Scissors sharpening! Many questions!

[ian]

Let’s start another scissors thread. Here are a couple questions:

1) How does the grit you use affect the cutting action? I’ve been testing on plastic kitchen trash bags, which I think are slightly easier to cut than silk, if the reference I saw was accurate. Should they still be able to cut ok at a low grit? I guess what I’m wondering is whether (given all other variable equal) the difference is mostly the smoothness of the action and the perfection of the cut. Like when I do a sharpening progression that’s aggressive enough to get out some nicks, should I be able to test the quality of the edge on a Chosera 400, or do I have to give it a high grit polish before it becomes apparent how well they’ll work?

2) Say I’m sharpening these scissors here.

I have a good edge over most of the blade, but I’m not getting contact within 8mm or so from the pivot. I wonder if this is just a byproduct of sharpening without touching the inside of the scissors. I mean, the insides are concave ground, so if you sharpen the edges will move away from each other as they move into the concavities. There’s enough curvature to the edges so that they still make contact farther up the blade, but near the hinge there’s not enough distance for the bend to take effect. Is there a way to fix this?

3) On the other end of the spectrum, I have a couple pairs where the tip won’t cut trash bags, even when the blade is sharp. On these, the inside hasn’t been touched. Is this a set problem that I wouldn’t be able to fix without adjusting the bend?

 

[Runner_up]

I don't have the answer but I'm certainly interested.

 

[ian]

All these frenetic questions may or may not have something to do with the fact that I’m sharpening scissors for people and realizing that unlike with knives, I can very easily screw something up in a way that I won’t be able to fix....

 

[Carl Kotte]

I did my first pair of scissors the other day, much inspired by thee. Not bad for a first attempt, but I set my expections to 0.

 

[Rangen]

I was just sharpening some weird curved blade scissors with a tapering diamond rod, a few hours ago. They came out well.

Which is not to say that I am the Master of Scissors. Quite the contrary. Their oddball bevel angles defeat my intuition, so I usually resort to a guided sharpener. Of course I could not do that with the curved blade ones.

What I can say is that I am extremely gentle with the bevel, and do nothing on the opposite side except very careful deburring, mostly at right angles to the edge. I do not know what to do with a scissors blade with a serious nick. I'm not even sure one can fully fix that without screwing up the mysterious (to me) geometry of the scissors.

 

[Rangen]

Also: I have gone finer than 400 grit on scissors only with some very nice Japanese tailor scissors. Doesn't seem necessary for the rest.

 

[ian]

Also: I have gone finer than 400 grit on scissors only with some very nice Japanese tailor scissors. Doesn't seem necessary for the rest.

Yea, I’ll have to test out what a 400 vs 16k edge really feels like and see if there’s much of a difference.

 

[coffeelover191919]

The Tojiro shears (The $52 one from amazon, CKTG, et. al. ) have a concave / convex shape. How is this done on something like a shapton 1k / 2k / strop? Is it possible to simply strop each scissor blade for maintenance each week to prolong its edge-life?

 

[TB_London]

Scissors are a dark art, getting them cutting heel to tip needs the right amount of curvature and tension.

 

[ian]

F**k scissors.

 

[ModRQC]

I just trash mine and buy new ones... of course I don't use high end scissors. Good luck with that. Must be the most boring thing to have to work on...

 

[ian]

Must be the most boring thing to have to work on...

Opposite of boring. Maddening, delicate and frustrating, since they're so easy to permanently ruin.

 

[Kgp]

I know it's heresy, but I picked up a Chef's Choice scissor sharpener off ebay for next to nothing that does a great job on my wife's good sewing scissors.

 

[ModRQC]

Your vision. I find the instrument boring. Wouldn't bring myself to sharpen one. Fun in sharpening knives is that they're knives and I love knives. Passion makes perfect.

Don't give a f**k makes...

F**k scissors.

 

[The Edge]

I won't touch hair shears, but I sharpen kitchen and other generic shears quite a lot. I won't say I'm great at it, but I start off on a super low grit to take out nicks and dings. I just freehand the edge by first looking at how it sits on the stone at a couple different points. Once I feel I know where the angle is across the length of them, I start sharpening until I can feel a burr. I then treat them like single bevel knives, and deburr on the flat or concave side. This is easier on the knives that can come apart, as then I'm more confident that I'm keeping everything as it's supposed to be. Though I do find that there is a slight bend on most scissors 1/3 of the way to the tip (I'm guessing it's there to keep the tips in contact with each other, and not let whatever you're cutting get caught between the blades).

