Thursday, November 11, 2021

Remembrance Day (10 lines #3)

"... soon no one
will march there
at all. "


At what point do we ourselves become those tired old pharts, lost in dimly remembered stories, maybe which have some rambling point. but beyond the understanding of the oh so younger listeners?
Knowing full well that although our hearts are strong, our bodies no longer can carry the load out, our perceptions not quite sharp enough to protect us anymore.

This has been a rough three months for me, coming up to my 67th year.
Too much of small things that just seem too damn difficult, of afternoon naps, of trembling hands and stumbling words.
Maybe not so serious yet, but no longer able to keep up with my friends, all almost a decade younger.
Having finally gotten all the tools and toys - just about the time I can hardly effectively use them.

Hearing just now the average age of the so few remaining WW2 veterans is into their 90's.
Doing some math and realizing I now would only be the very youngest of the Viet Nam era soldiers that shaped my own perceptions.

Watching a culture shaped by internet experts and politically correct everything increasingly not understanding why we need to Remember and ponder, at least for an hour, one day a year.

Has it *ever* been 'never again'?
Or more like the message has always been 'make it count'?

As we each, separated, but in spirit, not alone, raise a glass.
'To Absent Friends'

 

 

Those who know me, also know that Remembrance Day has always been important to me. My own military service, although limited and brief, happened at a critical age, and has shaped me deeply. This was the early 1970's, and I had lied about my age to sign up to the Canadian Army Reserves. Just about the same month of the Fall of Saigon. Over the next four years, a number of my instructors, and latter one of my oldest and closest friends, had served in there. Which itself would shape my perceptions and character. 

Over the decades since, I've watched the controversy over 'The Day'. Largely from civilians so far removed that they just don't understand any of it. Watched the cycle of every twenty years, Never Again get submerged under 'It's good for Business', as another 'generation' of young innocents, nurtured on advertising / propaganda, become meat for the grinder.   

Seeing full well that major corporations, spewing waste to sell us endless crap, are engineering a future of human turmoil, where once again the young will be called upon into destruction, to support that very few who have it all. 

 

 

Friday, October 29, 2021

Sell Out (10 lines #2)

 

You can’t be serious, they actually will sell these resources to us?

Certainly, our analysis of the overall cultural matrix shows a consistent historic pattern of destructive exploitation, usually benefiting the personal greed of individuals, most commonly by more technologically advanced groups over those resident at the resource sites. 

Excellent, mounting an invasion is so time consuming, and the costs involved certainly adversely effect our own final profit taking. 

Further, there is no centralized authority, outside of their ‘United Nations’, which is in reality more like some kind of in-effective debating society, with little to no power to enforce decisions even if they are made. 

You mean we will be dealing with separate sub groups, making individual deals for each commodity and physical location?

Even better, they have this obscure concept about trade goods, fully expecting a short use life, coupled with rapidly modified designs based on what they call ‘latest style’. 

You are actually telling me we can exchange valuable raw materials for poorly made consumer goods, sure to fail?

Yes, and they have little appreciation for waste management, hardly are concerned about environmental degradation, and will be fully expecting fast depletion of any resources required in the production of these goods.

Really, we can even use sloppy manufacturing to make this junk, on their soil, then simply walk away from the mess once we have stripped the place?

I know, it is simply unbelievable, and to quote one to their own famous poets : 'What fools these Mortals be’!

Hardly a new concept - from 1964

I actually wrote this piece first, then in looking for something to use as an illustration, got thinking about Science Fiction I had read, way back in early high school. 'To Serve Mankind' first came to mind, then this one ...

The 10 Line Challenge' is to write a short story using only 10 sentences. The piece is formatted here so to make the sentence count clear. This (again) may be cheating just a little, as some of those lines are a wee bit on the long size. 

The first contribution was 'Globes'

Monday, October 25, 2021

'Weathering Heights' - Oct 30 IRON SMELT

 Those who have been following the work on Icelandic / Hals - Phase 3 have seen that the originally intended set of experiments has been modfied :

Part A / June 2021- full build using Icelandic simulated clay mixture, thin walls with sod cone support

June - after extraction
Part B / September 2022 - repair and re-use of furnace, after exposure to weather.

