How Do You Keep Your Knives Sharp?

[Flask]

Hi all

I am able to put a good edge on my knives using sand paper (emery cloth), and finishing with a strop, but looking for a faster (easier) way and thinking of buying a buffing wheel, wondering if this is a good idea, and if people here use one to put or keep that razor edge on their knives?

Thanks

[gmace99]

I use an oil stone and strop a few times a year I use the buffing wheel at least once a week. Keeps my knifes very sharp

[Red Cent]

http://www.tools4flooring.com/personna-pro-63-0222-folding-carpet-knife.html

http://www.irwin.com/tools/utility-knives-blades/irwin-fk150-folding-utility-knife

The top one utilizes a thin blade (less resistance) with 4 corners and can be rotated and will last a long time. For straight cuts or flowing lines cuts better than a utility knife. I use the second one for sharp curves or, heaven forbid, tight corners.

[DavidL]

DMT stone then water stone. After im finished sharpening I flatten my water stone with DMT stone.

Lower rc knives use a steel to "sharpen". Im not sure if a knife with low rc is not as sharp or if knife edge life is the only downfall. If the latter is the case I may pick up a low rc knife just because steeling a knife is fast and sharpening would be quick too.

[Itch]

We use a piece of leather flesh side up. Rub it down with bee's wax and then sprinkle with aluminum powder on the other end we rub red rouge it keeps our knives very sharp ..

[Sonydaze]

Between needing to sharpen leather working tools, woodworking tools and kitchen tools I went to the Tormek system and am quite happy. Their jigs take the guess work out of keeping the correct angle and take you back to the same angle time after time.

http://www.tormek.com/en/machines/t7/index.php

[BondoBobCustomSaddles]

Like the old cook in Lonesome Dove says, "a good knife is like a good wife, you have to strop her every night!"

Bob

[dikman]

DavidL, I'm not sure what you mean by "low rc"? Carbon steel blades, as opposed to stainless steel blades, have long been considered by many to be superior in "sharpenability". They may not hold an edge as long as stainless, but they are easier to sharpen and steeling them, or in our case stropping, often should keep them sharp with a minimum of effort. The downside, of course, is that they will rust if not looked after.

A buffing wheel can certainly be used to hone an edge - as long as you know what you're doing (a high speed buffing wheel can be an extremely dangerous device if you're not careful). It can also round off an edge, and in extreme cases destroy the temper on thin blades if you get them hot.

[DavidL]

I dont know if low rc is the exact terminology but steels that are in the 30-45 rc that get a sharp edge with a steel where a japanese steel at 64 works better with a stone. Looking at your avatar I can see you make knives. What is you take on a knife in the 30-40 rc range. Is it sharp enough to cut leather well. All I know about knives like this are they are used mostly by chefs because it can be used with a steel.

[Art]

I dont know if low rc is the exact terminology but steels that are in the 30-45 rc that get a sharp edge with a steel where a japanese steel at 64 works better with a stone. Looking at your avatar I can see you make knives. What is you take on a knife in the 30-40 rc range. Is it sharp enough to cut leather well. All I know about knives like this are they are used mostly by chefs because it can be used with a steel.

There are just too many things here to formulate a reply without writing a book.

The steel as used in meat cutting and food preparation has morphed over time. In the last 30 years, I have seen things made of steel that have an abrasive surface (sometimes even diamond) that are called steels. These "things" actually remove metal. You don't see them in meat cutting, but many chefs allow them in their kitchens because they will "sharpen" a useless knife to the point where it can be passably used for fifteen minutes or so. These are the chefs who also try to save money by foregoing a regularly scheduled sharpening service.

A proper steel is a rod of 1040 to 1050 with a good heat treat and a draw to HRc 50-55. This design is used to straighten the edge (make it stand up) that has been slightly rolled, more like bent over a little. This allows the meat cutter to use knives with 35-40 degree included angles (very sharp) to keep them sharp from the start. You can't wait till the knife is dull to use the steel as once the edge is gone it has to be sharpened, there is just no other way except maybe to limp along with one of those abrasive steels.

If there is a mismatch between the hardness of the steel and the knife, it makes little to no difference as you are just standing up the edge. A 62 HRc knife can be steeled by a 40 HRc steel and vice versa without any noticeable difference.

Butchering knives have to be hard to stand up to bones and other hard things like chainmail gloves. If you have ever seen how knives and other tools and implements are handled in a restaurant, you will understand that the blades need to be hard. All these Chef shows on TV make people think the Chef goes to work with his roll of beautiful knives. If that ever happened, those knives went home that night and were never brought to the kitchen (except maybe the one at home) again. Mundial, Dexter-Russell, and Forschner are the three knives I recommend and have never had complaints (there is so much crap out there that a Forschner looks like the knife gods might have dropped it from knife nirvana). They sharpen well (professionally) they are hard, and they last. Dexter-Russell still makes the best steels Number 1412B or Number 1458B, which are both 14 inch and go for around $30 at FSW.

