Flint strikers...

Pretty good write up, thanks for sharing. Glosses over a lot and has a few errors yet pretty good overall.
 
5160 (spring steel) hardened to course pearlite seems to work well. I've always wondered how aluminum oxide would work if I could get a chunk large enough. Works well on the belt grinder. I like the striker designs.
 
ED: If you could get aluminum as hard as knife-hard steel, it might work just fine. Aluminum sparks?
 
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Aluminum shouldn't work because what causes sparks isn't friction it is a chemical reaction of iron. Iron is pyrophoric which is any material that spontaneously combustes below 130 degrees Fahrenheit. What you are doing is shaving off a small piece of iron which then combustes due to contact with oxygen. I have no degree in chemistry and could be 200% wrong?
 
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STAINLESS90 said:
Aluminum shouldn't work because what causes sparks isn't friction it is a chemical reaction of iron. Iron is pyrophoric which is any material that spontaneously combustes below 130 degrees Fahrenheit. What you are doing is shaving off a small piece of iron which then combustes due to contact with oxygen. I have no degree in chemistry and could be 200% wrong?
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I did not realize that the combustion temperature was that low! Does the carbon content just help the iron hold the spark longer?
 
Bo T said:
I did not realize that the combustion temperature was that low! Does the carbon content just help the iron hold the spark longer?
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I think it has to do with making the steel hard enough to shave a piece off of.
http://survivaltopics.com/flint-and-steel-what-causes-the-sparks/
Here is a link to the technical explanation of how the flint and steel process works.

EDIT: It looks like the carbon is added for that exact reason, if it is too soft you can't get a small piece to flake off. The carbon makes the steel more brittle.
 
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Bo T said:
Aluminum oxide (ruby, sapphire) in place of the flint.
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Oh. To strike the steel. Are you going to give it a try?

"The sharp edge of the flint is used to strike the fire steel at an acute angle. With practice, small pieces of steel are shaved off the fire steel. The friction of shaving the steel off the fire steel and the pyrophoricity of the steel heats the pieces to a molten state."
 
I've never checked, but there might be a piece of corundum large enough and cheap enough to give it a try. But it could be too brittle.
 
Stainless90 is half correct about the the combustion. Both the friction AND the small size are needed.

Think about sanding, filing, sharpening, etc by hand - do the tiny pieces of steel spontaneously combust? Nope. Now do it at high speed. Yup, glowing sparks. Thus clearly both are required.

Smaller objects have greater surface area thus are exposed to more oxygen. Much like using small sticks for starting a fire, rather than large logs. Much, much easier!! The friction kicks up the temp of those tiny pieces of iron which increases Brownian motion, thus accelerating the reaction (oxidizing aka rusting) until the iron burns. Heat a 3' cube of iron to 130°F, does it burn? Nope. So it is more than just the heat, it is the size as well.

Stainless90 is completely correct that the ONLY thing the carbon does is make the steel hard/brittle so that pieces of iron small enough to spontaneously combust can be broken off. There is a sweet spot between 57-63HRC, with 59-60HRC being optimal, for making sparks with rocks and steel.

Obviously if the steel is harder than the rock, all we get is rock dust - no sparks. Note the sparks that come off of 57-58HRC steel tend to be fewer, weaker, duller and shorter lived. The sparks thrown by 59-63HRC steel tend to be more abundant, brighter, larger, longer lived. I am 6'2" and can throw sparks off of 59-63HRC steel with a rock from armpit high and they are still hot enough after falling all the way to the ground to make people with sandals or bare feet dance. Yup, flint (the rock) and steel - not a ferrocerium rod, though those will do that too.
 
duxdawg said:
Stainless90 is completely correct that the ONLY thing the carbon does is make the steel hard/brittle so that pieces of iron small enough to spontaneously combust can be broken off.
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I don't think this is quite correct. The carbon content of the steel also changes how it sparks, regardless of its heat treatment. High carbon steel throws more and brighter sparks, with numerous branches like a sparkler, compared to mild steel. This is the basis of the "spark test" to figure out what kind of steel a piece of mystery metal might be. I see this in my garage all the time, when grinding annealed O-1 and/or mild steel on my bench grinder. The O-1 is like a fireworks display, while mild steel or cast iron doesn't do much.