September - after extraction
Part C / (June 2022) - repair and re-use of furnace after over wintering

Part D / (continuing) - long term observation of furnace as it naturally erodes

State of the furnace 9/21/21

 

A combination of factors contributed to more damage to this furnace than had originally been foreseen. Additionally, September at Wareham was exceptionally wet (September 14 saw 5.5 cm on that one day alone, where the historic average for the entire month was 7.8 cm). Combined, the remaining clay liner had slumped forward 17 degrees over the first three weeks since the September 4 firing. Although it was perhaps possible to recover and repair this furnace, it certainly would never have survived in viable condition over an entire winter exposure. 

For that reason, it was decided to skip the spring re-use, and proceed directly to Part D - recording the furnace as it weathers over coming years. (The hope is for a full decade of observations, which will certainly depend on my own longevity!)


 The next smelt will mark the start of another long duration exposure project. 

Another 'clean' sand pad had been built earlier this summer, 8 x 8 feet square. This was framed by standard 2 x 4 lumber, set on narrow edge, then filled with course sand. On to this was built a 'standard Short Shaft' furnace, clay / sand / manure mix walls, set on a low stone block plinth. (This build detailed in an earlier blog post, first segment). On consideration of the possible recording scheme detailed below, an additional 15 cm of wall height was added. The total shaft height (above 10 cm plinth) is now roughly 85 cm, with an expected stack height (above tuyere) at 65 cm. (Re-cycled clay material included both ash and charcoal fines, resulting in the colour seen below)

 

Finished clay build - chalk lines at 10 cm

The intent is to run a 'typical' smelt, using roughly 30 kg of DD-1 analog (red oxide with 10% flour binder). Then leave the furnace plus any debris created in place. As there are no special problems expected from this well proven build, layout or ore, the smelt itself is most likely to follow the pattern of (many) earlier experiments.

The acquisition of several accurate instruments by Neil Peterson has suggested adding some more detailed measurements as the experimental element during the actual smelt. To this end, a number of new fittings were created (as detailed in an earlier blog post, lower segment).

  • A new air volume gauge will allow for recording 'in line' amounts (in finer detail than required)
  • The existing air pressure gauge, although an older dial / analog type, can be included
  • A 'Y' fitting equipped with a simple one way valve will permit the existing 'Norse Smelt Bellows' to be integrated into the air system. As the current high volume air blower is normally fitted with a sliding air gate, it will be possible to switch to human powered air supply over frequent (if short duration) periods over the whole smelting cycle. 
  • The furnace itself will be equipped with two sets of small diameter holes, allowing for frequent internal temperature measurements. Spaced every 10 cm of shaft height, one set above the tuyere, the other located at 90 degrees.

The projected outline would be to have :

  • Air volume recorded constantly (via computer lap top input), but most likely reported as 5 minute intervals.
  • Air pressure recorded as a rough visual average every 5 minutes
  • Human Bellows utilized for a five minute period, once every 30 minutes, with operators alternating. 
  • Temperatures recorded individually over the set of ports, once every 30 minutes. 

It is expected that once the extraction process starts, further measurements will not prove possible. An attempt to video the extraction will also be made.

Combined with the normal cycle of charcoal and ore additions (typically something every two minutes) plus the usual clearing of slag blockages and tapping events, this will make for a fairly busy activity level for this smelt! 


Note : The details on the two Phase 3 smelt experiments were documented in a more formal style, available as a PDF : Phase 3 : P3 A & B

The full web site has a number of individual reports covering the Phase 3 work.

Tuesday, October 12, 2021

in EXARC Journal 2021 Digest


 I am quite pleased that a condensed version of my article 'Standardized Reporting of Bloomery Iron Smelting - a modest (?) proposal' has been included in the 2021 EXARC Journal Digest.


 
The complete Journal version can be seen  HERE
 
The original version, as prepared for the 2020 Woodford Furnace Festival, is available as a PDF (off the Wareham Forge Iron Smelting web site)

Sunday, October 10, 2021

Furnace Build - October 30 Iron Smelt

 

Considerable help from Neil Peterson and Gus Gissing.
 
