View Full Version : How sharp... does it really matter?
We all talk about how sharp our knives, axes, billhooks ( supreme tool) and saws are and how proud we are that we have achieved this level of skill.
Your edge tool will cut paper and shave hairs of your legs but the question is this;
....does it really matter how Sharpe your edge is, you can spend hours putting a fine edge on your tool only to take it out into the field and get a dink in it as the edge is so fine. You then spend another hour or two working the dink out of it.........until next time you take it out in the field and then you get a dink then.................can you see a pattern forming here?
So is it worth the hassle?
Cheers.
Jack.
Rhapsody
23-08-2005, 15:32
Well I can sort of see what you mean when you're talking about an all-purpose do-all knife because, let's face it, we need that sharp, butnot shaving-sharp. However, when you're using your knife for any kind of non-trivial carving, as I imagine most of us here do at some point, then you'll want it as sharp as possible. The difference a razor's edge makes when whittling is astonishing.
mojofilter
23-08-2005, 15:49
I see what you are saying, but an edge doesn't need to be super fine to be sharp. A thick steep edge can still be made razor sharp, and be more durable. Obviously though, cutting ability is better with the fine edge, but there must be some form of comprimise between cutting efficiency and durability.
I was surprised when Ray Mears (on Buschraft Series 1 DVD, I think) stated that a very sharp knife will stay sharper for longer than a blunter knife. But it might make sense, as long as various assumptions are correct e.g. the edge isn't so fine that it doesn't curl over at the mere sight of something to cut.
Like most of us, I appreciate a sharp edge, but then I'm not too obsessive about it. My kitchen knives will gradually blunt, and I'll notice it only when, for example, I have trouble cutting ripe tomatoes. But that can be after a month or so, not the fastidious daily honing of a sushi chef.
My straight razor, however, must be kept insanely sharp otherwise it's not worth trying. I'm a little more fastidious about that.
Perhaps ask me again when I've spent lots of time in the field (I'm still very much a novice at this bushcraft malarky) and I can have more of an idea of the benefits of a super-sharp knife in the bush.
Think of it this way:
A surgeon's scalpal will be sharpened to a very fine angle, a razors edge. Why? Because he needs it sharp to cut soft flesh, so massive edge retention is not necessary.
A general use knife, perhaps a SAK, a Schrade, or a Buck is sharpened at a medium angle. Not too fine, not too coarse. The edge needs a bit more wear resistance to aid in the blade cutting harder materials than the surgeons scalpal.
An axe (Gransfors Bruks anyone?) will be sharpened at a very low angle. Why? Because it is not needed for extremely fine work, and will be used on extremely hard, and edge degrading materials. The lower the angle, the lower the cutting resistance, but the higher the edge retention.
Keep in mind this also:
The angle is not so important as the CONSISTENCY of the angle.
Right?
Adam.
Keith_Beef
23-08-2005, 16:45
I think Mojo got it right, when he mentioned that you have to compromise between thin edge and thick edge, but both can be very sharp.
I believe that a blunt knife is more dangerous than a sharp knife, because you put more effort (more force) behind it to make it break through the material you want to cut. You can easily put more and more force behind it, until finally it breaks through in an uncontrolled way, and you have an accident.
Keith.
I think it is important to always have a sharp knife handy. That's why the old timers carried a variety of cutting tools and usually kept one razor sharp. There are some tasks a moderately dull knife just won't do. But I don't believe a knife has to be hair-shaving sharp all the time to be useful. I've had many thin-bladed "dull" knives outwhittle thicker blades that were shaving sharp.
http://www4.gvsu.edu/triert/cache/articles/t1/Grohmann_pic1_v4.jpg
bushwacker bob
23-08-2005, 17:53
Every time I see that picture I am more impressed :)
The critical thing IMO is a polished edge. A toothy edge, although better for some things, won't last as long as a highly polished one. For that reason i always top up my edge with a...urm...loaded strop. :)
mojofilter
23-08-2005, 21:12
An axe (Gransfors Bruks anyone?) will be sharpened at a very low angle. Why? Because it is not needed for extremely fine work, and will be used on extremely hard, and edge degrading materials. The lower the angle, the lower the cutting resistance, but the higher the edge retention.
I think you would be surprised at just how fine the edge on a GB axe is!
