£300 plus knife ? ?

[0000]

Completely agree - and its this ' my opinion that trumps Facts ' thats been used elsewhere.

Assertion without any evidence.

Along with the typical 'argument from authority ' response , these are the bane of decent debate.

I'm not sure what you mean by 'argument from authority'. Isn't citing a source just this, or am I being pedantic? I personally don't believe that everything needs a chemical breakdown in order to be considered fact. For instance, if I told you that I can run a slow belt, with a coolant, and get a screaming micro bevel on a knife, all the while not even getting the blade warm or generating a single spark, would I need to cite a metallurgical study to back this up? I think it is within the realms of most peoples understanding without that. I feel like if you agree, and you should, that there is a spectrum of effect here from ramming a blade into a bench grinder to slowly hand sharpening, it would be perfectly acceptable to see that the method that I have described is far closer to the later than the former. Again, it isn't a method that I employ. I simply didn't want someone to read that post and later discount someones work because of it.

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[TeeDee]

I'm not sure what you mean by 'argument from authority'. Isn't citing a source just this, or am I being pedantic? I personally don't believe that everything needs a chemical breakdown in order to be considered fact. For instance, if I told you that I can run a slow belt, with a coolant, and get a screaming micro bevel on a knife, all the while not even getting the blade warm or generating a single spark, would I need to cite a metallurgical study to back this up? I think it is within the realms of most peoples understanding without that. I feel like if you agree, and you should, that there is a spectrum of effect here from ramming a blade into a bench grinder to slowly hand sharpening, it would be perfectly acceptable to see that the method that I have described is far closer to the later than the former. Again, it isn't a method that I employ. I simply didn't want someone to read that post and later discount someones work because of it.

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Sorry RuaridhHunter - my comment wasn't directed at you just in general , the 'Argument from Authority' tends to be dropped by people arguing a differing viewpoint who will cite their position or level of education on a topic as THE deciding factor in the strength of their argument/debate.

In reality what should stand is the merits of the differing opinion BY THE VERY POINTS THEMSELVES.

So as an example a PHd Maths Professor is arguing with an unqualified person on a Maths topic - they choose to cite their held position as the reason for WHY they are right ( and the other person wrong ) rather than allow that to be 'won' on the individual elements from the debate.

This approach only shuts down debate.

Argument from authority - Wikipedia

en.wikipedia.org

 

[0000]

Sorry RuaridhHunter - my comment wasn't directed at you just in general , the 'Argument from Authority' tends to be dropped by people arguing a differing viewpoint who will cite their position or level of education on a topic as THE deciding factor in the strength of their argument/debate.

In reality what should stand is the merits of the differing opinion BY THE VERY POINTS THEMSELVES.

So as an example a PHd Maths Professor is arguing with an unqualified person on a Maths topic - they choose to cite their held position as the reason for WHY they are right ( and the other person wrong ) rather than allow that to be 'won' on the individual elements from the debate.

This approach only shuts down debate.

Argument from authority - Wikipedia

en.wikipedia.org

Ah I see what you mean. I agree. I think that there can be some weird grey areas with regards to what constitutes authority in theory vs application. Not to discount either of course, but a fine wood worker or joiner doesn't necessarily need to cite the findings of a dendrology study in order to know how a wood behaves when he's working with it.



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[punkrockcaveman]

I think opinion holds weight if it is based on experience, specifically when there isn't a whole host of sources available to factually say a straight right or wrong.

Also I think humans are a bit flawed as we can go to the end of the earth in terms of perfection, when really, we should just get on with it and enjoy our time doing so.

 

[Billy-o]

It is an issue of plausibility not of correctness. Of course, after years of experience doing something, one will discover things that runs counter to received wisdom, common sense, textbook definitions and so forth. You can then tell people these things. But, without citation or evidence or theory, will anyone believe you, necessarily? One doesn't have to be surprised by that, just comfortable with it. Just think how many times some old duffer at work has said to you that, with their forty years of experience, they have discovered X, Y and Z to be the case, and proceed to spew out some patently bigoted nonsense and expect you to swallow it? Supplying proof and theory makes the difference between blindly accepting something as truth and understanding it as fact.

 

[Broch]

I think opinion holds weight if it is based on experience, specifically when there isn't a whole host of sources available to factually say a straight right or wrong.

Also I think humans are a bit flawed as we can go to the end of the earth in terms of perfection, when really, we should just get on with it and enjoy our time doing so.