I can't say for sure in practical terms, but would be inclined to believe a piece of W-2 or 1095 would make a better striker than a piece of lower carbon 1055 at the same hardness, for this reason.
spark_test.jpg
 
the possum said:
I don't think this is quite correct. The carbon content of the steel also changes how it sparks, regardless of its heat treatment. High carbon steel throws more and brighter sparks, with numerous branches like a sparkler, compared to mild steel. This is the basis of the "spark test" to figure out what kind of steel a piece of mystery metal might be. I see this in my garage all the time, when grinding annealed O-1 and/or mild steel on my bench grinder. The O-1 is like a fireworks display, while mild steel or cast iron doesn't do much.

I can't say for sure in practical terms, but would be inclined to believe a piece of W-2 or 1095 would make a better striker than a piece of lower carbon 1055 at the same hardness, for this reason.
spark_test.jpg
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I may be wrong but from what I understood we are agreeing just using different wording. High carbon steel sparks more not because of the heat treat so much as the carbon making the steel more brittle and easier to flake pieces off of by hand. Mild steel and cast do not spark as well because they have a lower carbon content. A grinder is a steady even pressure which gives easier eparks where as with flint you are striking downward very forcefully in a concentrated area. I have tried it with cast and it deforms or actually cuts into it therefore you cannot get sparks. The same I would assume would be true of carbon steel. The carbon is the important part the heat treat just makes it a little bit harder to help the process.
 
I believe hardness has merit. Course pearlite is difficult to cut. Recall that cast iron begins around 2.4% (?) carbon. Wrought iron has little carbon.
 
My question for The Possum is what HRC are each of those metals? Bet my bottom dollar that every steel in that chart is not at the same HRC number. If they were, then I would wholeheartedly agree with you. Which leads me to SS90s latest post. I think he may have hit the nail on the head there. In my concentration on the hardness perhaps I am not giving enough credence to the carbon. And The Possum may be doing the opposite.

I am neither a professional chemist/physicist nor a pro blacksmith. I can only rely upon those whom's research I have studied, the many practitioners of F&S that I have watched and/or discussed this with and the real world results I have experienced through extensive testing.

I say this not to brag but rather to inform people as to why I am confident of my assertions. I am not aware of anyone else who has used as many improvised strikers as I have. Nor of anyone who wore an 1/8" inch off their striker two years in a row. (In neither year was that the only striker used.) Nor anyone who has found as many NUTs (raw tinders that work with F&S), which of course required a whole lot of striking. Chars and char mixes generally catch for me in under 20 strikes. NUTs usually take 50-200 strikes.

That being said, am I the most knowledgeable practitioner of F&S in the world? Doubt it. Even if I was, there is still so much yet to be learned. I can clearly see that from where I stand!! I have dozens of things I am looking forward to experimenting with and am quite sure there will be many new ones added long before I reach the end of that list.

So, yes, I may be incorrect on this. If so, I hope that we can figure it out together. Thanks guys!
 
Looks like I wasn't very clear in my post above. I wholeheartedly agree with you guys that the striker steel needs to be hard to work. I was just trying to point out that carbon content and other alloying elements play a role as well. I can't say what hardness would be best, and if others say they've found a sweet spot at around 59 rc, I defer to their experience. I'm just saying W2 may (or may not?) make a better striker than 1045 or M2, even if they're all at 59 Rc.

This summer I saw a blacksmith with several strikers for sale on his table, and picked one up. It looked weird, like stainless steel or something, and felt light. Turns out he forged it out of Titanium. (don't know which alloy) He took a piece of flint and demonstrated its use- he said you really had to whack it hard compared to a steel striker, but it did work. He really got after it, but managed to get a piece of char cloth smoldering after about 10 stout whacks. I never would have guessed titanium would work. So, I'll try to keep an open mind.

Cheers.
 
Here's some interesting discussion: http://www.iforgeiron.com/topic/21536-flint-striker/

I keep reading that what we see is "spontaneous" combustion. Given that you are striking and peeling off steel and creating a temp where it is molten (Catch the "sparks in water and see.), that is a very unusual meaning of "spontaneous."

spon·ta·ne·ous
adjective
performed or occurring as a result of a sudden inner impulse or inclination and without premeditation or external stimulus
 
In TL's link the last poster in that thread states that he makes Ti strikers and they work, which backs up Possum. That is very interesting. Would have thought Ti was too soft. Especially since I've heard of knife makers putting carbides on one side so as the Ti wears away it exposes fresh carbides. Hmmm, what Ti do I have that I can whack on with rocks...

