a number of knife forums there is a definite aversion to making a knife edge too much of a razor finish, it is better to have a "microscopically serrated edge" for lack of a better description. This is normally achieved by grinding only to a coarser grit and no stropping. A knife sharpened as such appears to perform better and appears to "stay sharp" longer in slaughtering an animal.

[Jim Koepke]

Similarly to the bread knife, a saw would not be much good it it had a straight edge, it needs to be serrated.

In a number of knife forums there is a definite aversion to making a knife edge too much of a razor finish, it is better to have a "microscopically serrated edge" for lack of a better description. This is normally achieved by grinding only to a coarser grit and no stropping. A knife sharpened as such appears to perform better and appears to "stay sharp" longer in slaughtering an animal.

Yet if you look at a saw blade a rip saw is sharpened to have offset rows of tiny chisels. A crosscut saw has rows of tiny knives. The "straight edges" are just tiny and oriented at an angle to the line of the saw plate.

Delving into the area of edges honed for a specific purpose a hunter needs a different edge than a barber. The edge a barber uses would dull rapidly if used to dress a deer. A barber wouldn't likely have many repeat customers if he shaved clients with an edge akin to a hunters knife.

My edges are pretty much honed for three specific purposes, woodworking, gardening and use in the kitchen.

For my kitchen knives the 'test' is being able to cut a ripe tomato without making a mess of it.

My straight knife seems to work fine when a loaf of bread needs cutting.

jtk