Sharpening - some tips I've compiled

[Andy]

I was asked to write an article some time time ago for someone. I've been tidying it up a little and hope that it will help some people. A fair chunk of it will be a repat of what others have said but there are some tricks that I haven't come across on the net.

Sharpening Andrew Longden

Sharpening goes in hand with owning a quality knife, after all there’s no point in owning a really good knife if you can’t keep it sharp. It’s a much talked about topic and people have different opinions on how it is best done. I do not claim to be the best at this but my results are very good. I do not have a lot of money either so have limited knowledge on some sharpening systems.
Firstly when sharpening a knife you have to look at the knife and how you want to use it, the steel it’s made from and the material you are wanting to cut most will affect the angle of the edge and the finish you wish to achieve. By finish I mean the size of the micro serrations left by the abrasive (I will go into detail later). The grind on your knife may affect how it is best for you to maintain the edge. Though not impossible it’s difficult to sharpen a convex knife on a flat stone so I’m covering that in it’s own section.

Benchstones
The most common form of sharpening system is a bench stone of some sort, these are either Japanese water stones, Oil stones, ceramic and diamond. I have not used Japanese water stones and they require more care and preparation then others. Please seek advice about how to prepare them and care for them. For the sharpening the technique is the same as the others. Some People use oil stones dry and report very good results, however if you use oil once you must carry on using oil or the stone will clog, since all the stones I have were my grandfathers they have all had oil used on them at some point so I can’t comment on the pros and cons of either practice. Bench stones are ideal for flat or hollow ground knives with a secondary bevel forming the edge and knives that use a single bevel per side to form the edge (often referred to as a Scandinavian style grind). Chisel ground knives are sharpened in the same way as the above but you only grind from the side with the bevel.
Press the knife onto the stone so that it forms the angle you want (this can be worked out using trigonometry if your changing bevels). When starting out it’s best to stick to the same angle as the knife already has. This is much easier with knives that only have one bevel per side as you just lay the whole of that bevel onto the stone. Press down with a small amount of force and push the knife along the stone. Many people suggest you imagine that you are taking a very thin slice of the top of the stone. I dislike using this analogy because when you slice something you increase the angle the edge forms with the material being cut which would result in a thicker more obtuse angle being formed. I find it best on concentrating on the distance between the spine of the blade and the stone. I often press a thumb against the spine of the blade and have the thumb just touching the stone as I push the knife forwards. This allows you to feel the angle changing with your thumb. It becomes much more difficult to keep the angle constant when doing the curve (or belly) which forms the tip of the knife as you have to raise the handle slightly. For very small stone (such as the Fallkniven DC03) you can use the same principle but use a circular motion decreasing pressure on the backwards movement. You may also wish to move the stone and hold the knife still. With softer stones it is often beneficial to wear the stone more evenly so when sharpening tips of knives where there is a high pressure on a small area of the stone you may find it best to use a figure of eight type motion. I just move the stone around to try and use all of it at some point. Sharpen one side of the knife until you have a burr along the whole edge and then sharpen the other side until the burr feels to have gone or in some cases moves from side to side with a single stroke on the stone. When you get to this stage I find it best to increase the angle slightly and use a couple of light strokes to make sure all the burr is removed.
If the edge needs major work then a range of grits will be needed. In this case start with a more course grit and form a burr on that side and then a few light strokes using the same grit on the other side. Then use the next grit to more the burr onto the other side until you have a even burr along the edge. This burr should be smaller then the one you had with the courser grit., again push the burr back into line using the finer grit. Depending on the state of the edge (or when your changing the edge angle) you may find that a wide range of grits will make life easier. I tend to use wet & dry abrasive paper for the more course grits as I seldom need them. When using abrasive paper to sharpen a flat bevel I like to use a sheet of glass (such as the flat side of a glass board).

