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Author Topic: Thoughts on Knife Talk DVD volume I  (Read 11899 times)
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Ed Fowler
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« on: November 28, 2006, 09:29:49 AM »

As the new DVD gets into circulation, thoughts and questions are most welcome.

The first question that I wish to address concerns quenching the blade in Texaco Type A oil.
As explained in the DVD, the oil is preheated to 165 degrees.

When I quench the blade it appears that I am heating the spine with my torch. I am not heating the blade, but using the torch to burn off the fumes (smoke) in order that they don't fill the shop. Usually I have a filter that takes the fumes out of the air, it makes noise that would have interfered with our conversation, therfore I burned the fumes.

Actually burning the fumes is a beter solution that the filter, best is to burn them off as the form and use the filter also. I do not believe the fumes are harmful to the maker or I would not be alive today, but it does no harm preventing breathing them into our lungs.

Any of those who watch the DVD and have comments or questions, please post them here.
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Ed Fowler
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« Reply #16 on: October 06, 2008, 06:49:53 PM »

Kevin: I admire your testing: especially the use of a reference blade, using a constant reference blade provides a comparison that cannot be achieved in any other way.

I have never found my Texaco Type A to draw in moisture, I was told it is pure heavy weight mineral oil and was originally sold here to Vets to tube horses and lubricate problem births come calving time.
Now they buy from the vet supply outfits, it still works, but does not seem consistent. (?)

One system you wrote about was varying quench oil temps. I have also read about varying tempering temperatures. With the steel we use Rex does not see any benefit and I have not been able to identify any significant differences because of it.

I feel that most of these practices have a basis in history, the problem is finding what that basis is can be almost impossible. I was reading an older book and found where they used varying temperatures to achieve a certain quality in the steel they were using. I wrote a note about the steel and purpose and immediately lost it. I do remember that it would not benefit the 52100 steel we are using. I have reviewed the books and the facts still evade me. If you or any readers have come across this information I would sincerely appreciate it if you would let me know the source.

Many times valuable information can be had from fiction (Wellman's book The Iron Mistress) " I hardened her 7 times" I wonder where or who he obtained that information? Also: old references can be of value. I have a book written in the 30's about multiple quench and 5160 in a footnote they stated it was the finest grained steel they had ever seen. A few years later US steel pattened a multiple quench process. New Holland for a time advertised their cutter blades as having been through the fire twice - I called and asked what they meant, but could not get any answers.

When we see a demonstration that looks exceptionally impressive (too good to be true) we can learn by seeking to duplicate their theatrics.
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« Reply #17 on: October 08, 2008, 06:34:10 PM »

Hey there buddy, how ya doin?
 I just finished watching both your dvd's and just let me tall ya. WOW!! These are full of great info. I could probly watch these 1000 times or more and still not get all the info from them. You have spent numerous hours in forging, testing, and figuring all this out, and I thank you for sharing it all with us. After I have a couple hours to process all this new info I'm sure I will have some questions for ya. Thanks, Shane
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Phil Dwyer
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« Reply #18 on: December 26, 2009, 08:13:56 PM »

The side hit by the hammer receives a more concentrated force than the side on the anvil. If you doubt this just take a board and lay it in sand and hit one side with a hammer, you will see the dent in the board, but the force will be distributed through out the side in the sand. When I get my steel from Rex, it is in 3 x 3" x 14". I mark the bar that I weld the billet on randomly deciding which side will be the future cutting edge of blades and the opposite side the spine. All future hammer blows will be to the future cutting edge and sides of the blade.
Rex can see the difference in the microstructure of steel before any heat treating, when I send him unheatreated steel for lab work he knows which is the intended edge through photomicrographs.


Hey Ed,

Dang, I guess I wasn't paying good enough attention when watching your DVD. Of the four sides, I had thought you said you've learned to never hit on the edge. Was I ever worried about that. I just couldn't see how I was going to beat the flaring out beveled edge back into the forming blade so as to line up flush with the ricasso without being able to hit on it. To make matters worse, later in the DVD demo I saw you hitting down on the edge and I was really baffled (thinking you had said not too). This clears my confusion up. I like your explanation of the board on sand too. That's about as perfect a picture analogy as you could come up with.