Knives have been the subject of voodoo forever. Some knifemakers will tell you all this exotic crap about their knives and how they are made, and how the steel was passed down from the gods by meteor, but folks who make them because they like to will tell you, buy steel, cut (or grind) out what don't look like a knife, heat treat, and make it pretty. There is some science to it, and many ways to mess it up, but it ain't rocket science, and if you screw-up enough of them, you learn how not to.

Butchers and Chefs in general know little about knives other than when they are sharp, when they ain't, and what NSF means. I wouldn't be asking them about knives and construction, only on use. Get real info from a knifemaker or a sharpener.

Art

[dikman]

Dave, while I've dabbled in knifemaking I definitely don't consider myself a knifemaker (in comparison to those I meet at knife shows). I did it more out of interest, in order to learn how to make one. In the process I've learned a lot about cutting tools and edged weapons, and a bit about sharpening them. (My real interest is Samurai swords).

Art's comments about the "voodoo" bit made me smile, because that's certainly been the case in the distant past, but fortunately there is now enough information out there to dispel those myths - if you look, that is. I've also found that knifemakers here are a very generous lot when it comes to sharing knowledge. Also, he's right about the abrasive steels, they are usually diamond coated and work well (I've got one, because in our kitchen it's almost impossible to keep a sharp edge on the knives (!) and being stainless knives are a pain in the butt to sharpen). But a professional wouldn't use one in a fit.

Basically, if there's enough carbon in the steel to harden it then you can make a cutting tool (knife) from it. Too much carbon and it can get brittle, too little and it won't harden. As for sharpening, some swear by water stones, some like Arkansas stones, ordinary oil stones, diamond plates - whatever works for you. For cutting leather, however, a strop is probably the best way to get that final edge that's needed. I've found that thin blades work better, and I've been using scalpel blades lately - very thin, so can flex a bit but man, do they cut!!

[DavidL]

Samurai swords are amazing pieces of art for sure. Its amazing how they were able to perfect the edge of swords way before any testing and modern equipment is available, all trial and error. I believe even to today's standard they still are up to par or above what is out now. Plus all the patterns that are made by folding and blending different steels.

For cutting leather, however, a strop is probably the best way to get that final edge that's needed. I've found that thin blades work better, and I've been using scalpel blades lately - very thin, so can flex a bit but man, do they cut!!

I think after reading these posts I will go back to a olfa box knife. I've tried stainless steel custom clicker knife, japanese kiridashi and the cheap olfa still cuts better than them all.

[dikman]

I won't start a discussion on Japanese swords, but yes, they have been described as the pinnacle of sword making.

As for the boxcutter, if it works for you that's all that matters. I have found that cutting leather, particularly thicker stuff, is a lot different to cutting other materials, and some of the implements that I thought would work have proven to be quite inadequate. I now have an odd assortment of blades that I use - Stanley knife, el-cheapo box cutter, cheap "hobby knife" kit off ebay that will take scalpel blades, disposable scalpels, Olfa rotary thing and basically anything else that I find that might work. Best thing I've found, though, is using the strop that I made - it makes a heck of a difference to blades that are used to cut leather.

All good fun.

[Colt W Knight]

Samurai swords are amazing pieces of art for sure. Its amazing how they were able to perfect the edge of swords way before any testing and modern equipment is available, all trial and error. I believe even to today's standard they still are up to par or above what is out now. Plus all the patterns that are made by folding and blending different steels.

I think after reading these posts I will go back to a olfa box knife. I've tried stainless steel custom clicker knife, japanese kiridashi and the cheap olfa still cuts better than them all.

Modern steels are far and away better than old Japanese swords. In fact, swordsmiths had to do all that "mystic" forging and folding to make up for the fact they were using such poor quality steel. Japanese swords were much thicker than european swords. I'm not saying they are bad artistically or functionally, but they are not on par with modern steel. Equally if not better swords were being made in Europe during the hay day of samurai swords. But ninjas and samurai are cool, so they get a lot of voodoo points.

I sharpen my tools with either a Norton stone or my diasharp stones. Then I keep them sharp with my steel or strop. When stripping doesn't get my swivel knife sharp anymore, I hit it on some 1500 grit wet sand paper. That way I don't have to drag my stones out.

[zuludog]

My Dad was a carpenter and I inherited his oilstones; one medium, one fine. No idea what grit size or make they are, but they do the job. They're OK for woodworking tools but for leatherworking tools I also use a homemade strop, made from scrap wood and leather.

I use Autosol car chrome polishing paste on the strop, but when it is used up I'll look for something more solid like a block of jeweller's rouge or a specialist buffing compound

I cut my leather with a Stanley knife. I've found one with a comfortable handle and a few blades that fit well without wobbling. I resharpen the blades on variations of the two stones and strop as required

The cutting seems to improve as the blades are resharpened, probably because it reduces the shoulder of the bevel, and stropping produces a polish that is higher than the original blades