True, I completely agree, but if it is opinion not fact it should be stated as such - so "in my experience" or "in my opinion" - doing it this way works because .... or words to that effect as opposed to "this is the way to do it". We are now debating debate of course

 

[0000]

It is an issue of plausibility not of correctness. Of course, after years of experience doing something, one will discover things that runs counter to received wisdom, common sense, textbook definitions and so forth. You can then tell people these things. But, without citation or evidence or theory, will anyone believe you, necessarily? One doesn't have to be surprised by that, just comfortable with it. Just think how many times some old duffer at work has said to you that, with their forty years of experience, they have discovered X, Y and Z to be the case, and proceed to spew out some patently bigoted nonsense and expect you to swallow it? Supplying proof and theory makes the difference between blindly accepting something as truth and understanding it as fact.

I agree with everything you say, but in the absence of a document of proof, I think that in this instance, describing something that is demonstrative that anyone with the correct tools can try, is good enough. I've seen the old duffer example a bunch of times in my life though so I see where you're coming from.

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[0000]

I think opinion holds weight if it is based on experience, specifically when there isn't a whole host of sources available to factually say a straight right or wrong.

Also I think humans are a bit flawed as we can go to the end of the earth in terms of perfection, when really, we should just get on with it and enjoy our time doing so.

Well said. I think as a professional maker I'm possibly too close to this emotionally

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[C_Claycomb]

If the question is, "does dry grinding alter the temper at a blade's cutting edge" I think a study with metallurgical testing would be of little use, and no practical value. You could get reams of data, but the best answer you could ever hope for would be "sometimes yes, sometimes no".

Here is an example of why you might not want to ask a very smart person from a university about something practical that they haven't had actual experience of:
I worked with a Stress Analyst, it was her first job having completed her PhD. She was very smart and knew a LOT more about finite element modelling than I do. We needed some thermal analysis done, using FE, of a thin metal sleeve slid down a motor stator bore. The stator was laminated, like a stack of pancakes, and the bore was not ground, meaning there were lots of little steps along the bore, one lam to the next. In theory, it was a clearance fit between sleeve and bore, you could push the sleeve down by hand (we hadn't made any at this point). Her analysis showed that the sleeve would get too hot, much too hot. The analysis assumed worst case gap between sleeve and bore, and assumed that any air gap was an infinite thermal resistance. Imagine a surface at 150C, now hold your finger a precise 0.1mm from the surface....do you think your finger might get burned? Not if someone with a PhD is right and any gap is an infinite thermal barrier.

A colleague worked with a university that managed to break 80% of some very expensive ceramic parts because they didn't take build and assembly tolerance into account when they had the parts made.

Arguments from authority can be difficult to avoid when time is short and there is a disparity in level of experience...most especially when the question is "why?". Your position could be based on experience gained over a decade, lots of little things that aggregate, but individually are not compelling to someone without that experience. They ask "why"...and you don't want to spend the time figuring out how to compress 10 years and dozens of learning experiences into a single argument that carries the weight of a full peer reviewed study.

This is a fun example about how hard it can be to answer some questions without being tempted to argue from authority.

 

[0000]

True, I completely agree, but if it is opinion not fact it should be stated as such - so "in my experience" or "in my opinion" - doing it this way works because .... or words to that effect as opposed to "this is the way to do it". We are now debating debate of course

I agree too but in this case, experience and opinion can also be fact. It is a fact that one can sharpen a blade on a slow belt and not generate any heat to speak of, thus, not to beat a dead horse here, not affecting a temper.

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[0000]

If the question is, "does dry grinding alter the temper at a blade's cutting edge" I think a study with metallurgical testing would be of little use, and no practical value. You could get reams of data, but the best answer you could ever hope for would be "sometimes yes, sometimes no".

Here is an example of why you might not want to ask a very smart person from a university about something practical that they haven't had actual experience of:
I worked with a Stress Analyst, it was her first job having completed her PhD. She was very smart and knew a LOT more about finite element modelling than I do. We needed some thermal analysis done, using FE, of a thin metal sleeve slid down a motor stator bore. The stator was laminated, like a stack of pancakes, and the bore was not ground, meaning there were lots of little steps along the bore, one lam to the next. In theory, it was a clearance fit between sleeve and bore, you could push the sleeve down by hand (we hadn't made any at this point). Her analysis showed that the sleeve would get too hot, much too hot. The analysis assumed worst case gap between sleeve and bore, and assumed that any air gap was an infinite thermal resistance. Imagine a surface at 150C, now hold your finger a precise 0.1mm from the surface....do you think your finger might get burned? Not if someone with a PhD is right and any gap is an infinite thermal barrier.

