Knife sharpening

[daddyeaux]

What method do you use to sharpen your knives? I have several different knife sharpening devices but would like to know if there is a preferred method to keep them sharp. I also have the jewelers rouge and a stropping stapl

Thanks 

[AzShooter]

I use a medium then a fine diamond stone to get the blade sharp.  After that I strap it with my leather strap.  I use a Tandy HeadKnife and keep it sharp after every project.  I can easily cut through 10 ounce leather.  It does take a lot of time to get it just right.  I sharpened one side of the knife and it didn't cut at all, then I  spent another hour on it and got it to work just great.  

There are a lot of good videos on YouTube to show how to do a good job.  Weaver Leather had one of the best videos.

[zuludog]

My Dad was a carpenter, and I was brought up on oil stones. I inherited his tools, including the oil stones, and added another couple at some time. So now I have a range from coarse to very fine

I follow the fine stone with a strop - 2 mm veg tan on wood, flesh side up, with Veritas green stropping compound

I've tried Japanese water stones and diamond stones, but I don't like them

To a greater or lesser extent knife makers only provide a cutting edge that is basic to adequate, and you are expected to do the final sharpening and polishing yourself. That's one of the reasons that top class knives that are ready to use straight out of the box are so expensive; they've done that for you; but it takes time and effort, and so adds to the cost. However, once you've got your knife into a fit state you usually only need a strop to keep it there, or perhaps occasionally a fine stone 

There are lots of videos on YouTube about sharpening knives, including round & head knives. I like the one by JH Leather

If you use a utility or craft knife with replaceable blades, even new blades re better when they've been stropped

[Spyros]

My main line of defense against the GIGANTIC RABBIT HOLE of sharpening is to avoid knives at all costs and only use things that take replaceable blades: utilty knife, exacto, safety skiver, rotary cutter, strap cutter etc.

If I can't help myself, and I go ahead and buy one of those awesome leatherworking knives (because I'm only human), I then make a nice leather sheath for it and hang it high on my wall to make as difficult as possible to use.   

If all else fails, I begrudgingly do a few quick passes on a couple of diamond stones (typically 800-1600) while avoiding any thoughts of buying a wet grinder that would consume the last usable space on my bench.  And then inevitably I get sucked in and keep dialing in that sucker on the diamond stone, and then the strop, until it can split the wings off a fly into 3 different thicknesses. 

Τhats my 3-step process 

 

Edited August 14, 2020 by Spyros

[Matt S]

I've got a toolbox full of various grit stones, mostly cheap oilstones, for establishing an edge on a new tool or reestablishing an edge on a damaged tool. However for daily use I just strop. A tool starts to snag in the leather, strop it. Tool starts to make noise going through the leather, strop it. Pick up a tool, strop it. Look at a tool, strop it. Think about a tool, strop it. You get the idea.

I was lucky enough to get a basic Tormek machine and it's bloody brilliant. The wet wheel is big enough to only slightly hollow the edge, which is no problem for practical purposes and produces a good edge a whole lot faster than bench stones. Obviously there is no heat buildup like you get with a grinder. As for the stropping wheel I think it'd be worth the cost of the machine on its own. I've barely touched my (perfectly functional) manual strop since I got this thing. In fact I spent an eye watering amount of beer tokens on the extension kit. Those special profile wheels are great at getting into the awkward little bits that are common on leather tools.

[mike02130]

 For carbon steel I use Arkansas stones with a mix of oil and kerosene and strop on MDF or a horse butt strop charged with Dialux green compound.  I find the diamond stones leave too deep a scratch pattern on my carbon knives.  My D2 steel knives I use DMT diamond stones followed up with a Spyderco ultra fine ceramic stone and strop with Dialux white compound.  I have Japanese water stones but only use them on my kitchen knives.

[Rahere]

I go for water stones - use around an 800 for the edge, 1500-2000 for the polish. It depends on how attentive you are to the edge, if you let them go blunt as hell, then yes, diamond roughing out may be a precursor. I sharpen more often.