Build for the October 30 iron smelt :
  • 28 cm ID
  • 70 cm stack
  • on 10 cm stone plinth
  • lower walls at 6 cm thick, tapers to 4 cm
  • set on an (8 x 8 foot) clean sand pad
 
This furnace will have our 'standard' layout, and will be used for a 'typical' iron smelt sequence / 30 kg analog :
  • The main addition will be constant monitoring of input air volumes, via Neil's new (accurate) meter. The M2 smelting bellows will be mounted in tandem, allowing duplicate measurements on an occasional basis.
  • The overall debris created through this smelt will be left in place (and recorded)
  • The furnace will be allowed to naturally decay over time, as exposed to summer rain and winter snows. This will be documented on a regular time frame, ideally over the next decade.

Saturday, October 09, 2021

Available = TREADLE HAMMER

This is a light weight treadle hammer I built years back. This was my first attempt at a larger tool, so at best only an 'intermediate' quality. This is an excellent tool for surface embellishing using decorative punching. It allows for careful positioning of forming tools or dies (basically 'hands free' striking).


(Sorry about the image quality)

The working head is built around a 12 inch long piece of rail track, roughly 90 lbs.
The bundle of springs 'floats' that weight. 

The framing is heavy angle iron - so not as rigid as it could be?
The board on the foot peddle is not fixed in place, but is the size of the framing there.

The whole thing stands over five feet tall (68 inches), it is 30 inches wide by 32 inches deep. The base is 30 x 20.
It is sized for my body height (at 5 foot 11 inches), comfortable to work with my long legs. The working table is set to 38 inches from the ground. 

The table is made of a disk of 1 inch thick mild steel, total diameter at 9 1/2 inches.

The striking head is 5 x 5 inches, with two 1/2 diameter holes set on 3 1/2 inch centers, which were intended to allow for the attachment of top forming dies.

It would at least be theoretically possible to somewhat disassemble. (Not sure what the total weight is) You can see the large bolts that hold the head too the impact (leaf) springs, leaves and return springs to the frame. 

There might be some adjustment possible in the return spring to treadle board attachments (these all are bolted) but I've never tried to change any of those alignments.

I had built this just about the time I was switching to full time, the welds are stick (so not the best, I can tell you). I never ended up using it. At the time I was doing a lot of decorative punch work, this would allow for one hand on the bar and one hand using a handled punch. David Robertson got interested in small air hammers just as I finished this build - and I ended up funding that project, and getting my first 50 lb air hammer as my large power tool. 

This sat in the corner of my main workshop (unheated with dirt floor) for a long while. Eventually I moved it out to the front entrance overhang, so it has been stored out of doors, but out of the rain. Obviously there is surface rust (it never was painted). 

 

UPDATE : 

SPOKEN FOR

My old friend / sometime student Gus Gissing will be the new owner.

Friday, September 24, 2021

Grasshoppers, Hunkering Down - and ‘Alas, Babylon’…

 This is a previously unpublished commentary written in April of 2020 - at the early stages of the COVID-19 lock downs. On showing the piece to some close friends, it was pointed out to me, given the general insanity of that time, that mentioning stockpiles and preparations to the outside world might not be so wise.

With some revisions - I thought it might prove of some value as 'historic perspective', now some 18 months since lock downs started here in Ontario. There has been a new section added, after the original set of reference notes.

Note - Some of the included links may have changed since this piece was originally written.

 

Grasshoppers, Hunkering Down - and ‘Alas, Babylon’…

Note : I started this piece on March 20, and things have evolved as it has been worked up. This essay may prove a bit more rambling than even my normal, as this is part documentary, part commentary - and a healthy dose of self therapy. 



On Hunkering Down *

One of the guiding principles of my life was born out of growing up in the 60’s and 70’s. The Cold War, with the very real fears of possible nuclear exchange. ( I don’t specifically remember the Cuban Missile Crisis of 1962 - I was just shy of 7 years old.) I do remember ‘Duck and Cover’ drills at school. ( 1 ) Partially because of growing up in Scouting, the concept of ‘be prepared’ has been a cornerstone for me. Being a member of the Canadian Reserves in my teens, just post Viet Nam, I was painfully aware of what might happen ‘If the Balloon goes Up’. ‘Grab and GO!’ became the concept : to quote Robert Heinlein, ‘The best way to avoid being killed by an atomic bomb - is not being in a city when the bombs fall’. ( 2 ) I have been a low level ‘Survivalist’ since way back. (I still keep a simple ‘Go Kit’ in the truck, these days mainly out of habit.) To temper this all however, my life’s experience has also proved ‘the disaster you prepare for is never the disaster you get’. So this has resulted in a kind of ‘Prepare it, Pack it, Forget it’ kind of method.

