Wednesday, November 30, 2011

What is True - or what they want?

'Wrought Iron Work'
What it really is - what it really means...

Wrought Iron was the metal of the ancient smith :
• It is a specific type of material, both chemically and physically much different than modern mild steels. Wrought Iron is typically forged (hot worked) at different temperatures, when finished is softer and more flexible than our modern day steels, and is more resistant to basic oxidation (rusting).
• The truth is that real wrought iron has not been produced in commercial quantities since the late 1970's. It is basically NOT AVAILABLE anywhere in the Western world, save as re-cycled antique material.
• Despite what may be claimed by some, all modern smiths work with industrially produced mild steel bars.
• Today, most self described "wrought iron workers" are in fact using machine formed, cold twisted, mild steel elements which have been mass produced over standard forms - then arc welded together. Typically these shops employ not blacksmiths, but welders and production fabricators. Most often the poor design, and frequent duplication, of the objects they manufacture clearly reflects these limitations.

A truism among actual artisan blacksmiths :
When some one says they are producing 'wrought iron work' - the first question should always be -
"Where did you get the iron?"
 Opening segment from 'Wrought Iron Work' - new commentary / description on the Wareham Forge

So - how does this relate back to the title?

I have been concerned of late about the way the internet is shaping information. Increasingly, useful content is becoming buried under the dross - the noise. *

I was early involved in the developing internet - my first service provider was back in the days of bulletin boards (although they call that kind of thing 'chat' these days). I started working up the original Wareham Forge web site in the mid 1990's (some point about 96 - 98)/ Over the years I have been able to maintain a Google ranking 'above the fold' (top 10, often the top 5), based on longevity, lots of content - and I hope accurate (or at lest interesting) information.

But more and more, I see other sites with far less to offer (on so many levels) edging me out. I see individuals catering to the whims of an increasingly trend driven population.
'Sure, I *know* I don't actually work with wrought iron - but its what people want to find...'

Might just be me.
Expecting to be able to shape the world to what is true - rather than just giving people what they *think* they want...

*Sturgeon's Rule : 95 % of EVERYTHING - is garbage.

Saturday, November 26, 2011

Forging the BIG Time (again!)

...more on the Peterson House Project.

 In the last post, I described the creation process leading to the final design.
Now, that looks great on paper, or even as a sample piece, there are some practical realities that need to be considered.
'Expand the diameter to six inches for visual weight' :

Calculating pipe sizes against desired bundle width. Locating the tendril wrap locations.

This is a 'size as' drawing I used to visualize / convert my available stock sizes into the layout. I'm working with standard schedule 40 mild steel pipe (most typically used for water lines). One ongoing problem for me is that the material is defined by its *interior* diameter, but as an artist, I'm more interested in its *exterior* measurement. Of course all the specifications are in thousandths of an inch, which messes me up even more. (Additionally, something I just found out - and should have known - is that as the diameters increase, so does the individual wall thickness increases!)
So what I ended up with is using 2 inch (2 3/8 OD) for the central support. To evenly distribute a bundle of tubes around this circle, I have a total of four at 1/2 inch ( 3/4 OD) and four at 3/4 inch (1 inch OD).

Physical strength was NOT going to be a problem here! Physical WEIGHT on the other hand...

I've got a handy little booklet (from Canada Steel) which lists the weight per foot of many standard industrial steel stocks.
On my scratch notes, you can see the unit weight for the various pipe sizes.
Now, bare in mind that I will be working with pieces roughly 10 feet long. The central support pieces (that 2 inch) may not seem like much, at roughly 58 lbs total, but when you make that 10 feet long...
Try forging one end while your are holding (balancing) the other *with one hand*. And consider moving that length, part of it orange hot, around the shop.

My new 3 burner gas forge (rebuilt largely for this project) with the two main support tubes heating.
A larger view, giving some idea of how long those tubes really are!
Anvil? Using my heavy layout table (3/8 plate steel top) as a forging surface. Working with a 5 lb hammer.
Detail of the finished profiling. The surfaces more deformed than aggressively shaped.
Just to put the work into perspective (for those that don't know me).
Those 58 lb tubes represent over 1/3 of my own body weight!

The surfaces are deformed with slightly flattened and spiral shaped grooves. Because it is important to retain the load baring strength of the main tubes, the circular cross sections are not 'pinched' too much.