Crock Sticks (sharpmaker)
Crock sticks (where the abrasive stones are held in a base at a fixed angle) are good for sharpening knives where the edge is formed by a secondary bevel, however due to them been fixed at certain angles you are more limited then with a bench stone,. People find it easier to hold the knife vertical then at 20degrees to horizontal though so they have the benefit of ease of use. The best set around that I’ve come across is the spyderco sharp maker which has two angles, 20degrees per side (marked 40 as the sharp maker states total angle) and 15degerees per side (marked 30). It also has a slot in the end which is for scissors but I don’t think it’s any use for sharpening knives.
These are very simple to use as you just hold the knife vertical and pull the knife down the sticks as if you were slicing bread. It’s best to stand up with the base on a table so that you can see the angle the knife is making with the sticks. Don’t apply to much force but concentrate on keeping the angle constant. The advice given with the sharp maker is to do one stroke on one side of the knife and then one stroke on the other side repeating until the knife is sharp. The spyderco sharp maker has two angles and you can also use the corners of the stones. Using the corners increases the force on the edge so will remove more metal but behave like a slightly coarser stone. I find that this makes it more difficult to tell when you should change from the medium grit stones to the fine (or if you buy them the ultra fine) so use a slightly different method.
Assuming I’m bringing dull knife back to a really sharp edge I will use the corners of the medium stones to start with and sharpen one side until there is a burr along the whole length of the other side of the knife. I will then move the burr to the other side. Once that is done I use the flat side of the medium stone to move try and get the burr more even from both sides. This would if left leave you with a wire edge but it gets sorted out in the final step. If a polished edge is desired then I will repeat the process using the finer white stones but I will start from the other side from the use of the medium grit stones to try and keep the cutting edge as central as possible. Once the burr is not at any side you will likely be left with a edge that feels very sharp but wouldn’t last. To remove this a slight increase in angle and the flats of the fine stones will remove the weak metal leaving you with a strong edge. When doing this I alternate between each side of the knife. If the 30degree angle has been used then simply place the stones in the 40degree slots for these last few strokes. If the 40degree angle has been used then something can be placed under the base of the sharp maker to create a slightly less acute angle (a CD case for example).
When touching up the edge I just use the flats of the stones and do one stroke and alternate sides.
Some people find that sharpening the point of a knife on a sharp maker difficult so use it like a bench stone. (This means you can sharpen your other knives on it if this is your sole means of sharpening). If a really polished edge is wanted then it may be easiest to just use the ultra fine rods when your doing the final stage of sharpening at the slightly increased angle.

Convex sharpening
The convex edge has pros and cons which may or may not suit you. If you decide to use a convex edge you may need to relearn sharpening. It can be done on a normal bench stone by pulling the knife spine first along the stone and rocking it so that you remove steel from the whole of the convex edge. If you only remove steel from near the edge over time the edge will be thicker.
The preferred method of sharpening a convex edge is to use abrasive paper on top of something which will form around the convex edge. A mouse mat is ideal, depending on how curved the edge is will determine which side of the mouse mat is best to use. A Fallkniven F1 for example has quiet a steep curve so the softer backing side forms around it better then the hard side. For a Global kitchen knife the harder side is best.
Many people use what is known as a hoodoo hone (named after the internet alias of the inventor). This comprises on a block of wood with a deforming substance (I.e. mouse mat) glued to one side and a method of fixing various grades of wet&dry abrasive paper over the top. I use drawing pins stuck into the ends of the block of wood.
Use a stropping action to sharpen the knife (i.e. the edge is trailing rather then leading). Because the backing deforms under pressure the angle the blade it held at relative to the “stone” is less then with other methods. 13degrees seems to be a commonly given angle. The final cutting edge will be more then this and the difference between the two is affect by the density of the backing. This means the global knife using the hard side of the mouse matt will have a cutting edge closer to 13degrees per side then a Fallkniven F1 would have using the softer side.
This method doesn’t seem to form burrs in quite the same way as other methods, I think this is why some people say it’s more difficult to master. I tend to find it harder to know when to change to finer grits so with this more then other grinds I find it essential that you don’t let it get too dull before you sharpen it. Since stropping a knife convexes the edge slightly you can maintain this grind fairly well just with that. I’ve also taken to just touching up the edge using a sharp maker (flat sides of the white rods) or freehand sharpen using hard backed wet & dry paper. I only do this a couple of times before getting out the mouse matt though.
This grind to me seems the ideal one for a kitchen knife as it excels in slicing. With a kitchen knife the edge tends to be thin enough that you can just sharpen it like it already is convex and soon enough it will become convex. If you want it convex straight away then 320 or even 240 wet & dry will sort this very quickly.
One problem with this grind (for me anyway) it that it seems to be very difficult to change the original grind angles unless you have a belt sander. One method I have tried with fair results was to use a bench stone and grind metal away from behind the edge at a few different angles and then blend them together using course wet &dry. It’s a lot of work though and I’d rather just find a maker who could do it for a small payment and a lot less effort (on my part).