[chuck123wapati]

i use several methods depending on the type blade and the work it is doing. Most often to put an edge on a typical knife i use oil stones after that i use very hard Arkansas stone then go to a steel,  or 2500 grit sandpaper. It is possible to make sharpening a knife so complicated it becomes overwhelming, I don't do that. 

[Hardrada]

These:

https://www.danswhetstone.com/product/bench-stones/

A soft Arkansas (medium) and a hard Arkansas (fine). Finish with a strop and green compound.

[Danne]

I sharpen my skiving knives with wet and dry sand paper from Mirka on my granite plate. 1000-2500 grit and finish with stropping (Stiff leather with grain side up glued to wood) and green chrome oxide. Skives leather like butter after sharpened.

[Daffy]

I make knives, and sharpen them for folks. 2x72 belt grinder for the straight ones or outside curves (various grits down to strop depending on the steel being sharpened and necessary edge refinement needed.) 1x30 for the re-curve blades with a strop. of course not all steel is equal and some don't power strop well, another story entirely. Straight razors are all by hand and end on a 2500 water stone prior to stropping, where they start depends on how out of shape they are. most leather tools I have are all hand done on a specific sharpening jig of some sort, but blades are blades, the steel dictates the process for desirable results. I like High Carbon steel for it's edge retention properties but it comes with the necessity to maintain it more judiciously.. Steel aside love this wood.... Bocote.

 

[Frodo]

I  just made theses blades today.  they are sharp. will cut leather but are still dull in my opinion. 

I need some 2500 grit sand paper for the next step

 

while i was in the shop i made a belt hole jig

 

 

 

[Retswerb]

On 8/14/2020 at 3:51 AM, mike02130 said:

For carbon steel I use Arkansas stones with a mix of oil and kerosene and strop on MDF or a horse butt strop charged with Dialux green compound. 

Man I like sharp knives but not enough to sharpen them in kerosene. I’ve already been exposed to more than my share of Jet-A, no need to smell like fuel if I’m not getting paid for it.

[Rahere]

Someone once described it as pareto: beyond a certain point, leather doesn't care. Obviously, you've got to get to that point, or you might as well tear it with your teeth. But beyond, I've never yet found a use for human hair shavings, other than as poison.

[olddogTim]

I use a Wicked Edge knife sharpening system. I sharpened my blade for  my Cobra class 14 leather splitter and it came out better than new. I sharpen all my kitchen knives with it. Under a 50 power microscope I get edges better than a new single edge razor blade and sharper

Edited August 24, 2020 by olddogTim
added content

[Spyros]

17 hours ago, Rahere said:

Someone once described it as pareto: beyond a certain point, leather doesn't care. Obviously, you've got to get to that point, or you might as well tear it with your teeth. But beyond, I've never yet found a use for human hair shavings, other than as poison.

Leather is soft generally, grab something a little better than a butter knife and you will cut it.  For me the obsession with sharpness has more to do with the quality of the cut, a nice clean cut means less or ideally no sanding, and better/easier burnishing afterwards.  On thicker leathers it can also mean 1 versus 2 passes is enough to finish the cut.  I don't like that 2nd pass if I can avoid it, it can mess things up if you get it even slightly misaligned with the 1st one.   

Edited August 24, 2020 by Spyros

[Rahere]

It may be you need to examine the quality of your tool. Taking two cuts on anything under 5mm puts that in question, but that's rather a distraction. You can feel a clean cut. I can also feel way beyond there, I use an LDPE undersurface, I'm not into shredding that.

A tool suitable for African Blackwood has to be far more finely tuned than one cutting lumber. Leather's closer to the latter. What I'm looking at isn't simply the right tool for the right job, but the right tool set right.

[Spyros]

Τhe knife is fine.  I prefer light passes because I don't want to risk the leather shifting under the ruler.  It's a shifty material.  

Now don't tell me I need to question the quality of my ruler.  it's fine, it's a ruler, it has cork or rubber underneath.

[daddyeaux]

On 8/22/2020 at 7:00 PM, Frodo said:

I  just made theses blades today.  they are sharp. will cut leather but are still dull in my opinion. 

