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Questions about: Prelaminated, forge-welded, HT and expectations on quality

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DanielC

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I guess one would have to then define the parameters of good, better and best which would simply be opinion and why some like this or dont like that.

As far as the end product is concerned, it should be extremely hard if not impossible to tell where the billet was created initially if it was forged. The process itself whether its mine or someone elses is the behind-the-scenes methodology to get the user the knife. If in the end the core steel is the core steel, the rest will more or less be inconcequential, as we are both forging out a billet. Consistency in core alignment should be very important to every maker and I detest and would not sell a blade that had cladding meet the edge. I havent had that problem in a long time though. Other than core alignment I'm not sure which part of the process can be measured in such a way. For certain steel combinations, my forge is set to a specific temp and the steel is at heat for a specific time before its met with the power hammer. If in making the same type over and over especially, the consistency is as measurable as a consistent HT for example. If what you are referring to are maybe defects in the billet, rest assured, I and most makers I know making high end cutlery wouldnt even try to give away a knife made from a billet that displays problems like delams. I once spent 2 years chasing my tail trying to sort out problems with flux inclusions at the weld line. I like to pre-weld several kilo in billets at a time and set aside for forge work. I didnt like the possibility of one kf those billets having trapped flux between the layers. After a lot of knives I deemed failure, I finally switched my process as began my road into what is called Dry Welding, which doesnt use a fluxing agent.

To give a little background in that, back in 2014, I was floored by Maxims video in Kiyoshi Katos shop. I immediately started training his process un my shop. It began my journey with traditional sanmai. It was this very traditional approach that stuck with me for a long time. However, at the time I still had a westerner interpretation of it all, and it seems Kato's weld lines often contain the same flux inclusions I deemed as instant fail. Wabi-sabi wasnt part of my vocab. I eventually modified his process with dry welding and ceased having issues. It was after that I had discovered he has the same issues but still sells them. It's not so noticeable when you stone polish. Etch it like most westerners do and its plainly obvious and to me was always an eyesore.

Not to get too distracted, but where you will see real evidence of using pre-lam is with those that are limited to stock removal. A maker was recently brought up in a thread who has no affiliation here that his very attractive knives only tapered towards the tip. It tapered only there because that is where his grind began. That maker who I know, doesnt really forge and buys a lot of pre-laminated billets and grinds a blade from them. This approach ofcourse means no distal taper. It also means the jacket seperation line rides much higher at the tip.

Trying not to get convoluted, but I'm sanding wood right now :)
 

ModRQC

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Thanks for the real insight into this process, very illuminating. I think my questions have been answered thoroughly by all makers who took their time to share here.

Much appreciated @Kippington @HSC /// Knives @RDalman @DanielC. Invaluable insight, so much more than I bargained for posting this thread. Be well all!
 

chefcomesback

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Prelaminated steel yields its self more towards stock removal, there are lots of that stuff sold in 3mm range and you can tell easily which knives are made with it and they are stock removal .
It’s easier to forge the entire geometry by making your own billet . Unless you are keeping the billet in welding temperatures for long time you are not losing significant amount of carbon , for example it takes roughly 1-2 heat in welding temps to get the billet consolidated and 3 more in lower heat to forge the entire geometry/ distal taper / tang etc
 

Kippington

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I've got no arguments on specific examples of in-house work being of higher quality than specific examples of factory prelam. I was talking more generally, but I think most of you got the gist of it.

It's kind of why I brought up car engines. Here is a picture of the Koenigsegg engine room, vs the Toyota engine factory. I know which one I would prefer.


Keep in mind smaller makers/manufacturers these days can still use machines that border to the "factory" image supplied... There are smaller scale rolling mills/presses etc that can be used in smaller settings as well.
Bob Kramer has some pretty nifty machines. Totally not jealous...

 

RDalman

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I've got no arguments on specific examples of in-house work being of higher quality than specific examples of factory prelam. I was talking more generally, but I think most of you got the gist of it.

It's kind of why I brought up car engines. Here is a picture of the Koenigsegg engine room, vs the Toyota engine factory. I know which one I would prefer.



Bob Kramer has some pretty nifty machines. Totally not jealous...

Absolutely. I was considering if I should put extra statements in my posts that I myself don't put any judgement or value either way. One should stick with his passion 👌
 

ModRQC

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I appreciated all inputs. To me there's no party, but an exercise of relativizing. What I've taken out of all of makers input is that it doesn't change anything - ultimately it will still boil down to who does HT right, and who has that knack for creating a good knife.
 

billyO

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both of them delaminated on forging down tangs.
Please don't read this as an attack on your skills as a blacksmith (I will never know as much as you know about what you know), but rather a clarification for folks in the future who have little to no knowledge of the forging process.

Delamination during forging can come from a problem in the billet itself, or a problem during forging. Different steels will move differently and forge at different temps so without seeing what you did on the above-mentioned knives, and assuming that the billet had no flaws, it's possible that you were forging too cold for the steels involved, and created a shear force between the layers opening a de-lamination. It's not too hard to do this when forging down a tang, especially if you are using a press. There's not much mass to retain forging heat in the tang at blade thickness, and presses are known to suck heat out of a piece a lot faster than hammer and anvil.

I was going to post a couple other references/studies about how fast carbon migration occurs during forging , but not sure if that's relevant anymore.
 

Beau Nidle

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Please don't read this as an attack on your skills as a blacksmith (I will never know as much as you know about what you know), but rather a clarification for folks in the future who have little to no knowledge of the forging process.

Delamination during forging can come from a problem in the billet itself, or a problem during forging. Different steels will move differently and forge at different temps so without seeing what you did on the above-mentioned knives, and assuming that the billet had no flaws, it's possible that you were forging too cold for the steels involved, and created a shear force between the layers opening a de-lamination. It's not too hard to do this when forging down a tang, especially if you are using a press. There's not much mass to retain forging heat in the tang at blade thickness, and presses are known to suck heat out of a piece a lot faster than hammer and anvil.

I was going to post a couple other references/studies about how fast carbon migration occurs during forging , but not sure if that's relevant anymore.
No offense taken. The first time it happened I assumed that it was my fault too. After forging at different temps, both by hand and on my small power hammer, I've experienced the same issues. I would like to try the same material in a larger thickness and see if that had an impact. When making san mai I always leave it quite a bit thicker than the prelam billets if I plan on forging it to shape.
 

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