I've just checked and my scandi doesn't shave at the moment. I haven't noticed much difference. I find the handle of a knife the gives me most cause for concern but I try and get that right when I buy them. It's much easier to use a knife that isn't quite so sharp if it's kind to your hands then one which is very sharp but hurts to use with much pressure.
IMO people (including me) spend far too much time thinking about how long the steel stays sharp the angle of the grinds etc etc when how it fits in your hand seems left out for the most part.
I agree Andy - I have a beautiful custom made knife with a blade to die for, but I am back to using a mora at the moment, because the handle on my custom is just not right. So there it sits....
BlueTrain
24-08-2005, 12:06
You might be surprised at what country people did with their blades around where I grew up in West Virginia (more than a few years ago).
First of all, you could say people did not baby their tools. Axes were frequently left outside at the woodpile. But those folks were all widows not looking too far into the future and, besides, they only used them to split wood, never to cut much of anything. I don't recall people having much in the way of knives beyond a pocket knife. There wasn't much hunting then. However, mowing sythes were still common, even if they weren't used to cut large acreage. There were various sorts of blades, depending on what you wanted to cut. Now an interesting thing about sythe blades is how thin they are. They hold up fairly well, provided the user holds up his end and doesn't run the blade into the ground or attempt to slice stones, which grew very well around there. A significant point, though, is that the person using a sythe always carried a sharpening stone with him and he would run it over the blade a few times, oh, maybe as often once every half-hour and maybe more often. I suspect it was as much for the break from mowing as for sharpening.
I haven't seen anyone using a sythe since I left home.
These days I have a nice collection of not very nice knives, none costing over $50, shipping included. In the woods, camping, I seem to find ways to do without requiring a knive very often. But that is evading the issue. When I want the knive, it needs to be sharp. It is a little irritating and a little embarassing to find your pocket knife has trouble cutting a 1/4-inch cord or slicing open a plastic package. Here at work a pocket knife is handy for opening boxes but that's about all.
Now my kitchen knives are another story. They also need to be sharp and they get used all the time. So I tend to use the sharpening steel almost every day just to touch up the blade. I couldn't tell you the first thing about angles or whatnot but I know it makes a huge difference in how they cut.
Another thing is, most of my knives are stainless. They might be harder to sharpen but it is easily worth it to me just to prevent rust. I don't have anything with a fancy finish of any sort.
Speaking of knives, I have noticed that my wife will always pick a different knive than I would to do the same chore. We are like that, I guess. As a matter of fact, there aren't two things I can think of that we do the same way. Different backgrounds, I guess. Anyway, she has managed to remove the serrations on a couple of paring knives by not using a cutting board on the tile countertop. I have only responded in the most subtle ways to attempt to correct her habits, so far with only slight success. Fortunately for me, she has never heard of this forum.
Sometimes you hear it said that a sharp knife is a safer knife. My own experience tends to suggest otherwise. I have suffered a few cuts now and then, assuredly from a sharp knife, but an even worse one when actually sharpening a knife. That was a flat-ground, not particularly sharp angle Finnish hunting knife, but it certainly had an efficient edge. Does anyone here use any cut-resistant gloves for handling blades, especially when sharpening them? I notice my local woodworking store has a selection, right next to the Mora woodcarving knives. I know that logging supply places have special gloves but they might be vibration-dampening gloves, rather than cut resistant gloves. They also have chain-saw safety chaps, for those of you that play with such things.
I have never attempted to shave anything with a knive but my father did that all the time. By the way, the photo of the ax and knive is excellent.
Are you...
1. push cutting?
2. saw cutting?
1. paper or cardboard?
2. vegetables?
3. wood?
4. a variety of things?
There are different sharpenings for different uses. I keep my kitchen knives very sharp and a bit toothy. I love my tomatoes when in season and often sit down with a 'mater and a knife for a snack. I want my kitchen knives to thin cut a ripe tomato well. I've polished the edge on one and it didn't cut as well in a saw cut on a tomato. I do keep one big french knife sharpened to a greater angle and polished for chopping (push cut). I like my pocket knife fairly sharp for general (non-camping) use. I usually sharpen like a regular kitchen knife (fine, sharp edge), then put a small secondary bevel at a greater angle and polish a bit. This IS too fine an edge for general camping use.
All this means is just what I keep telling my better half. You need lots and lots of knives for different uses.
