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Thermite forged and etched...


Kerrystagmer

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My friend Rick Janney forged out a bar from a railroad thermite sprue (vent technically), formed a blade, polished and etched in vinegar.

 

The white stripe appears to actually be a difference in the material near the center of the vent. Often on these bars there are cracks or faults along that line.

 

ricketch1a.JPG

 

ricketch2a.JPG

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I'm thinking the alloy is actually different at that line. Remember these are from vents NOT sprues really. There is a big difference as a sprue is basicly pure clean metal on its way TO the mold and vents are residue and crap mixed with metal on the way OUT of the mold. It would also be where the incoming metal is coolest before the bulk of the reaction is occuring.

 

The line area is where the vent has a void in the center that slowly tapers off to solid. Maybe its just heated differently as it would be where the steel is gassing off from the pour, maybe its different in material.

 

For the future to get a even pattern I'd just grind the area away before forging by splitting the material down the center.

 

BTW to give you some compairison to bulldozer plates at temperature when forging, the bulldozer plates(Cat calls it DH-2) work about like any other steel. This stuff is awful to forge. The 200 lb hammer just bounces off it. This size blade (palm sized)takes 2-3 hours just to rough forge, not forging the edges.

 

Does look good though! The guys I filmed saved all the material they ran and dropped off a bucket of this stuff. I gave Christopher Price a chunk, I cant wait to hear what he thinks of pounding on it!

 

BTW this was a 1 and a half day etch in vinegar, no ferric.

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I'm thinking the alloy is actually different at that line. Remember these are from vents NOT sprues really. There is a big difference as a sprue is basicly pure clean metal on its way TO the mold and vents are residue and crap mixed with metal on the way OUT of the mold. It would also be where the incoming metal is coolest before the bulk of the reaction is occuring.

 

The line area is where the vent has a void in the center that slowly tapers off to solid. Maybe its just heated differently as it would be where the steel is gassing off from the pour, maybe its different in material.

 

For the future to get a even pattern I'd just grind the area away before forging by splitting the material down the center.

 

BTW to give you some compairison to bulldozer plates at temperature when forging, the bulldozer plates(Cat calls it DH-2) work about like any other steel. This stuff is awful to forge. The 200 lb hammer just bounces off it. This size blade (palm sized)takes 2-3 hours just to rough forge, not forging the edges.

 

Does look good though! The guys I filmed saved all the material they ran and dropped off a bucket of this stuff. I gave Christopher Price a chunk, I cant wait to hear what he thinks of pounding on it!

 

BTW this was a 1 and a half day etch in vinegar, no ferric.

Hey Kerry....Think I should re etch that blade I did in vinegar???

That looks way cool.

 

 

Larry

RR4.bmp

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I'm sure this chunk is going to be my personal nemesis, the steel I work on to "grow stronger" in the ways of the hammer.

 

Actually, I may save it for a time when I have access to a press... though, I wonder if the hammering process has anything to do with refining that pattern. From what Ric's told me, that has as much to do with the look of wootz as its chemistry and creation process.

The Tidewater Forge

Christopher Price, Bladesmith

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I was under impression that heat cycling was important for the pattern. Trust me, when you make something from this , heat cycling will occure!

 

That is Rick's third knife in this stuff and he has 2 more on the way. I think Larry is starting on his second BUT we have a sword sized bar he forged out sitting in the shop. My brother forged and ground a very nice long thick dagger, but the center was cracked and didnt show till in grinding. A real shame...

 

Sooner or later we will get sick of it and go back to something easy like D-2 :blink:

Edited by Kerrystagmer
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Man...I forged and ground a killer dagger blade and got all the way done the grinding just to walk outside and notice a crack all the way through :angry:

 

I will be grinding on a piece that Nowicki forged soon. It will be a shortsword of some sort. I might go back and attack another dagger before the sword. I love the material. Its hard to forge and even harder to grind. A great challenge and if you do it right it turns out beautiful !

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COme on guys, KATANA TIME:D. Add another sword o the superkatana craze:D.

Let not the swords of good and free men be reforged into plowshares, but may they rest in a place of honor; ready, well oiled and God willing unused. For if the price of peace becomes licking the boots of tyrants, then "To Arms!" I say, and may the fortunes of war smile upon patriots

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I can hear your power hammers screaming for mercy in the background:D.

Let not the swords of good and free men be reforged into plowshares, but may they rest in a place of honor; ready, well oiled and God willing unused. For if the price of peace becomes licking the boots of tyrants, then "To Arms!" I say, and may the fortunes of war smile upon patriots

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  • 8 years later...

Are all thermite welding vents good for blades? I picked up a few and although the one I'm working on is hard to forge it doesn't throw sparks like high carbon steel, is each one vastly different? Also what do you quench into?

Generally speaking, they are not good for knives in terms of mechanical properties, but great for a visual; i.e. pretty but not functional. I can't imagine this material holding a decent edge.

 

Thermite is often measured out in general quantities and thus pretty random from one batch to another, but I would guess that US rail companies would required a fairly tight control over the ratio. Any carbon that gets in thermite is a "contamination". The RR uses it join track together, so it is being "contaminated" by 1070-ish material, which is good for blades. The big thing about thermite being bad is all the aluminum that ends up in it (not all of it will be converted to alumina, and some that is will remain in as trapped slag). What is shown as white area in the etch above is from alloy segregation. A vent, like a sprue, will have the outsides freeze first with the center freezing last. The first part to freeze will have a different chemistry than the last to freeze. In the steel casting world we worry most about "under-riser segregation" when talking about this effect. The cracking that Kerry mentions seeing is actually from voids from the vent "feeding the casting", as well as from this alloy segregation.

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After searching the tracks some more I found one that looked much older and the spark test resulted in a mich better spark pattern, I think il save it for a special project while practicing with the many others I found. Also with the amount of welding going on in my area if anyone wants one to try out I could ship some out as long as the shipping is covered plus a little

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  • 2 weeks later...

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