A Sharpening Thread Observation

[ken hatch]

I must have too much time to sit around and stare at my toes or something but here goes anyway. Do most of you folks in your day to day sharpening, after finishing with whatever stone, strop, or skin you use for the finial touch, test the iron for sharp with whatever test you prefer for testing sharpness? Be it shaving body hair, paring end grain of white pine imported from Finland, or dropping a long hair from a 13 year old strawberry blonde on the iron to see if it will split.

The reason I ask, it seems most replies to "how to" sharpening threads will advise as a final step "testing" the iron for sharpness. Maybe I'm different, could be I don't know what I'm doing, or even both but I almost never "test" a iron. When I finish sharpening I look at the iron closely, feel the edge and if it looks sharp and feels sharp it is sharp and I either rack it if it is a chisel or put it back in the plane if it is a plane iron.

If there is a better way enlighten me.

ken

[bridger berdel]

Sounds like you use the eyeball test.

Sometimes I'll test to see if it shaves arm hairs. Sometimes the fingernail catch test, or the thumbpad test. And yes, often the eyeball test.

[ken hatch]

Sounds like you use the eyeball test.

Sometimes I'll test to see if it shaves arm hairs. Sometimes the fingernail catch test, or the thumbpad test. And yes, often the eyeball test.

Bridger,

I have a junk 9 1/2 and a off brand Stanley that need a home. I'm out of shelf space to store 'em. Trade you for something.

ken

[Andrew Hughes]

My test is see how the edge grabs the skin in the palm of my hand below my thumb.Just a lite touch with the edge will feel like it's sticking to my skin.A edge that need more work will barely grab.Its really scientific stuff and hard to explain.🐌

[Jim Ritter]

I mostly use the eyeball test if I can't see any light reflected anywhere, it is sharp.
jim

[Jim Koepke]

It really depends on what is going on. I seldom sharpen a tool just before putting it away, but it does happen on occasion. Most of my sharpening takes place during the time a tool is being used. My stones are always ready or a few moments from being ready to use.

It often comes to mind that something I do may be considered bad practice and isn't advisable for others to do. Since handling my first knife I have carefully touched a sharpened edge to test it. I haven't cut myself yet doing this. I can tell by the way it feels if an edge is sharp and usually how sharp. Most of the time just for the heck of it I will see how it cuts arm hair.

What it all actually boils down to is knowing how a sharp edge performs on a known surface. If a chisel isn't paring well or a plane can't take a light shaving, it is likely time to hit the stones.

The "white pine from Finland" test has slipped by me. If one is pairing dovetails the ability to slice fine shavings from end grain is an important feature.

We have also heard about being able to shave arm hair after sharpening an edge with 80 grit abrasive sheets. Not sure I would want to watch that one. Like a sharp razor a sharp edge on a blade will shave the hair without snagging or pulling. It will not leave any behind. An almost sharp blade will remove some hair, but not all in its path.

On softwood end grain, like pine, a sharp chisel can take a very fine and most importantly a fully controlled shaving. It can slice the fibers without causing separation looking like big gaps.

jtk

[Robert Engel]

I use the forearm shave test but once I get in the groove I don't test at all.

Some times I do the soft endgrain.

Andrew - Really? I wouldn't recommend that technique to anyone!

[Max Neu]

A lot of times I see how well it slices through paper,if it's sharp it will cut through it effortlessly without any pushing or pulling of the blade,just straight down.

[Brian Ashton]

I must have too much time [snip]
ken

All depends on where I am. If I'm on site I only have a diamond stone so I gently hone till the wire edge disappears and maybe give it a bit of a nail test. If I'm in my shop I have a system that will leave a fantastic edge and I use the nail catching and skating test extensively. The edge on site I obtain from a diamond stone is functional (I don't even try to palm it) the edge I can obtain in the shop is surgically sharp. And everything in between.

[Malcolm Schweizer]

My test is to go back to my project and continue doing whatever it is I was doing that dulled it.

[Prashun Patel]

I touch the blade with my finger and look at the mirror polish - but honestly just to marvel at a freshly prepared edge.

I gotta believe that most people have realized that if you follow the same regimen on the same blade, the results are predictable without having to test it with a hair or your arm.

[Brian Holcombe]

For a batch of new tools I will test them, but generally speaking I will not. Their reaction to the work is more important than if it will shave my arm hair.

If you are testing them because you want to see how they're doing in the work, look closely at the shaving, it will tell you have refined your edge is.