The next step was to work up the smaller sized pipe. Because this material was not really adding (much) to the structural strength, it could be much more aggressively flattened and folded. The smaller cross section also means that even as a flattened oval cross section, it was possible to twist sections.

Showing one end of the 3/4 ID pipe as forging was completed.
One last note:
On the calculation of weights is also seen the costing for the materials. For *small* objects, normally the cost of the steel is minimal next to the contribution for labour. Not so for architectural work, especially for pieces as massive as these structural uprights. Each finished support, roughly 8 1/2 feet long, will consume almost 200 feet of the various pipe diameters. The cost of this material is approximately $400. (An indication of the relative price for the finished project.)

Oh - one last thing. With the tendril wraps, and some vine work at top and bottom, each completed support unit is estimated to weigh roughly 150 lbs. (And yes, there is a 'large object tax'!)

Where DO Ideas Come From (3) - Peterson House

My current commission is for a replacement set of supports under a front porch at Peterson House in St Agatha.
The house is late 1800's, a nice 'short two story' brick, what could be considered an affluent farm house of the period. The front porch covers the entry for the original entry door, with a small balcony above off the master bedroom. The original sculpted wooden pillars have rotted out. Part of the project has included replacing some of the timber support beams underneath.
Peterson House - This image altered to 'remove' existing structure

As with any project of this nature, there is a structural component, plus an artistic consideration. I had done some work earlier in the year for the clients, in that case an extension to the existing fence. (To the left side of the house.) The first possibility was to continue working in that theme - a design based on the natural lines of vines with large leaf end terminals. As usual, I sat down with the clients and had them pour over a number of book collections of contemporary work by other artisan smiths. We marked things they liked, with me making notes on their specific comments. Later, I took a more careful look at those pieces, narrowing down the general outlines from all the specific illustrations.

From this I was able to generate a number of rough layouts. One specific structural requirement was going to come to dominate the possibilities - that there had to be a strong vertical line of metal to support the weight of the heavy porch roof and its upper deck. In most cases, this reduced the visual aspect of the potential designs to look too much like 'a beam with stuff stuck on to it'.

In the end, I was struck by the potential from something else entirely:
Runnels of slag - Slag Pit Smelt 1 - October 2011
 Neil has become my enthusiastic right hand for the ongoing experimental iron smelts here in Wareham. The massive slag block produced in our 'slag pit' smelt in October was composed of individual runnels of slag, running downwards through a bundle of willow sticks. Even at the time, we both remarked on the artistic possibilities.
So I was struck by a potential design - using a bundle of individual tubes, instead of one major structural elements. In fact, a bundle of smaller tubes would be *stronger*, with the many side wall cross sections combining to the load carrying capability. Inspired by the folding and bulging of the slag, individual tubes could be partially flattened, twisted, folded or surface deformed. The bundle would be both welded and then wrapped with tendrils of round rod. This would both massively reinforce the welds, but also add an additional decorative feature.

Of course - I couldn't really draw this concept effectively!
Faster to make a sample piece :

This is the original sample, composed of a total of five individual pieces of pipe. The central core is larger diameter (roughly 1 1/4 OD) and the outer pieces of smaller (thus more flexible!) pipe (roughly 7/8 OD). The sample is about two feet long, and has tendril wraps of 3/8 round at either end.  A number of different forging techniques have been used on the individual pieces.
The competed sample bundle is roughly four inches wide.

At this point, I played some hoo-doo with Photoshop.
- First I photographed the sample piece from a number of different sides.
- I then spliced the images together to create an impression of what a full sized support would look like.
- I then scaled that image to fit the proportions of the modified image of the front of the house (with the existing structure removed digitally).

The problem here is the at the four inch width, the bundle just looks too small in proportion to the rest of the structure. Note that there is no problem with physical strength! The original pillars were roughly 6 x 6 inches, but turned into cylinders (which reduces the apparent visual 'weight').

Next I played some games with scale - and this is what the result was :

Here you see the bundle increased in size so it 'looks right'. Measuring from the known dimensions, the bundles should be closer to six inches wide.  (The total height of each is roughly 8 1/2 feet.)
Also in this last illustration is a very rough concept for the lower hand rail. This element is not required by code, with the concrete porch only 18 inches above grade. The landscaping plan is to place a large plant into the current central gap. So the rail is more about  a 'leaning' support. (The clients actually rarely even use the front entrance to the house.)To that end, the hand rail will be a simple arch shape, further supported by some organic and asymetrical curved elements on either end.