I have lived almost my entire life ‘below the poverty level’. My mom had been born in the early 1930’s into a working class family, with deep ties to dirt farming in the extended relations. So from both, came principles like ‘a penny saved is a penny earned’ and ’work for it before you buy it’. I was 12 when my father abandoned the family, leaving my mother to raise 5 boys on her own. (Almost unheard of for a ‘middle class’ family in those days.) I grew up on what was called ‘Social Assistance’ back in those days. ‘Making Do’ and ‘Make it Yourself’ was standard. My mother was an exceptional household manager, and because of this, and through her constant hard work, we avoided many pitfalls of poverty. A line from Stevie Wonder’s ‘Living for the City’ certainly applied ‘…clothes were worn, but never were they dirty’. (3) There are a large set of skills I developed because of all that. Since I became a self employed artisan in 1992 things certainly have not improved much.
I have never felt comfortable if the pantry is not fully stocked with basic food and household supplies. Since moving to Wareham in 1989, this kind of extra storage has proved useful any number of times. Being in Lower Grey County means almost every winter at least two or three periods being snowed in from winter storms over several days. It is also the highest point in Ontario, and wind storms (often unrelated to snow) also result in similar length periods without electricity.
Although perhaps a bit excessive (see previous) the normal situation here is having 4 - 6 weeks of ‘normal’ food level stores. Before hitting the ‘emergency’ stockpiles. (4) On a typical year, my economic situation of the winter months (more like total lack of any income) tends to draw down the normal food stores over January and February.

Alas, Babylon

The week of March 9 - 13 was the tipping point for me. I had been following the developing situation with COVID-19, searching out science based information (W.H.O. / Johns Hopkins). ( 5 )
That week I had made two supply runs. Again the normal here is hitting Bulk Barn about once every three months for largely very basic items like flours, sugar, dried and salted. The last stop there had been early December (mainly Yule baking supplies). Tuesday March 10 I had gotten enough to fill the various bins and jars in the pantry, not really anything out of the standard. If this had not been a normal re-stock, I might have been a bit more thoughtful on a couple of things. Dry baking yeast as one thing (we had one open and one extra already on hand).
As that week progressed, I saw some potential for shortages and crowding coming up with March Break coming. Hand sanitizer had already effectively disappeared over the course of that week.
(Bear in mind here that the WHO would officially announce COVID-19 as a pandemic on Wednesday March 11.) I normally stay away from town or travel when all the ‘Weekenders’ flood into our area for any holiday period as is. So with this in mind I visited our local Foodland in Dundalk (only grocery within a 25 minute drive in any direction), about first opening on Friday morning. For me this really was more or less a ‘heavy two week’ assortment, in practice just filling all the spaces on our shelves. (6)

I got home later in the morning, Friday March 13, as the official cancellations started. No gatherings of more than 50. Schools were starting March Break anyway, but it sounded like re-opening was going to be delayed. At noon I got a call from Kelly, who was in Toronto on the first day of her spring contract at the Ballet. Cancelled. So we arranged for me to pick her up at Brampton GO, about 6 PM. That put us driving north up Highway 10, at what normally would be the end of rush hour. The traffic northbound was as dense as I’ve ever seen it. There was almost nothing coming south, again not normal for the start of March Break, when usually a lot of people are heading into the USA for warmer holiday destinations. The drivers were as erratic as I have ever had to negotiate (I had purposefully driven my much larger Jeep Cherokee, having weathered ‘holiday’ traffic insanity many times in the past.)

- We started our personal self isolation that day, March 13. Since that date, we have only left Wareham unless at least 14 days have passed (this partially to ensure our own infection clean status).  

- On March 25, the Government order was for no groupings over 5 persons - scheduled to April 8 initially. We made a supply trip out on March 26. On this outing, we started alcohol wiping after stops.
- On April 11, Ontario extended that closure order to April 23. We made our third supply run on April 14. On this outing, we started gloves and masks. (7)

Additional : By the time it was clear that this was NOT going to be a short term problem, we switched to even fuller isolation. Supply trips from about June 2020 have been made on a monthly basis, this primarily for food, with any hardware items waiting for those trips. Banking shifted over to either deposit box or electronic.
 