I would love to test several types of steel that were documented to be of the same hardness. Not feasible but I would love to have access to a series of chunks of steel such that there was a piece of each type of steel in each hardness from 57HRC to 63HRC, maybe even a couple more on either side of that range. All I have so far is items that the makers say are about X hardness and items i am unsure of the hardness of. If I ever found myself in such a situation, would be best to use carbide steel instead of rocks to minimize that variable. The carbide does get dinged up when being used for F&S but is easily squared up again. Hmmm, now I'm wondering what we can get our hands on that is harder than carbide yet affordable. Mill/lathe inserts? Who needs rocks, hey? Says the guy with five 5 gallon buckets of "flint" rocks!

In the interest of full disclosure Possum, that 59HRC comes from several knives that are from 55-60HRC and strikers I was told were 62-63HRC. One example is the 1095 at 59HRC sparks way better than the 1095 at 57HRC. Both do spark. So while I am fairly confident about that range and the sweet spot, if it were to turn out that one or more of those items was not as advertised, I might need to reassess. Maybe someday I will have access to testing.

My basic assumption on the spontaneous combustion bit is that either people were simply parroting what they had heard or the implication was the sparks did not need to be lit. (The opposite of butane in other words.) If the latter, than ferros would be considered to be spontaneous combustion as well. Both certainly appear to be spontaneous in a sense. I had always considered situations like rags with BLO on them to be spontaneous combustion, not things like F&S or ferro. TL's definition nails it: without external stimulus.
 
the possum said:
This summer I saw a blacksmith with several strikers for sale on his table, and picked one up. It looked weird, like stainless steel or something, and felt light. Turns out he forged it out of Titanium. (don't know which alloy) He took a piece of flint and demonstrated its use- he said you really had to whack it hard compared to a steel striker, but it did work. He really got after it, but managed to get a piece of char cloth smoldering after about 10 stout whacks. I never would have guessed titanium would work. So, I'll try to keep an open mind.

Cheers.
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Flint not required; ordinary-rock-in-the-rough plus high-speed titanium golf club equals dangerous wildfires.

..."What could have happened did happen at Shady Canyon Golf Club in Irvine last August, when an unidentified golfer's iron shot from the rough also hit a rock, sparking a raging brushfire that destroyed nearly 12 acres and required more than 150 firefighters and seven hours to contain.

"It might seem funny now (how it happened), but I could have burned down Mission Viejo," Parsons said."...

>>>

I have viewed the slow-mo high speed test strikes, but don't know if they are available online. Plenty of interesting info here:

http://news.uci.edu/press-releases/titanium-clubs-can-cause-golf-course-fires-uci-study-finds/

n2oz08-golfclubspark.gif


abstract from Fire and Materials Volume 39, Issue 2, pages 119–126, March 2015

"Spark production by abrasion of titanium alloys in golf club heads"

http://onlinelibrary.wiley.com/doi/10.1002/fam.2235/abstract

(complete article available through Wiley via library links, or through many professional organizations/affiliations e.g. teachers, public safety, health care, Bar Assn., engrs., etc. huge resource)

http://www.ocregister.com/articles/titanium-606130-clubs-golf.html

Some of the wildfires:

http://www.ocregister.com/articles/fire-264139-mckeown-canyon.html

http://www.ocregister.com/articles/parsons-305539-hot-golf.html

"...Then Earthman and his fellow researchers did just what you might expect: smacking rocks with golf clubs again and again in the laboratory, and recording the results with a high-speed camera.

“Every time a titanium club hit a rock, we saw sparks like that flying out,” he said. “When we compared that with a stainless-steel-headed golf club, no sparks were observed.”

Suspicions about titanium clubs already have caused some to be taken out of production, Earthman said, though they can still be found, especially where used clubs are sold...."


Flint Striker fire GOOD.
Burn down county BAD.
 
Thomas Linton said:
Here's some interesting discussion: http://www.iforgeiron.com/topic/21536-flint-striker/

I keep reading that what we see is "spontaneous" combustion. Given that you are striking and peeling off steel and creating a temp where it is molten (Catch the "sparks in water and see.), that is a very unusual meaning of "spontaneous."

spon·ta·ne·ous
adjective
performed or occurring as a result of a sudden inner impulse or inclination and without premeditation or external stimulus
Click to expand...

Yea, in my mind spontaneous would be setting the striker , flint, and char in your fire makings and coming back later to a roaring fire.
 
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