BlueTrain
26-08-2005, 14:23
What is the difference between push cutting and saw cutting?
It seems to me you can only do three things with a blade: slice, chop and stab.
fastbreak
26-08-2005, 14:42
I was surprised when Ray Mears (on Buschraft Series 1 DVD, I think) stated that a very sharp knife will stay sharper for longer than a blunter knife. But it might make sense, as long as various assumptions are correct e.g. the edge isn't so fine that it doesn't curl over at the mere sight of something to cut.
I wouldn't want to over interpret this but I suspect he just means that a less-than-sharp knife is already on the way to being blunt, while a truly sharp knife will take time to even get to the same stage as the less-than-sharp one. This is certainly a truism recognised by most woodcarvers.
On the general point of the thread. A sharp edge is essential to me because I use knives mostly for carving. A blunt knife is both hard work and dangerous for this.
If you are refering to the idea prevalent among some members that a Scandi, or "bushcraft" knife should have a razor sharp single bevel, then in most cases you are right, the edge won't last. The woodlore has an edge angle of about 30 degrees, so it will support a single bevel, most Scandi's are between 20 and 23 degrees and will collapse or chip without a secondary micro-bevel unless they are used on the softest wood.
But as has been stated before in this thread, there is a big difference between sharp and thin. Any blade with less than about 23 degrees on the primary grind does better with a secondary bevel in my experience. This might be a micro-bevel for general work, or a millimeter or so for carving very hard woods.
I know some people suggest that a secondary bevel makes fine carving impossible because the wood will split ahead of the knife. This is frankly not true. Almost all professional carvers I know use secondary bevels on their gouges and knives, they don't have the time or inclination to flat grind every hour or so. Whether or not your knife should have a secondary bevel (or how big and at what angleit should be) is not a fashion statement, it is a question of the primary grind angle combined with the use you wish to put it to.
I have seen people write on British Blades that they have carefully ground off the secondary bevel from Maihkel Eklund's blades, which is fine, but Maihkel's blades are ground at well under 20 degrees and without that 2ndry bevel, they will chip if they are used to cut anything harder than green softwoods or possibly clean lime.
If your blade dings as soon as you use it, then the grind angle is too acute for the edge you are using.
Have fun
Mike
Keith_Beef
26-08-2005, 15:18
Axes were frequently left outside at the woodpile. But those folks were all widows not looking too far into the future and, besides, they only used them to split wood, never to cut much of anything.
When I'm away at teh house in the country, the hatchet I use for splitting often stays out on the woodpile, but then the woodpile is under the three-sided shed I built about five years ago. Sure, it gets a few rust spots from condensation or dew, but it's never out in the rain, and I sharpen it twice per season.
However, mowing sythes were still common, even if they weren't used to cut large acreage. There were various sorts of blades, depending on what you wanted to cut. Now an interesting thing about sythe blades is how thin they are. They hold up fairly well, provided the user holds up his end and doesn't run the blade into the ground or attempt to slice stones, which grew very well around there. A significant point, though, is that the person using a sythe always carried a sharpening stone with him and he would run it over the blade a few times, oh, maybe as often once every half-hour and maybe more often. I suspect it was as much for the break from mowing as for sharpening.
Down in the south-west of France, a harvester would bind a wide cloth sash or belt round his waist to support his back ebfore going out into the field. The traditional method would be to fit one end of the long cloth into a drawer and jam it shut. Then hold the other end flat against his belly, and step away from the closet to pull the cloth tight. Now, turning round, he'd wind the cloth tightly round his middle until getting up to the closet, take out the end and tuck the free end round inside the sash.
Tucked into his sash, he'd carry three items with him to maintain the edge of the scythe:
a small stake anvil, called an "enclumette",
a cows horn filled with water, called a "coffin", sometines with a slim iron hook to hold it on the sash,
a slipstone inside the "coffin"
If he hit a stone, he'd pick it up to use as a hammer to beat the edge of the scythe on the stake anvil.
Sometimes you hear it said that a sharp knife is a safer knife. My own experience tends to suggest otherwise. I have suffered a few cuts now and then, assuredly from a sharp knife, but an even worse one when actually sharpening a knife.
Play with fire, you get burnt. Play with knives, you get cut. That's all there is to it. However careful you are, you'll get a few nicks. If you're careless, then I suppose a blunt knife will cut, whereas a sharp knife will take off a finger. But I maintain that an easy, controlled cut with a sharp knife is safer than a forced, uncontrolled cut with a blunt knife.