Sharpening recurves
There are a few knives about with recurve blades and most people seem to get a bit concerned about sharpening them. These methods will also work for spoon knives which would work best with a highly polished edge
To sharpen them you can get away with using the corner of a bench stone but I don’t like doing this. Once again the sharp maker can be handy but for a kukri it’s rather difficult to use the base (it’s fine for little Kershaw knives though). A ceramic or diamond steel will be much better to hold but it’s something extra to by if you don’t already have one
I use either the sharp maker rods or some wet & dry paper wrapped around something round. The sharp maker rods are fine but aren’t very good for holding if your doing any more then touching up the edge. Also since you can only use the corners there is a tendency to put more force on the edge then there it with the wet & dry.
The radius of the curve your sharpening will to an extent determine what the best thing is to wrap the abrasive paper round. For a tight curve a piece of 20mm dowel can be used. In this case it’s best to have enough dowel for you to have a handle on the end of the abrasive section. I don’t use this all that often as I’ve found that I need to glue the paper to the dowel and normally I can get away with a bigger diameter cylinder. If I can’t I’ll just use a ceramic rod.
At home you can use a glass jar with a smooth side. This gives a very good hard backing for the paper if your wanting to keep a flat secondary bevel and will also give you enough to hold onto and you can normally hold the paper against the jar without having to glue it. If you want a small bit of tape should hold it in place and can be easily removed once your done. Normally I use a plastic spice pot. This will give a little so will result in a slight convex edge. This is ideal for the kukri that I sharpen with this method but if your careful you can just use the part closest to the ends where the pot wont deform so much. What I like about the spice pot is that it gives you a water tight place to keep a range of wet & dry paper in as well as other bits and pieces for knife (and sheath) care.
With any of these devices I find that it’s best to keep the knife still and move the sharpening device (of course if it’s a small blade then use the sharp maker as normal). I tend to use a circular motion but apply force on the backwards stroke with the glass pot or ceramic rod while I use more force on the forwards stroke with the plastic pot. This gives the same effect as edge leading on a bench stone and edge trailing when using a mouse pad to sharpen a convex edge.
You can if you want wrap a piece of leather round a pot and use as a strop but I normally find the ultra fine abrasive paper enough.

Sharpening serrations
Most serrated knives now come with a chisel ground edge, i.e. one that is only ground from one side. This means that you normally only sharpen them from one side as well so all you have to do is sharpen the side that is ground and the strop from the other side.
Most serrated knives have a regular semi circle type pattern to them (e.g. a victorinox Swiss tool) while some brands use patterns of different shaped grooves e.g. spyderco has a pattern with one large and then two small serrations. Both of them can be done with a spyderco sharp maker but most can also be done with a small round hone (normally diamond).
You can just run the knife down the hone in the same way as you would with a plain edge but there is a tendency to remove metal unevenly and not sharpen the insides of the serrations as much as you could. Use slow gently stokes and maker pen to make sure that you’re not just grinding away the ridges of the serrations. With major sharpening of a blade like on a Swiss tool I use a small stone and do each serration on its own and then finish off using a normal stroke. I haven’t found anything other then a spyderco stone that gets into the small serrations of the spyderco knives and as these aren’t that aggressive I’d be careful not to let them get dull before sharpening.
When stropping the other side I lay the knife on the strop so that the entire primary grind is in contact so that I don’t round off the points of the serrations. Some people like to use a leather shoe lace or the corner of a piece of leather to strop the ground side of a serrated blade. I’ve tried wrapping a shoelace round a block of wood to do a large number at one time but haven’t had much success doing that.

