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I Forge Iron

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Bog iron also can contain phosphorus which is also a hardening agent.  The bloomery process used by the iron age Scandanavians to make bog iron ore  into iron can produce steel as well as wrought iron. I find it funny that forging in charcoal which was the way it was done, was not considered to be a sufficient carbon donor: "Bone coal was a necessary ingredient". Of course case hardening in charcoal does work and was used historically.  They mention experiments using bone charcoal; but don't mention the control of doing the same thing with regular charcoal.  Also the use of bone is not a wild new conjecture.  My 1915 copy of "Cementation of Iron and Steel", Giolitti, mentions bone as a cementation material.

So basically that article is claiming much more than the evidence stated supports.  Perhaps it was trimmed down or just hyped for publication. It is fairly common that the perception of what was happening was not the reality.  For example Steel was considered a more refined form of iron, as it was harder, whiter, etc.  So what happens if you run your smelter a bit longer?  You tend to pick up more carbon in the metal making it steel and then finally cast iron.  So the "more refined" iron might be steel but in actuality it was not more refined but picking up more carbon as a contaminant!

"The Celtic Sword", Radomir Pleiner, has good information on the use of phosphorus as a hardening agent in early ferrous swords. (Nowadays it's considered a contaminant as it makes the steel cold short.)

I would like to read the academic journal article(s) to see what the actual findings were!

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I would also like to see the evidence the incidence of bones, charred or not, from forge sites.  And if the forge is associated with a dwelling how do you distinguish bones used or intended for use by the smith from the remains of the smith's family's dinner.  

Certainly, the article points out a possibility but without more hard evidence it is mere speculation.

As Thomas says, maybe the academic article has more meat to it rather than the dumbed down popular version.

"By hammer and hand all arts do stand." 

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I agree that this was a dumbed down version, it smelled of "click-bait" when I found it, but it was interesting enough to share here.

Did a bit of searching both in and out of this article, and the only thing I could find so far was what they linked in one of the hypertexts in the article, an article from the Norwegian archaeological review in 2004 by Terje Gansum. To find it search for "gansum 2004" and it will be the first thing to pop up. It references what appears to be a smithy where they found bones and more specifically bone coal along with charcoal and kilos of iron scale. It goes into potential reasons why they would have the bones there, but there is no concrete evidence as to why it would be there. It has alot of educated guesses based on known rituals of the time, as well as what is known of smithing from the sagas that have survived.

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I think the lack of proper cites and exaggerated excitement of discovery is academic puffery. It reads like something published by a student in a place that would accept the submission. "Big Think" :rolleyes: The author doesn't show very much knowledge or understanding of smithing. I also tend to be skeptical of a "scientific" publication that quotes Clark's Law, especially in the first couple paragraphs. 

One of the articles at the bottom of the page says, "Vikings" may have been a job. This isn't a mystery, every in question, "Viking" transliterates as "raider," the verb form being to "Go Viking."

I'd be more likely to think that bone was included in smelts to provide calcite fluxes to help remove impurities. 

It was an interesting read but I don't think it's anything new, certainly. Worth reading, thanks for the link.

Frosty The Lucky.

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Of course this would be an easier method than filing a couple of blades down; feeding the filings to geese and then collecting and resmelting the "results"...another method of getting more phosphorus into a blade...

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Mr. Powers, I'm guessing a blade made that way would be named Gaesakukur.

Frosty, it took me a bit to figure out that they do site their sources, but they use hyperlinks to send you directly to the site/book/article instead of a way that anyone who's older then a cell phone would recognize. One site they linked to was pretty interesting, it showed a slideshow of a "traditional" icelandic sod smelting furnace. 

http://www.hurstwic.org/history/articles/manufacturing/text/bog_iron.htm (I'm not sure if this link violates tos. The page doesn't have commercial aspects to it, but the mother site does. Please remove if it is a violation)

And yes, this there wasn't any new info in the initial article, they just rewrapped it like a fruitcake that gets passed along to the next (*cough* sucker *cough) friend each Xmas

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Be interesting to see the phosphorus & calcium contents of the slag produced in early medieval bloomeries to try to see how they were fluxing the smelt. (And if it differed by distance to the source of calcium...)

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1 hour ago, Shabumi said:

Frosty, it took me a bit to figure out that they do site their sources,

But not in a useful manner. The hurstwic article is an old one, I've seen it posted here and discussed some time back. THIS is a good article, they aren't claiming something new other than trying to demonstrate how they believe iron and steel was made in the day. 

One thing I haven't seen mentioned though is how someone with experience making and refining blooms gets to see various grades by how it reacts under the hammer and it's color as it's tapped. There is an excellent video of a Japanese bladesmith who starts with which bend in the special river to collect iron sand through the finished blade. He carefully examined the "bloom" from his tatara, picking and poking with the occasional thump from a hammer. He only refined the selected portions of the bloom to make a sword. Other portions of the bloom were saved for: lesser blades, tools, utensils etc. The cast iron pile was put in a different part of the shop all. The narrator did a very understandable job of describing the whats and whys of every step. 

Frosty The Lucky.

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A bloomery can produce a wide range of materials.  It's instructive that the Japanese sword smith identifies, sorts and uses parts of that range to make an item that profits from the various different materials produced.

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Not sure of relevance- but I do know that in "color case hardening" or... color... im drawing a blank on the actual term- on antique firearms, that bone charcoal was traditionally used, mixed to give the varying colors in the receivers bluing. It created different heat levels in the fuel wrapped/packed around the part in a steel container... 

Could this possibly be something similar with the bone charcoal use? Creates a different heat control with mixed fuels?

Just a weird thought after reading the thread.

H012CC-closeup.jpg

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It's a good thought; however it more the chemical activity of the carbon bearing materials as you want a steady and high temperature.  The book I mentioned on the "Cementation of Iron and Steel"  goes into great details on the subject---like You can case harden with diamonds.  You can case harden without the presence of CO, etc; the description of the experiments used to prove their contentions I found interesting and very very clever!

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