Does anyone here use any cut-resistant gloves for handling blades, especially when sharpening them? I notice my local woodworking store has a selection, right next to the Mora woodcarving knives. I know that logging supply places have special gloves but they might be vibration-dampening gloves, rather than cut resistant gloves. They also have chain-saw safety chaps, for those of you that play with such things.
I have a glove knitted from a special fibre that is braided stainless wire covered with kevlar. I never wear it. You can also find stainless chainmail gloves and aprons for meat and fish processing. I think that these are only usefull when working with chilled or frozen food (numb fingers don't feel that they're being cut) or you're working under pressure to produce quantity.
Woven, knitted or chainmail gloves should not be used with rotating blades, as they increase the danger of being snagged and drawn into the machinery. Better to lose a finger than your whole hand.
For the chainsaw, leather leg chaps are useful, though,. because the machine (chainsaw) is not fixed. It the moving chain touches you, you will no doubt let go, and the machine will fall away from your body, possible chewing up your chaps, but then onto your steel toe-capped boots (you've got them on, right?) and by that time, the motor has stopped.
Keith.
bloodline
26-08-2005, 15:33
When I first started out as a butcher we had the knives and cleavers ground once a fortnight on a wetstone then we kept the edges sharp with a steel one old boy always used to dampen the edge of his cleaver as he didnt like it too sharp not sure if it used to cut too far into the block for his liking or if the chops splintered so he liked to crush a little instead or was he just awkward :)
mojofilter
26-08-2005, 16:09
Down in the south-west of France, a harvester would bind a wide cloth sash or belt round his waist to support his back ebfore going out into the field. The traditional method would be to fit one end of the long cloth into a drawer and jam it shut. Then hold the other end flat against his belly, and step away from the closet to pull the cloth tight. Now, turning round, he'd wind the cloth tightly round his middle until getting up to the closet, take out the end and tuck the free end round inside the sash.
Tucked into his sash, he'd carry three items with him to maintain the edge of the scythe:
a small stake anvil, called an "enclumette",
a cows horn filled with water, called a "coffin", sometines with a slim iron hook Keithto hold it on the sash,
a slipstone inside the "coffin"
If he hit a stone, he'd pick it up to use as a hammer to beat the edge of the scythe on the stake anvil.
Keith.
Keith, your knowledge never ceases to amaze me! :)
BlueTrain
26-08-2005, 18:24
Now, these are some good replies. Nice details.
Returning first to axes, wood was still commonly used for heat and even more so, for cooking, relatively recently and still is in many places in the country. Where I lived in West Virginia, there was logging locally, though not on the scale of Washington and Oregon. One of the waste byproducts of a sawmill was so-called slab lumber, which were the rounded outside part of a log, usually with the bark still on, not otherwise used for anything. The mill would cut these to length and sell them for firewood. All you had to do was split them to suit yourself and your stove. If there was no local market for this wood or if there was a better market for the waste, no doubt that's where it would go.
Splitting the wood was a real chore, if you ask me. I did not see a splitting maul until perhaps 25 years ago, so they might relatively late on the scene. However, my father used an ordinary single-bit ax with a shortened handle of perhaps 18-20 inches long, more or less, that was very handy and could be used with one hand. He certainly kept his ax in the woodshed and I'm sure most people were more careful than the widows I referred to in my earlier post. However, those widows were assuredly old women living by themselves, most likely on very limited means and most likely, living like they had lived thirty years earlier.
When I was a boy (I'm 59 now), I often saw very old fashioned equipment around like hand turned grindstones, horse-drawn farm equipment, cross-cut saws, and the like. But all of it was old, even then, and anyone that could, used the latest stuff, even though lots of equipment now common may have still been restricted to industrial users. I am referring to things like chain saws. It isn't as though there was a transitional period between traditional equipment and modern equipment since, after all, we are always in transition.
Although there were small farms around where I lived, you would not call it a farming district and, anyway, I lived in a small town. It was more of a mining region. But even so, it was remarkable that there were those who managed to make a living on those tiny hill country farms. Some of them may have had other sources of income but they weren't hobby farms.
I recall my father sometimes using a hammer on a sythe blade but I don't think he would have used a rock picked up out in the field. But he didn't have one of those little stake anvils either. And nobody wore a sash.