Stropping
This is the final part of sharpening which is sometimes left out if you want a more toothy edge (larger micro serrations). Some people feel that that to ensure you have the best edge possible you should take all edges to the highly polished stropped finish and then go back to a stone for a few strokes if your doing something like cutting rope. I don’t bother but if people have trouble completely getting rid of the burr then it may come in handy. Stopping is normally done using a piece of leather (such as a belt) with some mild abrasive rubbed into it but is sometimes do with paper or cardboard.
There are two basic methods of stropping. One is to secure the strop at one end and hold the other tight (such as holding one end of the strop on the floor with your foot and the other end in you hand), the other is to lay the strop on a hard surface. I prefer the second method as I find that people often end up rounding the edge too much if using the first method and then you have to start sharpening again.
With either method you pull the knife along the leather with the edge trailing. I do a few strokes per side and then swap, at the end I’ll only do one stroke per side before swapping over. Be careful not to raise the spine too much, I like to start off with the knife at the same angle as it was when sharpening but may raise it slightly depending on how much the strop deforms. A common mistake made when stropping is to raise the spine at the end of a stroke, it’s really important that you don’t do this as it will dull the edge rather then make it sharper.

Steeling
Normally only used on kitchen knife blade but is suited to all knives depending on what you want them to do. Steeling a knife is in a way the alternative to stropping a knife in that it is the final stage of sharpening and something which should be done between proper sharpening. The effect of steeling is that it relines the edge like stropping but while stropping will also polish the edge and slightly convex it steeling wont. This makes it the finish of choice for knives where micro serrations are wanted (cutting meat for example).
There are two main groups of steels, finishing steels which are smooth and sharpening steels which remove a small amount of metal. The popular steels seem to be diamond or ceramic. Of the two I prefer the ceramic steels but I find most people can do a better job with crock sticks. If you only have a steel then you may find it easier to hold the steel at an angle and keep the knife straight up or down (or depending on what you rest the tip of the steel on you could hold the knife horizontal). For example a right handed person would hold the steel in their left hand. If you hold the steel with the tip pointing down on a chopping board at 20degrees from vertical you can sharpen the left side of the knife. If your sitting down you can then support the steel against a table and sharpen the other side, If your standing up you can hold the tip against a wall. When doing this it’s best to have a steel with a guard.
A smooth steel is just that. I tend to just use a glass rod (though it’s more difficult to hold and has no guard so isn’t the best thing for beginner). I’ll use this in the same way as described for the sharpening steel but may hold it at a slightly greater angle then the edge bevel is at (only a couple of degrees though).
Some people feel that when steeling (or at least when using the smooth finishing steels) it best to have the edge trailing. This is meant to reduce the risk of dulling the edge against the steel by trying to make it bite into the “steel”. I haven’t found it to be any trouble but if you want to steel your knife with the edge trailing then I find it’s best to learn by sitting at a table and holding the steel with the tip slightly up when working on the left side of the knife and the handle slightly up when working the right (if your left handed reverse).

Tips
checking edge angle
To make sure that your getting the right angle you can put some lines of felt tip perpendicular to the edge. If the felt tip is not removed evenly along the length of the blade then your not keeping a constant angle. This can be difficult when using a wet stone as the oil or water will wash the pen marks off so when first sharpening a knife I like to use some fine (1500grit) wet & dry paper on a hard surface and then once I know that I’m removing the felt pen in the right places I’ll use the courser oil stone. If you have ceramic bench stones or a sharp maker then you can just use the white stones. Some people like to put felt pen along the whole edge but I prefer to just do a few lines as it means my sharp maker doesn’t need cleaning so often.
If your wanting to make sure the angle your sharpening at on a bench stone is the same as your sharp maker (handy when removing a lot of metal without the diamond rods) then you can put a line of felt tip every inch or so (I put a line every inch and a half along the straight edge and closer along the belly of the knife). Remove a little bit of this lines using the sharp maker and then put a new line next to each one. If the new lines get removed in the same places then the angles are the same.