Next : Forging the BIG Time - converting design to reality

Friday, November 25, 2011

Bill Short on VIking Age Weapons & Combat

 My readers will be interested in this note from Bill Short, researcher, author and fellow Viking Age re-enactor. Bill is associated with the Higgins Armoury Musueum, and we of DARC have worked along side him on several occasions.

Generally, his Hurstwic web site is an excellent overview of many aspects of Norse archaeology, live and that group's ongoing experiments and research.

(The following was scooped from a recent Facebook posting from Bill) 

William Short
I've been updating some of the Hurstwic web articles with additional and updated text, and with many dozens of new photos. A lot of the photos were shot for my next book and illustrate our current interpretation of Viking fighting moves from the sagas. The new material is interspersed with the old, but most of it is in the arms and armor articles:
and in the turfhouse article:
Comparatively little is known about Viking age weapons, and even less is known about how the weapons were used. This limited knowledge is due to the limited sources we have available for the study of Viking age weapons and their use. This series of interlinked articles summarizes what is known ...

Thursday, November 24, 2011

Archaeology & Experiment - Smelt at Brown University

In April in 2011 I was able to deliver a version of the 'Archaeology & Experiment' program - at Brown University. This was thanks largely to the interest of my friend, colleague and sometime mentor Kevin Smith of Brown's Haffenreffer Museum of Anthropology. The program was organized in association with Krysta Ryzewski, who was teaching a course on the Archaeology of Materials.

The full written report on this experience is now (finally) available!

There are considerably more photographs included than a normal, as the report covers not only the progress of the smelt, but also the teaching experience.

Lowering the slag bowl. Kevin Smith looking on, students observing the tuyere and maintaining ore and charcoal additions.

Saturday, November 19, 2011

the Work and Mind of Jake Powning

Sometimes you meet someone that makes you think - 'Boy, I wish that was me...'

Jake has recently posted up a series of commentaries about his most recent creation - Dagfinnr / the Day Finder :

The finished sword
The inspiration story behind the piece
A photo essay of the work in progress

I actually feel honoured that Jake Powning thinks of me as a friend and kindred spirit. 
I wish my own work was even *half* as good as Jake's.

Friday, November 18, 2011

Found on the Beach ....

.. but what does it mean?
On 05/11/11 2:41 PM, Peter  wrote:
I'm writing to you to see if you or someone you know might be able to help me identify some items I found while walking along a beach on Cape Cod in Massachusetts. At the base of an eroding bank on a marine estuary with direct access to the ocean, I found what appears to be bloomery slag and a stone that might be a bellows shield stone.
Image by Peter Hosmer

First - remember the long history of European occupation in that area. Likely to the early 1600's, I'd think 1650 for certain.
Many of the earliest colony attempts by the English had a 'make it pay' set up. Iron smelting was one of the potential money making enterprises often attempted at many colonies.
Add to this the explosion of small bloomery furnaces all over the Colonies just after the Revolution. This to supply raw iron after the Americans cut themselves off from English industrial supplies! Many of these furnace operations used locally available primary bog ore, which is a resource quickly depleted. This, plus the huge amount of charcoal required, caused many of this kind of small operation to be relatively short lived.

The stone has a hole chiseled in the center and is about 18" long and 10" wide and 2" thick.
Image by Peter Hosmer

If this was in fact a bellows shield stone, one side would quite obviously be subjected to extremely high temperatures. There should be cracking and obvious discolouration. Depending on rock type, the stone itself might be physically melted. You might even find bits of slag attached to the stone. If both sides have the same appearance as shown in your photo - none of these effects are seen. It is very unlikely this stone has been exposed to the 1100 C plus temperatures created in a working charcoal forge.

Remember that side blast forges for charcoal were in common use up through the Colonial period into the early Industrial. Depending on just were you are located, suitable coal for forge work (a specific type and quality required) might not be available. Coastal locations often had coal shipped in from England. (See Revolution effect again). Until canals / rail systems are established, many locations were forced back to charcoal fuel. So even if this stone shows heat effects, it could easily be Colonial activities.