[Steve Voigt]

My test is to go back to my project and continue doing whatever it is I was doing that dulled it.

Exactly. Me too.

[bridger berdel]

Bridger,

I have a junk 9 1/2 and a off brand Stanley that need a home. I'm out of shelf space to store 'em. Trade you for something.

ken

Ken, you're an enabler. An evil man.

What do you need in trade?

[Mark AJ Allen]

I test all 'flat iron' tools; plane irons, chisels. The first indicator is to ee how small an angle I can make between the back bevel side of the blade and my fingernail until it stops catching. The smaller, the better. I will pare some pine or cedar as well; always have some of that laying around. Some day I might get enough confidence in my sharpening skill to stop checking but there is something satisfying about getting that small angle or a lighter than air shaving from endgrain softwood.

[Jim Koepke]

...
Some day I might get enough confidence in my sharpening skill to stop checking but there is something satisfying about getting that small angle or a lighter than air shaving from endgrain softwood.

Nah! The test score is almost always satisfying. Even with confidence, when there is no more hair on my left arm blades get tested on the right.

jtk

[Archie England]

I like paring SYP end grain as final test because it definitively shows whether the burr has been removed. I use the thumbnail grabbing test while sharpening. I suppose I do this out of a lack of confidence.

[Sean Hughto]

The only reason I sharpen is to keep my forearms shaved.

[Dave Cullen]

My test is to go back to my project and continue doing whatever it is I was doing that dulled it.
Ditto. Though I will check to be sure the wire edge is gone before taking the time to remount a plane iron.

[Jeffrey Martel]

The only reason I sharpen is to keep my forearms shaved.

I've always wondered if at a woodworking show/convention what ratio of the attendees would have one or both forearms missing hair.

[ken hatch]

Ken, you're an enabler. An evil man.

What do you need in trade?

Bridger,

I really do not need anything and have no room to store it if I did. Maybe something small and "shop" made such as another one of your birdcage awls?

ken

[Brett Luna]

The discussion here reminds me of of a couple of wet shaving and straight razor forums I've frequented. I've never put much stock in the hanging hair test and the only thing I shave hair with is the aforementioned razor. For tool blades, I tend to run my finger over the edge (not along or against it) and visually inspect it to see that light strikes it uniformly. I might try it on a scrap of paper or wood but mostly, I just go back to using the darn thing.

[paul cottingham]

Thumbnail catch test. Works fine.

[Malcolm Schweizer]

My test is to go back to my project and continue doing whatever it is I was doing that dulled it.

This was a quick response via iPhone. Not intended to sound as sarcastic as it sounds when I go back and read it. If I were testing a new stone or sharpening a tool for the first time, I usually do a "rub your thumb over the blade (not side to side!!!!) test, or maybe the hair test, although that test leaves me with a hairless patch for a few days. Depending on the tool, I would usually load the blade or take the tool and do a test cut in the manner it was made to be used for- pare some end grain with a chisel, plane some flamed maple with a smoother, shave something with a spokeshave, etc, etc, etc...

[Robert Hazelwood]

I've always had the habit of touching the edge with the fingertips of my left hand. I gently touch the edge and kind of slide the fingertips off across the edge. If you do this periodically as you sharpen, and every time you sharpen something, you will develop a pretty good feel. For example, once I finish up on the super fine stone I can usually tell when I didn't spend quite enough time on the medium stone because it doesn't have the right kind of bite on my fingertips. This is not any kind of objective measure but the more you do it the more value it has. It's usually my sole method.

I find that shaving and paper cutting can be difficult to gauge. My arm hairs are very difficult to shave, apparently. When I was first starting to sharpen I'd have edges that struggled to shave my arm hair but could pop them clean off another person's arm. Cutting paper is a good test for knives but I find it very awkward to do with chisels and plane irons.

The best practical test seems to be paring end grain of a soft but brittle wood like pine. If it can do that well (leaving a polished surface with no marks) then it's going to be able to do virtually anything else you'd need to do.

A last thought is to use an oiled leather strop. This is something I've read about from David Weaver, I think. A smooth leather strop with no compound, just oiled, will reveal any flaws in an edge when you pull it across. Burr fragments or chips will show up as lines on the strop. Usually when a freshly sharpened edge is less than ideal it's because there is a remnant of burr. The strop will tell you if you need to work the edge a little more.

[bridger berdel]

I've always wondered if at a woodworking show/convention what ratio of the attendees would have one or both forearms missing hair.

Galoot pattern baldness....