I am still wondering about a push cut and a saw cut. But yes, I know about playing with fire and sharp knives. Did you ever try to light a gas stove, incorrectly?
TheViking
26-08-2005, 19:31
I take care of my knives so don't get dings. :) my 2 cents
Celt_Ginger
26-08-2005, 20:11
Hi. If it didn't matter if a knife was blunt or sharp, why do the manufatcurers bother to sharpen them? A knife or axe needs to be sharp. As sharp as you can make them. I trained as a Butcher, then moved into catering. A chef uses many different knives some thin bladed, some thick bladed, but all of them sharp. Sharpening a knife is not very difficult, or time consuming. Learning how to polish an edge on a sharpening steel is worthwile, (as well as a good party trick when it comes to carving the Christmas turkey) A sharp knife is less likely to slip off the item being worked. But that said, a skilled worker will produce good work, even with a blunt knife, but ask them if they liked using the blunt knife, and i would wager they would say "No"
What is the difference between push cutting and saw cutting?
It seems to me you can only do three things with a blade: slice, chop and stab.
A push cut, you just push against the work. A saw cut, you saw back and forth. Probably analogous to "slicing" and "chopping". An ax or a woodcarver push cuts. You slice (not chop) vegetables with a saw cut. If you leave an edge with little scratches, like just sharpened on a coarse or medium stone, it will have microscopic "saw teeth" when viewed with a jewelers loupe and will saw cut great. It will dull quickly with a push cut and need periodic aligning of the "teeth" with a knife steel on any cut. If you go to a finer stone and maybe a ceramic and polish the edge you will get a knife that will shave hair and be great for wood carving, will hold an edge for a longer time, but will not saw cut as well.
The General
27-08-2005, 02:47
Does sharpness matter? Of course! :D
Do you need a push shaving edge on a knife? Probably not, in fact it may be a lower performer depending on the intended medium to be cut.
However a nice polished edge is a great performer for most tasks and really is a nice thing to have. Is it worth sharpening a knife repeatedly to remove every last dink and chip? Well I don't, but I certainly don't just forget about this sort of thing as a small chip can microfracture and cause a much worse thing like a crack to form if simply left to become a stress point. I at least give the blade a good sharpen and thus greatly reduce the likelyhood that this will happen.
Lack of care for tools is not "bushcrafty" or in some way indicitive of a "real" user rather than a person who looks at loads of knives, collects them and never leaves the armchair. Its just plain lazyness! ;)
Joking aside, always look after your tools, keep the rust at bay on your carbon steel knives and keep them sharp!
A wipe with a bit of flitz and a bit of bog roll will keep the blade protected and rust will go away.
Question I would like to ask is... Rust, does it matter? Why do so many people think a rusty knife is not a problem? :confused:
Whats the point in carrying a blunt knife, a knife is meant to cut, if it can't do that its dead weight.
Rust is metal cancer, if you leave it it will destroy your knife, given enough time. Also, a momentary lack of concentration and a slip with a rusty knife......Ouch!! I'll let you imagine the consequences of that!
Care and maintenance of a knife shouldn't be a chore, it should take a few minutes to clean and oil after use, so long as you do it every time. Leave it and it will take a lot longer to sort your knife out, and that is when it does become a chore.
Give it a swipe with olive oil impregnated cotton wool after use, you can't go wrong!
Does sharpness matter? Of course! :D
I certainly don't just forget about this sort of thing as a small chip can microfracture and cause a much worse thing like a crack to form if simply left to become a stress point. I at least give the blade a good sharpen and thus greatly reduce the likelyhood that this will happen.
Which is the best reason to give your blade a bit of a polish, and the reason a properly sharpened knife holds an edge longer. If you go to Old Jimbos site he has some great stuff on giving your knife that first good sharpening and polish and how it then keeps that edge for so much longer. A jewelers loupe and a bit of playing around sharpening will teach you a lot.
http://www.oldjimbo.com/survival/valiant5.html
That link has a pic of an edge which hasn't been aligned or polished, and tells why it might blunt quicker. There are many other good sharpening atricles on the site, great stuff. The other articles are more hands on. In short, sharpen the whole edge on as big a stone (or sandpaper on a flat surface) as possible till you get a burr, or wire edge along the whole edge. Flip it over and do the other side the same way. Then polish with a fine stone, or sandpaper (also large). Finish with buffing compound. The point is to align and straighten the edge, then polish. Then you don't have the nasty spots to grab and break the edge (microscopicly).
http://www.oldjimbo.com/survival/cks.html
http://www.oldjimbo.com/survival/sharps.html
http://www.oldjimbo.com/survival/mora.html
jamesraykenney
01-09-2005, 20:49
Think of it this way:
A surgeon's scalpal will be sharpened to a very fine angle, a razors edge. Why? Because he needs it sharp to cut soft flesh, so massive edge retention is not necessary.