Although you did not expressly state 'Viking Age', I wonder if you were considering this?
Remember there is absolutely *no* physical archaeological evidence of Norse activities further south than central New Brunswick (and that most likely on the Bay of St Lawrence side). (Note that the 'Maine Penny' is held as a chance find - likely via First Nations' internal trade.)  See this article by Dr Birgitta Wallace

The slag varies in size and appearance, and some pieces have shell fragments embedded in them. There is a relatively small amount of slag - perhaps a small pail full and over the course of the last 8 - 10 months could be seen emerging from the embankment as erosion took it's toll.
Image by Peter Hosmer

So - it is clear that the material is coming from the bank - not washed up out of the water? 
Slag is produced from other high temperature activities, but the colour certainly suggests iron smelting slag. The dark colour indicates the presence of iron, as does the fluid shape of the pieces. 
The shell fragments suggest a furnace set at natural ground level, this and the shape of the flow, from a slag tapping type. That type of furnace (as above) was used up to the 1800's at least, especially for small scale operations. What is the change in shore line at your location over the last 200 - 400 years? 

The small amount suggests a small furnace - but you can not tell if you are just getting the first edges of a larger field.

Remember that there is a 'rough' balance in an iron smelting furnace : 
Ore IN = Slag + Iron OUT

Now, this is pretty rough in an actual working furnace. Another consideration is yield, which is most directly modified by the iron content of the ore (but also relative furnace size, experience of the iron master, total size of the smelt itself). This all is going to effect how much slag is going to be left over from a given smelt attempt. Any way you look at it, the slag amount should be in the range of tens of kilograms. Much more than your photograph suggests.

If you really want to nail the potential dates, the shell fragments might be carbon dated. This would not be definitive, but might give you a kind of 'no older than' type of date.

I would first suggest checking local records and history to see if there is any record of Colonial iron smelting activities. Such are usually noted, both as 'proof of progress' in a settlement - but also because such operations usually were taxed as well!

As Regular Readers know, I often take this kind of request and turn it into a blog posting. Be Warned!
(In fact, it was the time I was spending on this type of information that lead me to start this blog in the first place.) If you want to know more about the mechanics of contacting me for a personal research request such as this, check the 'fine print' published on the web site.

Sunday, November 13, 2011


"We are the 99 %" is a great rally cry.

It is not a statement of principles, or a demand.

I got lead into this via Jim Wright : Stonekettle Station :

And Jim had suggested taking a look another (opposing) viewpoint :

Eric Van Newkirk : Standing on the Shoulders of Giant Midgets :

Go off and read all those. You might be gone a bit if you read some of the comments attached (I certainly took the time - and felt it was worth it).

The following list was placed in the comments to Eirc's article 'Welcome to the Occupation':


1. Repeal of the Patriot Act

"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." -- Fourth Amendment to the Constitution

Forty-five days after 9/11, Congress passed the USA PATRIOT Act without reading it. This new law was supposed to protect you from terrorism, but it has really left you unprotected against lawless federal agents. The Patriot Act contains numerous violations of the Fourth Amendment. It gives federal agents vast new powers that have been abused to investigate innocent Americans.


3. Forced Acquisition of the Federal Reserve for $1Billion

No Congress, no President has been strong enough to stand up to the foreign-controlled Federal Reserve Bank. Yet there is a catch - one that President Kennedy recognized before he was slain - the original deal in 1913 creating the Federal Reserve Bank had a simple backout clause. The investors loaned the United States Government $1 billion. And the backout clause allows the United States to buy out the system for that $1 billion. If the Federal Reserve Bank were demolished and the Congress of the United States took control of the currency, as required in the Constitution, the National Debt would virtually end overnight, and the need for more taxes and even the income tax, itself. Thomas Jefferson was concise in his early warning to the American nation, "If the American people ever allow private banks to control the issuance of their currency, first by inflation and then by deflation, the banks and corporations that will grow up around them will deprive the people of all their property until their children will wake up homeless on the continent their fathers conquered."

Article I, Section 8, Clause 5, of the United States Constitution provides that Congress shall have the power to coin money and regulate the value thereof and of any foreign coins. But that is not the case. The United States government has no power to issue money, control the flow of money, or to even distribute it - that belongs to a private corporation registered in the State of Delaware - the Federal Reserve Bank.

4. Re Investigate the Attacks of 9-11-2001

More and more evidence is being released to the public surrounding the suspicious circumstances surrounding 911. This measure would be included in the list of demands to show that the original investigation was significantly flawed.