So here we all are…
https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection.html
https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_Canada#March_2020


Grasshoppers

It will not be a surprise to those who know me well that I am a big fan of John Ringo’s writing.
Given what is happening right now, (mid March 2020) with COVID-19, it is hard not to see echoes from two of his stories : ‘Under a Graveyard Sky’ and ‘The Last Centurion’.

The Last Centurion was published in 2008, and is a self contained tale about a unit of the American army, left behind in north Afghanistan as a perfect storm of severe climate change and pandemic sweeps over the planet. ( 8 ) Written in a very Robert H. Heinlein style, a big part of the background Ringo details in the early stet up part of the book concerns the actions of a basically delusional American president, who drifts further and further from reality.  Through this rapidly disintegrating national situation, ‘solutions’ are imposed, these based on a wildly distorted world view. The results are predictably a complete disaster.


Under a Graveyard Sky was published in 2013. This was the first novel in the continuing ‘Black Tide Rising’ series. Here the key plot mechanism is an artificially created plague that combines the transmission methods of influenza with the type of brain modification found in rabies. (Yes - effectively Zombies, but medically produced, not supernatural.) This first book covers the activities of a single (admittedly somewhat exceptional) American family as they navigate an escape from the resulting collapse of the USA. Putting to sea for survival, one of the major situations of the second half of the story are their attempts to find survivors locked down aboard a luxury cruise liner, otherwise filled with the ‘infected’.

As two additional pieces of reading in the ‘End of All Things’ genre, I mention ‘Alas, Babylon’ by Pat Frank (1959) and ‘Lucifer’s Hammer’ by Niven & Pournelle (1979).

Alas, Babylon is most certainly one of the classics, and still remains one of the best looks at collapse and enduring. Most certainly dated, it comes from a time of ‘limited nuclear exchange’ and well before a society dominated by the internet and complex electronics. (available as a free download)

 

* ‘Hunkering Down’
I guess I am officially now ‘some old guy’. I was very surprised recently on the comments that came up on FaceBook (ok!) when someone of my own ‘vintage’ used the term. And a pile of people started on ‘Who talks like that?’, and more significantly (to me) ‘What the heck does that mean?’.
For the millennials reading…

" Hunker Definition: To lower oneself into a squatting position; to hide, remain, or stay low; to get ready to do hard work; to stay firm to one’s principles.
The word hunker is attested from the year 1720 and is of Scottish origin. Where it came from is unclear, although some sources speculate that it might come from a Norse word meaning to crouch down.
Hunker Down - was a south-western US dialect form that was popularized by President Johnson in the mid 1960s "


1 ) Peterborough was considered a ‘third round’ target at that time. Canadian General Electric was the town’s major industry, and was deeply involved in the development of the CANDU reactor system.

2 ) Most likely from ‘Farnham’s Freehold’ - 1964 (Which I would have read for the first time, about 1970)
(available as free download)
Because of being loosely ‘tied in’ during the 1970’s and early 1980’s, I did get a couple of phone calls late at night warning me to ‘Bug Out’ .
https://en.wikipedia.org/wiki/List_of_nuclear_close_calls#1970s_and_1980s

3) Look, I am NOT suggesting my situation in an way compares to the grim reality forced on American Blacks in at the same time (late 1960’s and early 1970’s) as detailed in this song. But in the place and time I grew up, I certainly experienced the ragged edges.

4 ) Admittedly, much of the ‘disaster’ stores are pretty grim. Some of that stuff is in ‘little green cans’ dating back to the mid 1970’s! Boil in the bag camping meals. Some dehydrated foods, packed in cans, sealed in nitrogen (remnants of those paranoid years - that stuff will last forever). Bulk dried rice, beans, and even stranger stuff. Things you would never really want to eat, save in an absolute emergency - but that I’ll be happy to have, if it really ‘hit the fan’.
Note : Read the military experience? Training and supporting ‘equipment’ to ensure personal security is also on hand. Just in case anyone reading thinks attempting to rip me off is a good idea.