A colleague worked with a university that managed to break 80% of some very expensive ceramic parts because they didn't take build and assembly tolerance into account when they had the parts made.

Arguments from authority can be difficult to avoid when time is short and there is a disparity in level of experience...most especially when the question is "why?". Your position could be based on experience gained over a decade, lots of little things that aggregate, but individually are not compelling to someone without that experience. They ask "why"...and you don't want to spend the time figuring out how to compress 10 years and dozens of learning experiences into a single argument that carries the weight of a full peer reviewed study.

This is a fun example about how hard it can be to answer some questions without being tempted to argue from authority.

That was an interesting read. I'm not ashamed to admit that I have never heard of some of the things you were talking about though!

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[TLM]

We needed some thermal analysis done

LOL, FEM analysis of thermal problems are notoriously difficult because modelling of some things just do not correlate to anything. Been there done that and learned.

There is a way that grinding might affect the surface other than temperature, work hardening and softening. They are not common on typical knife steel states but not totally impossible. Detecting anything like that would require some serious study. Or failed heat treating.

 

[0000]

LOL, FEM analysis of thermal problems are notoriously difficult because modelling of some things just do not correlate to anything. Been there done that and learned.

There is a way that grinding might affect the surface other than temperature, work hardening and softening. They are not common on typical knife steel states but not totally impossible. Detecting anything like that would require some serious study. Or failed heat treating.

Interesting. Can steel that is already hardened be work hardened? I only have experience of work hardening with gold, silver and copper. It hadn't even crossed my mind with steel.

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[petrochemicals]

Well said. I couldn't agree more.

Ps. I can't believe you use a belt grinder. How barbaric. Do you also wear oven mitts and a blindfold when you use it?

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Also reads as i made this knife on a belt sander and want to charge you 300 quid. Ever thought of going into engines, im sure you could show rolls royce a thing or two ! Lol lol lol lol lol lol lol

 

[Nice65]

I thought most knife makers make knives on belt sanders?

I know Longstrider uses belts to sharpen, even if stropping, especially on the convex edges.

 

[TLM]

Work hardening is usually connected to ferrite phase that is not very common in large quantities in knives. It is present in perlite that apparently can be hardened a bit by working, again present in soft states only.

The other more pronounced appearance is in metastable austenite that changes to martensite when worked, actually used in heavy machinery as Hatfield steel that harden when worked on the surface but the rest stays softer and tough.

Hardened steel does normally not work harden at least that is my understnding but with some alloying and enough retained austenite I guess it might be possible.

 

[0000]

Also reads as i made this knife on a belt sander and want to charge you 300 quid. Ever thought of going into engines, im sure you could show rolls royce a thing or two ! Lol lol lol lol lol lol lol

Eh, no. No it doesn't. No I've never thought of "going into engines" but I have, funnily enough, done a fair bit of work for Rolls Woodgroup turbines. In any case we're talking about knives. I'm not sure if you're a teenage troll or just have an inability to stay on topic, but you're bringing nothing to this discussion.

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[0000]

I thought most knife makers make knives on belt sanders?

I know Longstrider uses belts to sharpen, even if stropping, especially on the convex edges.

Yes they do.

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[0000]

Work hardening is usually connected to ferrite phase that is not very common in large quantities in knives. It is present in perlite that apparently can be hardened a bit by working, again present in soft states only.

The other more pronounced appearance is in metastable austenite that changes to martensite when worked, actually used in heavy machinery as Hatfield steel that harden when worked on the surface but the rest stays softer and tough.

Hardened steel does normally not work harden at least that is my understnding but with some alloying and enough retained austenite I guess it might be possible.

Interesting! Thanks!

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[Woodywoodpacker]

I have a habit of getting wasted on a Friday night and buying stuff on the Internet that I shouldn't really buy and can't really afford. I have a few 400 quid plus knives that I use regularly. An Alan Wood Bushcraft knife Scandi grind. Beautiful to use and carve with. I also have an Origin bushcrafter convex grind which I beat the living daylights out of on a regular basis. It just laughs at me and asks for more. My original bushcraft knife I gifted to a friend who was just starting out. I will never forget the look on his face when he used it for the first time as I gave it to him shaving sharp. I have a few SWC woodlore knives though that sit in a cupboard and aren't used. The oak handled one and the older reclaimed handled one. Sometimes though after a few beers I dare myself to go into the garden and start battoning wood with them then I could use them. Luckily though I would never get a knife out after the drink.