5. What to name the Occupy Wall Street "Demands"


which essentially said corporations can spend as much as they want on elections. The result is that corporations can pretty much buy elections. Corporations should be highly limited in ability to contribute to political campaigns no matter what the election and no matter what the form of media. This legislation should also RE-ESTABLISH THE PUBLIC AIRWAVES IN THE U.S. SO THAT POLITICAL CANDIDATES ARE GIVEN EQUAL TIME FOR FREE AT REASONABLE INTERVALS IN DAILY PROGRAMMING DURING CAMPAIGN SEASON. The same should extend to other media.

7. End the War On Drugs

The war on drugs has been going on for more than three decades. Today, nearly 500,000 Americans are imprisoned on drug charges. In 1980 the number was 50,000. Last year $40 billion in taxpayer dollars were spent in fighting the war on drugs. As a result of the incarceration obsession, the United States operates the largest prison system on the planet, and the U.S. nonviolent prisoner population is larger than the combined populations of Wyoming and Alaska. 21 Sep 2011 - 15:17 21 Oct 2011 - 17:17 6570

8. Require all Corporations to have Labour Representatives on Company Boards

9. National Repeal of Capital Punishment 

10. Nationalize Health Care

11. Free education Kindergarten through college

Redraft education financing legislation. Lower educational expenses for students instead of raising tuition costs. Pull money form the "WAR" system to refund education and continuing education. Forgive Student Loan Dept or restructure the Student Loan System so that students are not punished for self improvement and made into corporate slaves upon educating themselves. Standardized testing does not account for stereotype effect or cultural differences in learning styles in elementry schools. Reform education to make it either free or affordable to all. Reappropriation of tax to focus on educations subsidies.

THIS REINSTATES MANY PROVISIONS OF THE GLASS-STEAGALL ACT. --- Wiki entry summary: The repeal of provisions of the Glass--Steagall Act of 1933 by the Gramm--Leach--Bliley Act in 1999 effectively removed the separation that previously existed between investment banking which issued securities and commercial banks which accepted deposits. The deregulation also removed conflict of interest prohibitions between investment bankers serving as officers of commercial banks. Most economists believe this repeal directly contributed to the severity of the Financial crisis of 2007--2011 by allowing Wall Street investment banking firms to gamble with their depositors' money that was held in commercial banks owned or created by the investment firms. Here's detail on repeal in 1999 and how it happened: . 

13. Outlaw flash trading

14. End Gender Discrimination - Equal Pay for Women 

15. Office of the Citizen

16. The United States must sign and ratify all human rights agreements with all other countries


There is a second set of 'demands' listed, via the Huffington Post. This has been compiled by on the street interviews. Its a lot less structured, not surprisingly:

I realize that as a 'movement' - Occupy Wall Street has virtually no structure. Sorry, since there *is* not any structure, no leadership, no agreed to principles - its just a flash mob. No one really should be surprised there is no control, and that things get out of hand. It is more remarkable how little violence there has been, the lack of command and control taken into account.

You Canadians involved with the Occupy Movement!

Read that list again. See anything that even applies to Canada? 

Maybe a couple of the most vague human rights related clauses. Almost all of which are actually ongoing processes already.

Its hardly surprising why most of the rest of us in that '99%' don't understand what this is all about, when the PARTICIPANTS don't even have much of an idea....

(and yes Steve, I know you warned me about political commentaries!)

Saturday, November 12, 2011

Sauder on SMELTING

Lee working with an Aristotle Furnace - Smeltfest 09
Lee Sauder, with his smelt partner Skip Williams, are in no doubt largely responsible for the current 'Early Iron Iron' movement in North America. Their quick and open friendship and guidance have been of critical importance to my own development and understanding of the Bloomery process.

Lee has recently re-vamped his own web site :

Most importantly, he has made a number of his research articles available as PDF downloads:
(this list copied directly from Lee's site)

Published Articles:
A Practical Treatise on the Smelting and Smithing of Bloomery Iron
This is the paper I wrote for Historical Metallurgy back in 2000, reporting our early work and challenging some of the prevailing notions about bloomery smelting.
Update on "The Practical Treatise"
An excerpt from a paper I expect to be published in the proceedinbgs of the 2010 conference. This summarizes some of the changes in my technique since the above paper.
The Basics of Bloomery Smelting
An introductory paper I wrote for The Anvil’s Ring back in 2000.
Practical Bloomery Smelting
A paper from 2001 for the Materials Research Society. Similar to the HMS paper, but a lot more concise.
Aristotle's Steel
Another paper forthcoming in the HMS 2010 Conference proceedings, describing an easy way to convert iron into steel.
A Journey Into Medieval Ironmaking
Written for the Anvil's Ring in 2010, reporting on my trip to England, and the work inspired by it.
  Shop Reports:
Bloomery Construction
Step by step instructions for building a clay bloomery furnace.