5 ) My first repeating of science based information (as reposted on to Facebook) :
- March 2 : Johns Hopkins : “Coronavirus Disease 2019 vs. the Flue
- March 9 : World Health Organization : "Q&A on coronaviruses (COVID-19)" (often revised)
- Starting about March 10, daily reading at CBC
- March 19 : ARCGIS : “Canadian Outbreak at a Glance” (real time revisions)

6) One of the humorous things here was toilet paper. It had been on sale for half price back on the previous grocery trip, about March 1. So I picked up two large packages back then. Neither of which would end up broached until considerably later, by the way. I heard from a neighbour who was into Dundalk on Sunday March 15 that over the two intervening days, the shelves had been cleared.
Our own use rate, two middle aged adults? One pack of 12 over the month of March 13 to April 14.

At the time, one of the things I certainly noted was that there was no similar run on 'feminine hygiene products' - which certainly suggested to me just who had been doing the panic buying.

7) It should be no real surprise that as artisan makers, both Kelly and I keep both disposable gloves and simple face masks in our workshops. Gloves for working with paints, solvents and acids. Masks mainly for dust (some wood dusts are toxic). Safety glasses and face shields obviously. Plus more heavy duty protective gear for working with more dangerous chemicals sometimes needed in our work.
See end of note # 4.

8 ) One of the important elements Ringo (correctly) introduces is the concept of ‘tipping points’. Not necessarily long slow incremental environmental changes, but more realistically a series of sudden and drastic weather events.
One of the huge ‘differences of opinion’ I have with Ringo’s underlying set up for the novel is his very definitely stated view that global warming is not in fact happening, and that human effect CO2 was in fact *delaying* a natural, and major, global cooling effect. His plot has plague reducing human activity, reduced activity stopping a cushioning effect, so the climate suddenly drops into another ‘Little Ice Age’
Wrong. Look out the window.
This hardly is the experiment we all wanted to run. But the current economic stoppage from COVID-19 isolation is forcing us to undertake the experiment. Hopefully someone is keeping records?


Addition - September 2021

On Privilege (a bit of a rant)

It has pointed out to me, many times over the period since March 2020, that I am somehow 'Privileged'.  In this, people are referencing the fact that I own my own home, that I live in the country, that I have stockpiled resources, that I have certain life skills. They so clearly are NOT referencing race or sex (and it most clearly can not be economics!)

Remember 'Be Prepared' ?

Yes, I am not living in a 15th story two bedroom apartment, with three kids, in downtown Toronto, working some MacJob. 

No one GAVE me my current situation. 

I. EARNED. THIS.

The first actual *vacation* I have ever had in my entire adult life was in February of 2019. I was 64 years old, and had been working constantly, full time, since 1979. Yes - I have had various working trips, where the projects themselves covered the travel costs involved. Yes, I got a travel grant in 2016 to go to Europe and Scotland - where I worked on a total of FOUR different projects.

I never owned an automobile before I was in my mid 30's. I have NEVER owned a vehicle less than 10 year old. I drive them until they get too broken to fix.

I 'shop at the dump'. Regularly. When do buy anything (outside of Wareham Forge supplies) I almost always buy at second hand stores. Even with groceries, a huge amount is 'short dated' mark down. Almost all my electronics are a decade old (or older).

By the time I was thirty, I had saved enough for a down payment on a house. A four room house at 450 square feet (so the size of a one bedroom apartment) on an equally tiny lot. When it was sold 4 1/2 years later, in preparation to purchasing at Wareham, it was the lowest priced house sale in Toronto that year. I managed to clear my mortgage for the property at Wareham in 2019 - after 30 years. 

Is being smart a Privilege?

Is being careful a Privilege?

Is being resourceful a Privilege?

Is working hard a Privilege?



Monday, September 20, 2021

Replacements and Improvements - Smelter Air systems

The September iron smelt proved problematic on several levels.

 

 The first contributing problem was the set up of the furnace, with the tuyere point set right above the extraction arch. This arrangement was dictated by the physical layout of the Hals sod cone build. Our normal build is to place the tuyere point at 90 degrees to the extraction arch. This places the air system well out of the way of the working area during extraction.

Air System in place at smelt start.