I need some 2500 grit sand paper for the next step

 

while i was in the shop i made a belt hole jig

 

 

 

That belt jig is a very good idea

[Frodo]

6 hours ago, daddyeaux said:

That belt jig is a very good idea

I got that idea from someone on here,  I saw it and copied it. 

[johnv474]

I own several types of stones and whatnot, but here is what I do.  I am not a sharpening enthusiast, and do not care to sharpen just for the sake of sharpening.  However, I find that VERY sharp knives are a requirement for good leatherwork... or at least for refined leatherwork.

 

First, I only use a few knives.  At any point I could tell you whether a given knife is especially sharp.  A good set would be a McKay type A knife (such as this one: https://www.rmurphyknives.com/store/mckay-stitcher-2-1-8-inch-5-4-cm-shoe-knife-pn-mcky-1-b-details.html ) or a Tina right handed knife (like this: https://www.rmleathersupply.com/products/tina-shoemakers-knife?variant=26075664643 ), and then a head/round knife (Kevin Lee or Osborne are the bang-for-the-buck options, but there are better ones out there for triple the money).

 

That McKay knife is a great trim knife.  For one thing, it is very short so it doesn't go beyond your fingers (which means it is more like an extension of your hand).  For another, the blade tapers and gets thinner, front to rear so you get it into some very tight places (great for starting to cut out stitches, for example).  Third, it's cheap and can get surprisingly sharp.

 

Second, I do not use any sort of angle guide.  The type of abrasive you use doesn't matter but you need to go from coarse to finer and finer.  My favorite overall is to use this set of diamond hones (here: https://www.dmtsharp.com/sharpeners/guided-sharpening.html , the one with the 7 angle guide).  Unless a blade is very dull or damaged, that is a good setup.  For a coarse stone I have a few but just use a cheapo from wherever that cost $10 or so.  Most of the time, my coarse stone is used for reshaping tools like narrowing the teeth on pricking irons.

 

Cheaper than nice sharpeners is to just get some wet-dry sandpaper from an auto body shop or the auto section of Walmart.  Go up to 2000 grit or so.  Tape the sandpaper to a piece of glass or your granite stone so you know the surface is flat.

 

Instead of an angle guide, I go by feel.  I lay the flattest part of the blade on the abrasive and then tilt up just a bit.  I don't care about multiple bevels or anything and would use a full flat grind if it were available.  I am not looking for the longest lasting edge; I want the sharpest edge.  (You basically have to pick one or the other for a given knife).

 

Third, GET A HONE.  Get a butcher's steel.  This makes more difference than you'd believe.  Many times a blade is sharp but the edge is not as straight as it could be.  You don't need sharper, just more aligned.  If you do not have a butchers steel, use the back of a pair of metal scissors or something.  A few passes on either side with medium and then light pressure is all it takes.

 

Fourth, POLISH THE BLADE.  My favorite is to use either green compound on a strop, or a magic eraser + Mother's Magnesium and Aluminum wheel cleaner (from the auto section at Walmart).  Your blade, especially near the cutting edge, needs to be smoooooth.  

 

I leave my strop and butcher steel within arm's reach of my working space.  I will touch up each knife on the steel every day before I use it, and usually give a strop or two also.  This takes seconds.  

 

If I am skiving something down to paper-thin, I might only be able to go a few feet before needing to hone again (a few seconds) and then voila.  If it takes effort, it isn't sharp, polished, or honed enough.  Of course, better knives with newer, better super steels are much easier to keep sharp for a long time.  One of my favorite leather knives is made of S35VN and it holds its edge for a very long time: https://www.kabar.com/products/product.jsp?item=5103

 

 

 

 

[Wayne0820]

The costless may is to use sand paper. Last Friday I did the test with two of my old knives. Since they are dull, I apply sand paper of #120, then #400 and finally #2000. After that, I strap it on leather strap with green stropping compound.

I'm satisfied with the result Easily cut 8oz leather.

 

[McCarthy]

Felt buffing wheel and a loooooong strop paddle. Both with green compound. Also a 1" wide strop specifically for box cutters. I used to do the japanese water stones but now I'm just too lazy. The buffer gets the job done in seconds.