Friday, November 11, 2011

Afghanistan ... and Viet Nam

So now we're getting out of Afghanistan...

 To Hear this Sound Clip

... And now, of course, we're leaving Vietnam... We're leaving through Laos, Cambodia and Thailand. It's the overland route. It's the long way out. Ya gotta go through China and Russia to get out that way. What'll we tell them, man? "We'll only be here six weeks. Just looking for the Ho Chi Minh Trail!" Wow. Maybe they'll buy it, y'know. Of course, you have to remember why we're over there in the first place...
Oh, yeah! It always comes to me. To free those people...
So they can have industry- yeah! US industry- YEAH! Those are the middle two letters of the word 'industry'..US. And that is our job around the world. Run in, free some people and whip a little industry on them. "Here's your industry. Cool it awhile, willya?"
Then you have to have to remember the sexual side of Vietnam which a lot of people don't notice. ...  But they're always afraid of pulling out. That's their big problem, y'know? "Pull out? Doesn't sound manly to me, Bill. I say leave it in there and get the job done!"
'Cause that is, after all, what we're doing to that country, right?

George Carlin

The more things change, the more they stay the same.

                   Afghanistan                               Viet Nam


'begins'        October 7, 2001                       November 1, 1955

'ends'         'Home by year's end' - 2011        August 15, 1973

'duration'    10 1/4 years                              19 1/2 years

troops        131,000 (Coalition total)             536,000 (US)

deaths        2713 (Coalition total)                 58,220 (US)

%               .02 (1 in 48)                             .1 (1 in 9)


'begins'        October 7, 2001                     unofficial

'ends'         'End of  December' - 2011        unofficial

'duration'    10 1/4 years               

troops            3,000                                 '30,000'

deaths            158                                    '117'

%            .05 (1 in 19)                            .004 ( 1 in 256)

Data gathered from Wikipedia, so should be considered 'soft'

I was intending to wax poetic about 'never should have done it'.
But those numbers should depress the hell out of anyone reading them.


Wednesday, November 09, 2011

Slag Pit Two - Report Ready

Image by Vandy Simpson
The full report, with many images, has been published!

Go to the Wareham Forge Iron Smelting Documentation : Slag Pit 2 - November 5, 2011

Monday, November 07, 2011

'It came from the PIT'...

November 5, 2011
'Celtic Iron Age' slag pit with Short Shaft Furnace.
Participating: Darrell Markewitz / Neil Peterson / Ian Fleming / Lloyd Johnson

Bloom after sectioning

Total Time : 3 hours 45 minutes (main sequence, not including compaction)
Total Ore : 19.2 kg industrial taconite
Total Charcoal : 45 kg (33 kg graded)

Total Bloom : 6.4 kg (including smaller fragment)
Total Yield : 33 %

I am extremely pleased with the operation of the furnace and the results!

It is clear that the results of the October 9 smelt were entirely due to the poor quality of the ore. With virtually identical layout, this second smelt using the slag pit system produced an excellent return of nicely compacted workable iron. The bloom was virtually slag free when it was extracted, with very little lacy 'mother' attached. Later spark testing indicates the metal has a slight carbon content, a bit less than standard 1018 mild steel (so about 1010 equivellant?)
It should be noted that our normal high volume air  and furnace layout produced the type of dense 'puck' style bloom we normally expect.

Slag block exposed
The slag pit system worked virtually flawlessly, at no point was there any obstruction to the tuyere. As the taconite contains only a small amount of silica, the available slag was also considerably less than last time. Pieces of the clay 'donut' can be seen in the upper area of the pit itself, where they had broken free and sank dowwards as the heavier bloom had developed. Although not entirely clear in this image, the liquid slag hand run down through the central hole and eventually carbonized the supporting sticks.