inspecting the edge
A small magnifying glass can be useful for inspecting the edge of a knife. If the edge feels sharp but behaves differently in one place then you may have micro chipping in the edge. It’s easy to seem if you have a ten times magnification. The best thing I have found for this is a special one designed for people with poor sight which has a light built into it.
You can check for dull spots in a knife edge by holing it in the light. If there is a point on the edge where light gets reflected then in that place you either have a fault in the edge.

checking for burrs
If the final sharpening edge is at a constant angle then it’s possible to get a small amount of light reflecting from the edge bevel and as you move the knife this light will appear to move along the knife. If there is a gap where it doesn’t then inspect it with the magnifying glass. On occasions there appears to be a tiny chip out of the blade but one which doesn’t go through the whole cutting edge. This will leave the edge weaker and prone to chipping so it’s worth keeping an eye on. I don’t normally bother sharpening them out unless it does chip though.

Sharpening the tip
You should have to raise the handle from the stone to match the curve of the blade but if you look carefully at the handle you should notice that in one plain the angle doesn't change. I'm not sure I'm about to explain it very well but I'll try
If you look at a cross section of the handle (assume you have a flat handle for this) then when the straight edge of the knife is in contact with the stone the top of the handle will be elevated. If the handle and the blade have the same depth then this difference would be the same as the distance between the centre of the blade thickness and the stone. (if the handle was 30mm form the top to bottom and your sharpening at 20degrees then the spine side would be 10mm higher the side by the cutting edge.
When you’re sharpening the belly the handle gets raised but if you were to draw a line from the top to bottom the top of that line should still be 10mm higher then the bottom.

 

[tomtom]

nice one Andy!

 

[Stuart]

thanks andy

I think I'll sticky this

 

[Ditch Monkey]

Thanks Andy

 

[Amon81]

Good article.

One thing I will add about stropping. You can get very good results without using an abrasive too.

But if you really want a propper finnish I've always found it best to strop with and abrasive (I use white Aluminaoxide, a buffing wheel compound) then just with plain leather.
This creates and amazing edge that will (if you are not carefull) shave the skin off your arm along with an hair you try to shave off.

A 6000 girt Japanese water stone and a good strop is a methord I've found impossible to beat. For about 15-18 years (growing up basicly) I used fine oil stone, which worked great, but after I invested in Water stones I'm never going back, they just take the egde to the next level.

Like with everything it just takes practice.

I use O1 carbon-steel as much as I can, but I've found for me I get the best results sharpening stainless steel with an 800 grit and not polishing them off with the 6000 as it just dulls them again. Same with my golok, 800, but I then polish it with the smooth side of a DC4, I like my golok to just about be able to cut paper, sharper and it dulls too quickly when used on dry wood.

 

[jimford]

An interesting and useful post.

I see arkansas stones are not mentioned. Anybody have any comments to make on them?

Jim

 

[bush tycoon]

Great post. i was going to put up a post regarding sharpening technique but glad i saw this. Thanks

 

[wildjim]

Great information!

This what works for me. . .

I've settled using a large ceramic rod much like a stone to sharpen an edge that is already straight and just dulled from use.

If the edge is damaged or uneven I used a 1x30 belt sander to fix and straighten the edge then go to the ceramic rod and sometimes a leather strop to remove the burr.

Also I sometimes use a Paper Wheel on a grinder shaft doped with jeweler's rouge to polish and or straighten the edge.

 

[Blacklamp]

i have a question....when sharpening my knife, which is holding a flat grind, i get to the stage where i have kept the angle on my bevel the same all the way up to 6000grit on my waterstones. however even though 90% of my cutting edge is fine (ie highly polished and relatively symmetrical, and scarily sharp!) a little segment closest to the handle is corse and dull, to the extent of being visibly noticeable (the cutting edge head on kinda looks like this: -----------------~~[handle....if you get what i mean!) so much so i can't cut paper cleanly.

i've tried re-sharpening it but this time starting at a lower grit (i used a piece of 400 grit wet dry attached to a flat board) and then working my way up through the grits...but the same thing keeps happening, even though the rest of the blade is razorrrrrrrrrrrr sharp
i don't want to keep resharpening and wear out the blade...any help would be much appreciated!!!!