A general use knife, perhaps a SAK, a Schrade, or a Buck is sharpened at a medium angle. Not too fine, not too coarse. The edge needs a bit more wear resistance to aid in the blade cutting harder materials than the surgeons scalpal.
An axe (Gransfors Bruks anyone?) will be sharpened at a very low angle. Why? Because it is not needed for extremely fine work, and will be used on extremely hard, and edge degrading materials. The lower the angle, the lower the cutting resistance, but the higher the edge retention.
Keep in mind this also:
The angle is not so important as the CONSISTENCY of the angle.
Right?
Adam.
Do you HAVE a Gransfors Bruks??? I do, and it's edge is VERY fine...More than most knives!
jamesraykenney
01-09-2005, 20:51
I see what you are saying, but an edge doesn't need to be super fine to be sharp. A thick steep edge can still be made razor sharp, and be more durable. Obviously though, cutting ability is better with the fine edge, but there must be some form of comprimise between cutting efficiency and durability.
There is... It is called a CONVEX (http://home.nycap.rr.com/sosak/convex.htm) grind...
jamesraykenney
01-09-2005, 21:04
<snip>
I want my kitchen knives to thin cut a ripe tomato well. I've polished the edge on one and it didn't cut as well in a saw cut on a tomato.
<snip>
Try doing the polished edge again and then just ONE or TWO passes on a coarser stone.
I have heard that recommended as giving you a VERY good cut on things like that!
jamesraykenney
01-09-2005, 21:34
<snip>
I am still wondering about a push cut and a saw cut. But yes, I know about playing with fire and sharp knives. Did you ever try to light a gas stove, incorrectly?
You mean, where you turn the gas on too soon and next thing you know, you do not have any eyelashes???
No, of course not...:D
jamesraykenney
01-09-2005, 21:50
Rust is metal cancer, if you leave it it will destroy your knife, given enough time. Also, a momentary lack of concentration and a slip with a rusty knife......Ouch!! I'll let you imagine the consequences of that!
Care and maintenance of a knife shouldn't be a chore, it should take a few minutes to clean and oil after use, so long as you do it every time. Leave it and it will take a lot longer to sort your knife out, and that is when it does become a chore.
Give it a swipe with olive oil impregnated cotton wool after use, you can't go wrong!
What is the differance between getting cut with a rusty knife and one that is not???
I have never understood why it should matter...
I THINK this may come from the fact that a lot of rusty knives are also DIRTY, but I have a lot of things that are VERY clean that also have some rust on them(With an avrage humidity of over 50%, you are GOING to have rust!!!).
jamesraykenney
01-09-2005, 21:52
<snip>
Give it a swipe with olive oil impregnated cotton wool after use, you can't go wrong!
What is cotton wool??? I have heard the term a LOT, but have never heard anyone say just WHAT it is...
What is cotton wool??? I have heard the term a LOT, but have never heard anyone say just WHAT it is...
I think you Americans call it Absorbent Cotton.
OldJimbo
02-09-2005, 03:01
I believe that sharpness and a correct edge bevel are important - but that's a function of where I live and the damp conditions which we have over most of the year.
There are times when a person can easily smash a few sticks with a rock, then break a small rock and use the edge to scrape some tinder. Much of the time, though, it takes a blade with a decent bevel and a high level of sharpness to make fuzzies thin enough to burn properly. All of my axes, large clearing blades and smaller knives will easily whittle fuzzies for any conditions. I've done lots of experimenting with knives with steeper secondary bevels which I sharpened to easily slice paper or shave hair - but which wouldn't whittle fine enough fuzzies to get a fire going around here.
Probably the thing that's surprised me most since i learned to sharpen properly, is how my blades keep their edges. That applies to everything from axes to tiny knives. Partly this is due to even bevels and straight edges - but partly it's because I have to be careful with the blades, simply for safety.