The furnace itself remains in almost perfect condition! (In fact, the repairs made after the first use proved more durable than the original structure.) With a bit more care taken, the furnace was slid on wooden rails off to one side, then returned to place after the slag block was excavated and the pit re-filled. There is no reason that this furnace, with the original tuyere still in place, could not be used for another smelt.

Excellent work all round!

Thanks to Ian and Lloyd, who provided some much needed fresh hands for the compaction stage.

Saturday, November 05, 2011

Slag Pit Two

(or 'If first you don't succeed...')

DARC undertakes its annual fall smelt the weekend following Halloween each year. Although we are starting background research (on clay bodies) to return to our Hals / Icelandic series, we really did not have enough time from lab report through commercial sources to mount anything useful. I also wanted to give the 'Celtic Iron Age'* slag pit system one more try - this time with a half decent ore!

Furnace Layout
Part of the utility here is that we were able to save the actual furnace from the last smelt with minimal damage. The primary set up work (I thought) was going to be in building the pit portion of the set up. As you can see from the layout, this consisted of digging out the loose packing from the last smelt, then planting in another plastic pail.
A note to other experimenters: Although the original idea for using the plastic pail was based on simple ease and speed, in retrospect this proves an excellent method. The pails are standard - and easily acquired. As we found out from our last experiment, one holds about 40 kg of slag.
Detail of Base Layout
Acting on some advise from Lee Sauder (and after looking again at the work of others and the archaeology), I have placed a 'donut' of clay at the base of the furnace, to constrict the movement of slag into the pit. Based as much as what I had on hand, this material is a mixture of clay with about 50% charcoal fines. The sticks packing the pit are also much less uniform than those used on October's experiment. Here I did not trim off the smaller side twigs from the lengths. These were also cut from some branches I had soaking for a month in the pond (hoping to sprout them). Again, I will use the wet straw as a pad at the bottom, which worked extremely well last time. If I have any concern with this layout, it is that the space below tuyere level is going to be reduced to about 8 - 10 cm, which I think is going to prove a bit tight. Balanced against this is that the clay plug is very thin, and can easily be poked through with a rod from the top of the furnace.

View down inside the furnace - showing the clay donut. 

The furnace was generally in good shape, although there had been some construction problems originally that did lead to some cracking. Not surprisingly, the thing weighs some 50 kg +, and is bloody awkward to move for one person! The net result was even more piece breaking off and needing patching.

Completed furnace
 The extend of the breakage and repair work can be seen via the colours on the surface. The spotty grey material is new clay that was added to patch in some of the pieces. The very red coloured clay here is the original furnace surface. You can also see several of the loops of heavy fencing wire I bound around the body 'just in case'. Expecting some problems with venting via these cracks, I have buried the bottom 20 cm or so of the furnace with loose packing (mix of dirt, sand, ash & slag fragments) left over from past smelts. This material is slightly damp via the rain we had earlier in the week.  You can see that I have shored up the front wall with a double row of house bricks. (The plastic bucket lid was just temporary for over night.)

As ore was the primary reason for lack of a bloom last time, a better quality ore is certainly indicated for this experiment. There are three possibilities (easily) on hand:
Industrial Taconite
Gromps from past smelts
Forge scale sweepings
For now, the plan is to use the half pail of taconite (given by Mark Puigmarti), a total of 21 kg. This material appears pre roasted (black colour and mildly magnetic). It is untested, and the actual iron content is unknown (although normally this type of material is in the 65 % Fe range). This quantity is enough for a small to medium bloom - estimated in the 5 + kg range. If anything, it may prove a bit 'dry' for the best use of a slag pit furnace.

Wish us luck!

(at least we *think* we know what we are doing!)

* For those sticklers for absolute historic accuracy:
I'm referring to this series as 'Celtic Iron Age' primarily because of the end use of this series. This a potential full working demonstration at the Earth, Air Celtic Festival in August 2012. Yes, I realize we are really sticking a Viking Age short shaft over a pit, which really is not the same as the know Celtic Iron Age furnaces. Bare with me - this is still early days with this experimental series! (Working from what is known to work back towards a more accurate duplication of a possible historic method.)

Wednesday, November 02, 2011

Stone Age to Iron Age?