That being said, I'm still trying to wrap my mind around why hitting down on the spine would be detrimental, whereas doing so on the edge isn't. My conceptualizing goes something like this....



The layers of colored clay represent a side of a blade being forged that got "hit" twice on the spine and sending vertical ripples perpendicular to the forming blades length. These blows to the spine might perhaps initiate "shadows" across the "linear" grain structure of the blade's length and might suggest the future possibilities of stress risers being a bit more probable. Would the reason this might not be so much of an issue when done on the blade's edge be because the edge will be forged so much more thoroughly as the bevels are set?

Thanks much, Phil
« Last Edit: December 26, 2009, 08:18:16 PM by Farmer Phil » Logged

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Ed Fowler
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« Reply #19 on: December 26, 2009, 08:41:16 PM »

This is an excellent question:

It is not so much that hitting the spine with a hammer is detrimental as that hammering the spine is a waste of energy. If we accept the premise that forging can be beneficial to the finished product, then the more forging energy we direct to what will become the cutting edge, the better the edge can be. The cutting edge that will do the work is where we want to put as much devotion to as possible, all the spine has to do is be strong, tough, support the edge and not chip with hit with a hammer or rock to beat the edge into what needs cut. That is easy to achieve, ultimate cut can use all we can give it.

I sent Rex some samples about 1 1/2 x 1 x 2 inch. They had been forged hitting one edge only and the sides. By checking them out though his microscope he could tell which was intended to be the edge and which was intended to be the spine. The intended spine had grain that was not as refined as the intended cutting edge, due to the less hammer work on the spine.

No single event is THE event. They all come together a little bit at a time to contribute to the final product.

Like you said the cutting edge will receive more blows than two, we use flat dies and start with large stock to allow us to work our rate of reduction by forging through the use of as many hammer blows and thermal cycles as possible.

Continue to work the cutting edge of your clay and the sides and the edge and the sides until you have it forged into a blade shape and you will see the spine edge will remain much the same while the 4 layers above the spine blend in to a higher degree over time. Use a light hammer and watch it happen the more hits the finer the blend.

Good idea with the clay!
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« Reply #20 on: December 08, 2011, 05:59:02 AM »

I watched 52100 Wootz last night for the first time and dreamt of steel all night long!!  I cannot wait to get to the Willow Bow and experience this for myself.

I have a question about L6.  Ed, you mentioned in the film that L6 seemed to be a good steel, also.  It seems that L6 is popular among stock removal knifemakers.  What about the forging of L6?  Have you worked with it yet/much?  Would you still look for a 95 to 1 reduction of it in forging?  and if so, where would you get L6 that thick?! 

Another question about your hammers.  You used 2 different power hammers that looked to be about the same size.  Why did you use one and then the other?  Different dies? or different weights?

btw:  I thought you and Rex did a bang-up job!! 

Thanks
Chuck
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Ed Fowler
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« Reply #21 on: December 08, 2011, 10:56:44 PM »

AT one time I thought a lot of L-6, but it is more a steel for stock removal and does not come in sizes that will permit us to push it to its full performance potential.

I have two 50 Lb. Little Giant hammers in my shop, named Gray and Green they each have their special function.
Grey has drawing dies in her and they are used to forge the tangs of our blades easily,, the than does not have much work to do, all it needs is to be strong and that is easily accomplished.
Green has very slightly rounded dies and allows us to develop the blade steel to its highest potential through the necessity of many hammer blows to shape the blade.

Thank you for your compliment on our DVD, Rex, Jeremy and I put a lot of time into it and all the information is valid. Jeremy edited over 20 hours of tape down to what you watched, he did a great job of keeping all the information in condensed form.

I am very pleased you liked it.
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