 

[JonathanD]

A picture would be really helpful.

 

[Dave Budd]

it happens because that part of the blade isn't in contact with the stone for as long as the rest basically if you are sliding the blade sideways at the same time as forwards in order to cover the length of the blade, that bit gets missed! Often people don't apply the same force when the start or end the stroke, so that can cause a spot at either end of the blade to be missed too.

Try just running the blade straight up and down the stone for a few strokes, so only the first part of the blade is worked on. then continue with your normal strokes and the two motions will blend the edge in to good.

of course, it could also be that the blade is slightly hollow ground and that part of the blade hasn't worn to flat yet, hence the lack of polish.

n.b. don't get hung up on having a uniform polish. a knife is meant designed to cut stuff, not for you to do your makeup in! So as long as the angles are right then the only bit that needs to be finished properly is the edge: the rest of the stupid great scandi bevel is not doing much as long as it's not so rough it causes lots of drag.

 

[Blacklamp]

Much thankssss!!!!!

 

[Bartnmax]

Excellent thread.
I've alway believed that if you're going to own a decent blade you need to know to sharpen it properly.
First of all you need to underdtand the difference between oil stones, wet stones (water stones), & diamond stones.

1. Oil stones are generally made from either Aluminum Oxide, Novaculite, or Silicon Carbide. Novaculite is a natural substance, often quarried in the Arkinsaw region in the US (hence the name 'Ankinsaw Stone'). These can come in various grades & are generally the fastest cutting of the oil stones. The next fastest are the 'India' stones, which are artificially made from either Aluminium Oxide or Silicon Carbide, & again they can come in various grades. Of the three main types of sharpening 'stones' these are actualy the slowest cutting stones, but their advantage is that they are usually cheaper than good wetstones & Diamond stones, they are harder than wet stones & therefore wear than wet stones better (but less so than Diamond). They are also messier to use than either wet stones or Diamond stones.

2. Wet stones (often refered to as 'water stones'). These may be made from either natural or artificial materials. The artificial material used is Aluminium Oxide (same as the oil stones) but the difference is in the bonding material. An 'India stone' whilst being Aluminium Oxide is always an oil stone & never a wet stone.
These stones wear faster than oil stones but due to that wear the swarf is also carried away better & so they cut faster. The main downside is the afore-mentioned faster wear rate of the stone itself. They are also usually a bit dearer than oil stones due to the bonding material used & the greater effort to finish them during production. If used with oil they will quickly clog up & hence stop removing swarf (metal fillings). Once that happens the stone doesn't sharpen properly & may in fact damage the edge minutely as well as accellerate the wearing of the stone. It has been said that often water evaporates from wet stones when in use. I dont believe this is the case. I think it's more a case of the water soaking in due to the porosity & softer composition of the stone. I've also seen similar with oil stones but I reckon I could pretty safely say that the oil will never get hot enough with hand sharpening to evaporate. Again, it's a case of the lube, in this case the cutting oil, soaking in. The best way to lube these stones during use is to just have a bucket of water next to the bench the stone is on. Regularly dipping the stone into the water to wash away the swarf will maintain not only better cutting but it will minimise wear. Eventually when they do wear they may need refinishing (or replacement). Refinishing is usually carried out with a Diamond stone or cutter.

3. Diamond Stones - made from? You guessed it, - Diamonds.
There are two main types of Diamonds used. 'Dimpled' stones which contain minute holes which capture the swarf & are extremely fast in their cutting rate, & 'continious' stones which are usually used to sharpen very fine blades such as scalpels, etc.
Due to their hardness Diamond stones dont generally suffer from wear so much but they can be damaged by poor handling.
They are often used to re-finish both oil & west stones. Their main disavantage is their higher cost.