I try not to even close the scissors until I get to at least 3k in grit, as it always feels harsh in the action. I'm guessing that lower grit edges won't last nearly as long with scissors, as the edges are rubbing against one another. I'm sure you could take a lot more time on a coarser stone, and get it to work quite well, but it's easier for me to step up to a finer grit once I've flipped the burr.

 

[ian]

I won't touch hair shears, but I sharpen kitchen and other generic shears quite a lot. I won't say I'm great at it, but I start off on a super low grit to take out nicks and dings. I just freehand the edge by first looking at how it sits on the stone at a couple different points. Once I feel I know where the angle is across the length of them, I start sharpening until I can feel a burr. I then treat them like single bevel knives, and deburr on the flat or concave side. This is easier on the knives that can come apart, as then I'm more confident that I'm keeping everything as it's supposed to be. Though I do find that there is a slight bend on most scissors 1/3 of the way to the tip (I'm guessing it's there to keep the tips in contact with each other, and not let whatever you're cutting get caught between the blades).

I try not to even close the scissors until I get to at least 3k in grit, as it always feels harsh in the action. I'm guessing that lower grit edges won't last nearly as long with scissors, as the edges are rubbing against one another. I'm sure you could take a lot more time on a coarser stone, and get it to work quite well, but it's easier for me to step up to a finer grit once I've flipped the burr.

I find that the bend is often over most of the blade, not just near the tip. Makes deburring on the inside kind of hard, since they don’t lie flat. I usually deburr by rubbing a cork on the edge, or closing the scissors while cutting paper towel to protect the edges from each other. But you have a lot more experience with them than I do.

 

[ian]

I also feel like scissors kill my stones. They steel is so hard.... I have a big old gouge in my Gesshin 6k because of one pair.

 

[HumbleHomeCook]

Several years ago when I was using a KME, I found Dean O on YouTube. He also did a lot of free hand videos and has several on scissors.

I've always more or less followed this and basically what @The Edge said. But, I'm also not overly good at it and have definitely ran into some pair that I just can't figure out and back away from for fear of ruining them. I don't like dealing with scissors, especially nice ones.

Dean O's YT Scissor Vids

 

[The Edge]

I also feel like scissors kill my stones. They steel is so hard.... I have a big old gouge in my Gesshin 6k because of one pair.

Yeah, I have to flatten after doing them, but I'm going through 1-2 stones in each grit a year, so I'm used to it.

I find that the bend is often over most of the blade, not just near the tip. Makes deburring on the inside kind of hard, since they don’t lie flat. I usually deburr by rubbing a cork on the edge, or closing the scissors while cutting paper towel to protect the edges from each other. But you have a lot more experience with them than I do.

I'm usually doing the flat/concave side on the corner of the stone, so that it hangs off a little. This way, there is only a small portion of the stone hitting the scissors, and doesn't change the curve by adding more pressure where it isn't needed. (<- if that makes sense)

 

[ian]

Several years ago when I was using a KME, I found Dean O on YouTube. He also did a lot of free hand videos and has several on scissors.

I've always more or less followed this and basically what @The Edge said. But, I'm also not overly good at it and have definitely ran into some pair that I just can't figure out and back away from for fear of ruining them. I don't like dealing with scissors, especially nice ones.

Dean O's YT Scissor Vids

Nice, those vids look good

 

[DavidPF]

Scissors are a dark art, getting them cutting heel to tip needs the right amount of curvature and tension.

I am very curved (at least in the middle), and I'm quite tense. Theoretically, I should be well equipped. Doesn't seem to translate though.

 

[WildBoar]

@Dave Martell is the scissors whisperer. I think he sharpened scissors/ sheers before getting into the much easier world of knife sharpening. Do a search and you can find a thread or two where he dropped some knowledge.

 

[ian]

@Dave Martell is the scissors whisperer. I think he sharpened scissors/ sheers before getting into the much easier world of knife sharpening. Do a search and you can find a thread or two where he dropped some knowledge.

Yea, those are good threads. Couldn’t find all the answers there, but learned a lot.

 

[HumbleHomeCook]

@ian This actually just popped up in my feed so thought I'd share.

 

[krx927]

There was a thread some time ago about scissor sharpening:

https://www.kitchenknifeforums.com/threads/my-fist-time-sharpening-barber-scissors.41918/