The question posed was "could [North American] Pleistocene man have made iron (by accident)?" From a user story perspective seemed easy enough: Man camps at base of mountain (with ore outcroppings); man uses iron ore boulders as fire perimeter; man builds massive fire (i.e.: tribal celebration): Mother nature helps with proper environmental conditions (perhaps storm or strong wind surges);Fire burns to ashes while all sleep. Next day - small lumps of partially reduced ore (iron) found in remains of fire.
Thomas - Missouri

First thing : No one has figured out how people originally figured out that red crumbling rock could be made into anything like metal - or how it was actually done in practice.

(I had to do some Google / Wikipedia work here to supply some dates for the next bit - which because of the sources have to be taken with a grain of salt.)

Humans show in North America something like 15 - 10,000 BC (depending on what research you look to). The first record of human copper working is something like 9000 BC, but that is in the Middle East. I found some references to copper use in the Great Lakes area to something like 4000 BC. First record of actual copper smelting in the new world is not till 600 AD - and that is in Central America.  Balanced against this is that the bulk of tools used in North America remain stone - up to European contact.  I'm not sure North Americans (specifically) ever independently developed any smelting technologies.

Meteoric iron is known in ancient times, but as far as I am aware, the only surviving artifact examples are mainly from cultures that already have some metal working experience. Meaning working native copper or gold, which was found in alluvial deposits in lumps big enough to cold hammer work.
In North America, the exception I know of are the Inuit of Canada's North, who would pick up iron meteors off spring ice, then cold hammer fragments into small points and edges. (In fact there is was a well documented huge meteor that was exploited seasonally - until the Smithsonian grabbed it in the late 1800's!) Note that most of the earliest iron objects from the Old World are also iron meteors - indicated by the high nickel content (sometimes 7 - 15 %.) Metallic iron without nickel is the signature of human produced material.

So a case might be made for applying copper working traditions to extremely rare meteor fragments - working cold.

Generally, the first regular intended production of metallic iron is set at something like 2500 BC, again in the Middle East. (For an overview see the Wikipedia topic "Iron Age" ) There has been suggestions made that there is a relationship between copper ore smelting process, using ores 'contaminated' with iron oxides. (Small ball bearing sized fragments of metallic iron have been found in slag blocks remaining from copper ore processing.)
There certainly appears to be a human progression from ceramic kilns to copper melting furnaces to copper smelting furnaces into iron smelting furnaces (which in turn get larger and hotter - and more efficient).

As to the concept you mention : Rocks with ore + hot fire (hardwood + wind) = reduction to metal

Reducing iron oxide in ore down to usable metallic pieces is considerably more complex than just applying heat.

I certainly have seen a number of times that a too aggressive ore roasting fire has resulted in slag formation on the surface or as small fragments remaining in the later ashes. This likely indicates local patches of reduction, but this is only part of the larger complex series of reactions that converts iron oxide ores into usable metallic iron.
(A good explanation is in : "An attempt to define archaeo-metallurgy"  by Arne Espelund  - published in 'Early Iron Production" edited by Lars Norbach).
You have to not only chemically reduce the oxide, but also provide some system to sinter the individual particles into a larger mass.  Frankly, the whole working system is so "complicated, but not complex" (as Espelund states) that I can not imagine anyone stumbling on to a working process entirely by accident.

This should not prevent you from experimenting with the process yourself!
Good news is that there are some people who have done some ground work and published excellent operating guidelines for building small bloomery furnaces.

Two notable examples:

the Flue Tyle Furnace by Sauder & Williams :

the Econo Norse Furnace  by DARC :

You may be eventually looking more towards earlier / more primitive bowl shaped furnaces. To that end, take a look at some of the (excellent) experimental work being done in Europe, primarily at those at various living history museums.

As regular readers know, I often source blog posts from detailed replies I make to specific questions that come in as personal e-mails. Take this as both a complement, and the 'cost' of getting a detailed reply to a question sent!

Tuesday, November 01, 2011

Slag Pit Smelt - Report ready!

For those interested in Early Iron: This years Thanksgiving weekend smelt was a loosely 'Celtic Iron Age' slag pit furnace. The superstructure was our standard 25 cm ID x 70 cm tall short shaft. This furnace was built over a roughly 40 cm deep by 25 cm dia pit, filled with small branches standing on end. The ore used was an untested rock ore from Bratton's Run in Virginia. This proved the failure point in the experiment. The ore proved to have hardly any iron in it!

But we did get a mother beautiful slag block...

The full photo essay report can be found on the main Wareham Iron Smelting site :


February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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