Which is best for you? That depends a lot on personal preference but also on what type of blade you're trying to sharpen & the material construction of it. Lastly it also depends on how much you can afford to spend when buying a stone.
Generally;

1. Oil stones are cheap, wear reasonably well, but are messy & sharpen slowly.
2. Wet stones generally sharpen better than oil stones but are a bit dearer & wear faster than oil stones.
3. Diamond are generally the best of the three but also the dearest to puchase.

Bill.

 

[Bartnmax]

There are a couple of common problems that many people have when trying to sharpoen their blades.
The first is not understanding the difference between the various stones, & therefore they also don't understand how to use them properly.
The second is in maintaining the correct angles whilst they work the blade against the stone.
Get the stone use right & maoinbtain correct angles & it's not hard to sharpen a blade at all.
Use the stone thr wrong way or not maintain correct angles & you can actually blunt the blade worse than when you started.

For those starting out I usually recommend the use of one of the Lanksy type kits as they come with a blade jig that ensures correct angles are maintained. Once you get the idea of what angles to maintain & ho to do so it's not hard to move onto sharpening with other methods.
There are now a number of manufacturers makin these types of kits & they really are brilliant. So easy even a child could put a scalpel sharp edge on a knife with very little effort.

Oh, and really, whats with this idea of testing a knife by shaving the hair on one's arm?
The best way to check it is to lightly drag it across a thumb nail. You'll feel it drag as the blade cuts lightly into the cuticle.
Shaving hairs on one's arm is only going to work in taking the edge off a blade.
I'm pretty sure the major knife manufacturers don't employ people to shave the hair off their arms to test the knives made.
Slipping whilst checking a knife with the 'shaving' method can lead to all sorts of embarrassing questions as the doc stitches you up.
And if it happens when you're camping it could lead to some nasty infections.
Knives are for cutting. Shaving with em could result in them doing exactly what they're supposed to - cut.
Don't do it ;-)

Bill.

 

[Elines]

.........................Oh, and really, whats with this idea of testing a knife by shaving the hair on one's arm?
The best way to check it is to lightly drag it across a thumb nail. You'll feel it drag as the blade cuts lightly into the cuticle
....................................
Bill.

? ie by dragging it from the 'pale semicircle' of the thumb nail to the nail edge

not

dragging it along the thumb nail edge

 

[gentlemanc]

Can anyone give advice on sharpening a spoon knife, I cannot seem to get my head around it?

 

[thedawnawakens]

Can anyone give advice on sharpening a spoon knife, I cannot seem to get my head around it?

Jason from woodlandways demonstrated this to me by finding the angle then instead of going across the stone with the blade ( like one would with a straight blade), you simply go up and down a single section at a time on the spoon knife until you're satisfied with it. I hope that made sense. It works on mine

 

[JimboJames1972]

Andy, and others,

Thanks for this info, for a newbie like me is is always good to lean useful tips!

I have a question relating to the grit ratings of different abrasives though. We refer to wet and dry papers as 800 grit, 1200 grit etc and I am happy with that. However, the water stones I have been thinking of buying are rated between 1000 and 6000 while diamond sharpening stones seem to be rated a lot lower (200 for coarse up to around 600 for super-fine/honing). How come there is a ten-fold difference in the ratings for water stone honing stones and diamond honing stones? Is it the different way they cut, the different finish you get or are they using different units?

James

 

[Dave Budd]

its mostly because the diamond grit comes off, leaving the things relatively smooth after a couple of uses. Basically, they start coarse and aggressive and wear to smooth, before becoming ineffective in the centre with coarse ends!

There are different units and meshes used between different abrasives, but most that you will come across are similar enough.

 

[nic.]

A bit Harsh Dave! although lots of diamond stones do wear out at a frightening speed that is hardly the reason that they are generally coarser. The main reason is that it is very difficult to accurately embed very small diamonds consistently. The guy I deal with guarantees his stones for 5 years, these diamonds are electroplated in with nickel and they have had no success in doing this accurately under 1,000 grit. A shame but the stone I have is still cutting well after three years and I guess I use it more than most. Broadly speaking the grits are comparable.