Is there an art to sharpening

I've almost completely converted to water stones for tool sharpening using two combination stones .. 250/1000 and 1000/6000 grit. These are the cheapy "King" brand.

I also use a small DMT diamond hone, bought for router cutters, but useful for odd sharpenings.

I'm surprised about the chrome idea. Surely these blades are stainless steel, and that's half the problem.
 
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My wife once asked the butcher how best to sharpen knives and he suggested a kitchen knife sharpener [the kind with a number of hardened metal wheels]. I've used one of those for many years now - very quick and effective.

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They wear the blade away. We have an old kitchen knife that my father sharpened on one for many years but there now is less than half the original blade left!
 
You can sharpen with all sorts of abrasives. Some ideas I've seen include .. wet and dry sandpaper (aka "Scary Sharp"), metal polish on glass, leather strop with compound as mentioned above.

The problem with knifes (I find) is the curved and springy blade makes it hard to keep a consistent angle and pressure on the stone.
 
Got fed up trying to keep an edge on stainless steel knives. Just bought a SUPERKNIFE from Aladdins Cave. Uses an ordinary craft knife blade and you can replace it in seconds- far quicker than all that sharpening!

Safe sailing

Sparkie
 
Thread drift ... but look for Irwin blades instead of Stanley. They are direct replacements but I find they hold an edge better and are made slightly flexible so are less prone to chipping and snapping. Well worth the extra few pence.
 
Quote "I'm surprised about the chrome idea. Surely these blades are stainless steel, and that's half the problem."

I agree, I have yet to find any stainless tool that will take and hold as good an edge as properly hardened and tempered high carbon steel. Most kitchen knives now are stainless for good reasons of convenience, but cheap ones are generally pretty hopeless in terms of sharpness or rely on a serrated edge to produce a sawing action. I do have a very short bladed stainless kitchen knife which is pretty good, but in terms of ultimate sharpness cannot compare to a French Opinel folding knife with a carbon steel blade. The test is to hold up a sheet of writing paper and slice it from end to end in one stroke without any tearing. The Opinel will do it reliably, the best stainless knife I have will not.
 
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As for running your finger over the blade, well, I am still sporting a nice deep cut on the top of my thumb after trying to see if my plane blade was sharp enough to take a bit off the back door as I get fed up in winter having to kick it!

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The best (and safest) way to check the sharpness of a blade is to use the edge as a mirror, looking at the reflection of a strong light. Sharp blades will show no reflection; blunt blades will show a line of light along the edge. Shows up nicks in the blade, as well.
 
Scary Sharp is right! (Google search if you haven't heard of it)

Using 800 then 1200 grade wet'n'dry oiled to a sheet of glass as a sharpening stone lets a clutz like me get PROPER edges on chisels & plane irons. Easily good enough to shave with, and almost un-noticeable if you cut yourself (until you see the blood /forums/images/graemlins/crazy.gif ).

It's harder to do with knives, because you have to maintain the angle around the curve of the blade, but still works the best for me.

Is it just me, or do others become slightly obsessed with getting a perfect, super-sharp edge ? /forums/images/graemlins/blush.gif

I use a very fine diamond whet-stone (with water) for getting the right bevel, and for non-obsessive sharpening.

Andy
 
A perfect, super-sharp edge can be the difference between cutting the rope taught in the air or having to saw through it laid on the deck thus leaving marks on the pretty gel coat.

I would love my dear one's gerber knife that she got as a thoughtful birthday pressie a few years back, it is a wonderful knife, but I could not live without the other stuff on my swiss army knife.

My old gutting knife, I don't know where it is now, was almost a personal knife as it had been ground down after many years use, like a plasterers float or hairdressers scissors, you do not share gutting knives on trawlers. I would sharpen that by putting sand on the gutting board and grinding it, though it had to be done every hour or so it gave it a razor type edge. When gutting for a living you need to be fast and that required a sharp edge.

But it never had a nice edge, just sharp and not for very long; it did work hard though!

The reason I started this thread was to find out why I could never maintain a sharp edge and maybe you're right, keeping a fairly sharp edge is probably easier than trying to hold on to a razor sharp edge.

Been interesting though.
 
At the rik of starting a war I agree with most that already been said but Vitronox blades are not as good as Gerber or Leatherman!

Another factor is that I believe blades are tempered unevenly harder and more brittle at the edge and softer but more ductile in the area behind the edge to give the blade more robustness.

Consequence is that you will never get as good an edge as the knife wears down as when new.
 
Agreed.
I go through a steel about every nine months or so sharpening kitchen SS knives. The memsahib has an uncanny knack of blunting a knife by looking at it.
But my french carbon steel gutting knife on the boat hardly needs touching. Its maybe a combination of hardness and the thin blade.
I am old enough to have used a scythe with a carbon steel blade a yard long, sharpened with a stone hung on a bit of string round the waist. It would go through anything.
 
Problem with knife blades is that the steel used to make them is usually non corrosive (stainless) and thus doesn`t hold an edge for long unlike a chistle which is usually laminated steel etc
 
Good stainless steel knife blades are made of one of the 400 series stainless steels which are martinsitic and can be heat treated to produce exceptionally hard blades which will hold an edge. Cheapo stainless blades are made from the 300 series Stainless steels and are austenitic and will not hold an edge.

Laminated chisels are hard to come by these days although I believe Sorby still do a "hardback" range. Japanese chisels are folded and forged so are one material wheras "hardback" chisels had an exceptionally hard back laminated (forged) onto a lower grade steel which provided the support.

B&Q type chisels are not much use.
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Austenitic stainless will work harden, as most of us discover when drilling with a blunt drill. So if compressed, perhaps by a roller or hammer, the edge should harden. Problem is, the knife blade will almost certainly distort.

I agree with Cliff, the correct material is the magnetic martinistic stainless.

Philip
 
I bought some quite pricey kitchen knives, actually about 10 years ago and they are still my new knives as they have lasted so well. Kitchen Devil I think, the French chef's was about £30 I think.

First off, they are not shiny, yet not brushed. If I leave them wet in the drainer for too long they can get slight rust staining on the back, the flat bit of metal opposite the sharp edge. It just wipes off, but tells me it is either not stainless or a low grade stainless, which from what I have learnt from this thread is designed to allow it to stay so sharp.

I sharpen them on my wheel type sharpener, which I have also realised I was not using properly, you are supposed to tilt the knife in each direction to get a 30° angle.

On the other hand my victorinox is shiny stainless and has been used under sea water fairly regularly, washed in fresh, but never a sign of rust, probably not the best material but a good compromise. My crews Gerber is like the kitchen knives, duller, almost grey.

This is a guess, but from which of my knives are good and which are just ok.

I would like to think by buying a brand you would be safe, but when shopping for the gerber I looked at the Musto knives and really was not impressed, though they were also a 6th of the price.

It is not easy.

as an aside, I wish victorinox would set up a haute couture type service, you can choose from a set of blades and make up a knife that suits you and allow to lose those that no-one ever knows the purpose of /forums/images/graemlins/grin.gif
 
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