BlueTrain
02-09-2005, 11:33
One of the reasons I like the British is because we speak the same language.
BlueTrain
02-09-2005, 11:49
A push cut, you just push against the work. A saw cut, you saw back and forth. Probably analogous to "slicing" and "chopping". An ax or a woodcarver push cuts. You slice (not chop) vegetables with a saw cut. If you leave an edge with little scratches, like just sharpened on a coarse or medium stone, it will have microscopic "saw teeth" when viewed with a jewelers loupe and will saw cut great. It will dull quickly with a push cut and need periodic aligning of the "teeth" with a knife steel on any cut. If you go to a finer stone and maybe a ceramic and polish the edge you will get a knife that will shave hair and be great for wood carving, will hold an edge for a longer time, but will not saw cut as well.
So that's the difference! Well, some of it went over my head. However, on the knives I use in the kitchen I never use more than a sharpening steel or whatever you call it. I don't cut anything especially hard in the kitchen. But I've already told you about my wife and her habits, which are another story. But we use different knives and so it doesn't matter.
I cannot claim to have ever examined any knife blade microscopically, only tested them on ordinary things like tomatoes, carrots, potatoes. By the way, I chop vegetables all the time--well, sometimes--with a French chef's knive using a rocking motion. But clearly the sharp knive is the one to use. All my kitchen knives and all but one outdoor utility knife are stainless.
Speaking of rust, on the other hand, objects that are constantly used but made of carbon steel usually take on a bright finish, depending on the steel, and sometimes more of a brown finish. Think of army gear that is constantly used under rough conditions and all the edges will take on a shine. For what it's worth, I've never seen a particularly rusty 65 year old bolt-action army rifle, which is not to say that many did not end up as junk. I guess what I'm trying to say is that if it is used, the rust won't become a problem.
jamesraykenney
03-09-2005, 02:56
I think you Americans call it Absorbent Cotton.
You mean like cotton balls are made out of???
Now I feel stupid...:o
Er, yes. The kind of thing used to clean baby's bottoms and ladies use it to remove make-up
What is the differance between getting cut with a rusty knife and one that is not???
I have never understood why it should matter...
I THINK this may come from the fact that a lot of rusty knives are also DIRTY, but I have a lot of things that are VERY clean that also have some rust on them(With an avrage humidity of over 50%, you are GOING to have rust!!!).
Whenever I cut myself as a kid and ended up in A&E they always asked if I'd cut myself on something rusty and if I'd had a tetanus injection. Then they always gave me a booster shot anyway.
For this reason I'd always thought rust was a carrier of tetanus. Well it's not. Animal urine and faeces are and the bacteria can be found in soil. If you cut yourself it allows the tetanus bacteria to enter your bloodstream. So if you work in a stable or cow shed and cut yourself on a rusty nail there is a high chance of infection, whereas if you cut yourself on a rusty knife that is otherwise clean then there is almost no chance of tetanus infection. You would also be just as likely to be infected by a non-rusty nail in the same stable.
However, you might still get an infected wound from a rusty blade the same as you might from any other wound. I heal up pretty quick and almost never get an infected wound but other people don't and need to make sure they disinfect any wounds immediately.
arctic hobo
03-09-2005, 21:07
Er, right, rust. Anyone considered stainless? Before this sounds like ultra-blasphemy, let me give you a few scenarios.
One, you are hiking/walking/climbing/cycling/whatever, and it starts raining. You're a way from home and soon all your kit is wet. Including your knife, which is sitting in your bag, forgotten because you're too busy both getting the tarp up and saving your sodden food, not to mention your clothes and sleeping bag.
Two, you live by the sea. You leave your knife on the windowsill/sideboard/anywhere. It perhaps isn't in its sheath.
Three, you're into watersports, and don't want to have the burden of your knife on your mind. Not to mention having to keep oil for it, and keep drying and oiling it.
All three of those could be got around, with good care of the knife and just remembering to do it. But in practical terms that doesn't always happen. There are stainless steels that hold an edge just as good as most carbon steels. I don't know the exact mechanics of it, nor the names of the steels, but even the standard stuff is more than satisfactory. All my knives are stainless :)
All mine are stainless too. I really can't be bothered to look after an Opinel or other non-stainless knife.