To provide clearance for the expected slag control steps, the pipe fittings used to conduct air to the tuyere were hung via chain off a metal bar, supported by a pair of uprights placed well to the sides of the gap in the sod structure. In addition to this long used element, a new section of plastic pipe had been added. This was for the introduction of a new air volume meter acquired by team second Neil Peterson.

 

The second thing was the level of damage after the first smelt in June. With a bottom extraction, especially given the thinner than our standard walls (at 4.5 cm), certainly a certain amount of breakage was expected. 

The bloom created was also much larger than expected, at almost 9 kg. As the mass was fairly spongy, that weight does include more slag than has been typical, but this actually increased the raw size of the mass that was pulled clear.

Then the 8 inch snapping turtle crawled in overnight, and broke away about a third of the front wall surface. 

The culprit, red line shows were piece seen to right was broken away
 

The Icelandic clay mix was expected to suffer more heat effects than our standard use of high fire EPK clay, and this certainly proved the case. There had been considerable erosion around the normal hot spot around the tuyere point. The original wall thickness reduced to as little as 1 cm at the location directly above the tuyere. (This can been seen in the lower wall section broken free by the turtle, laying to the bottom right in the image above.)

Furnace before start of repairs in August

In preparation for the Phase 3-B smelt, The lower section of the front of the furnace had to be significantly re-built. The extraction arch was framed up using the same side blocks and lintel piece as before. The area above this was built up of new clay mix. Another layer of clay was plastered over the eroded areas on the inside. 

The end result of all this was that there was a failure along the line between the fresh clay and the original wall surface (not entirely unexpected). Although certainly this did not prevent the full smelting cycle to proceed effectively, it did mean there was a major weakness along the edges seen above. 


The third thing was worker experience. It was decided (number of contributing factors) to let Rey Cogswell undertake the extraction. Although Rey had certainly observed the process several times, and assisted directly in the process at the June smelt, this would be Rey's first full attempt at an extraction. Understandably, Rey was tentative when working against the extreme temperatures and still uncertain about exactly how to manipulate the slag bowl to break the bloom free. Taken altogether, the work was not undertaken quickly enough, and the entire slag bowl and bloom complex had started to cool down. To be fair, the bloom was again high yield and spongy, meaning another excessively large mass.

Damage to the front of the furnace, right after extraction

This combination would result in breaking away the entire front bottom half of the furnace, pulling the tuyere and air system totally free, but still hanging from the supporting bar. There would also be a large fan of hot slag, furnace wall fragments and still burning charcoal pulled out of the furnace and into the slot in the sod structure. In the (normal!) haste to get the bloom mass over to the stump for the initial compaction hammering, this left the air system connections exposed to the concentrated heat from this debris.


Which is a long explanation of why it proved necessary to replace a number individual pieces of the long standing air system.

The fittings have long been 1 1/4 inch ID threaded pipe. This has allowed for simple modifications to the basic T format, with various different fittings available for the downstream end, to mate with the different tuyeres that have been used. Opposite this is a fitting that can quickly be unscrewed to allow for probing down the inside of the tuerye to clear any blocking slag. The original view port was a simple plexi disk, sealed on to the end of this fitting. (One of the casualties was this plexi, admittedly getting pretty scratched up from 15 + years of use.)


Tuyere to Port at bottom, air flow / pressure at left, pipe connects at right

Larger viewing glass towards air pipe diameter.

I had picked up a number of thick glass disks (from projector units) a number of years ago, each a bit over 2 1/2 inches in diameter. With a lot of picking and matching, I was able to get component pieces of plumbing fittings at my local hardware that let me mate up the glass disk to the air supply T. The result does include one rubber section and one plastic. In use to clear blockages with the customary 3/8 diameter rod, the whole end unit would screw free from the short double threaded section seen directly attached to the T connector above.

I also made up replacements for mounting either the straight section required for the probe of the new air flow gauge, or to include the nipple for the (older) air pressure meter. Either these, or the short double threaded pipe would be at right angles to to the tuyere / port combination. I was recently able to get a roughly 6 foot section of flexible solid metal piping (normally used to duct auto exhaust at repair shops) - Thanks to my old friend Lloyd Johnston. This pipe is about 3 inches ID, so the additional element allows a flexible coupling to a plastic piece that will fit nicely down the interior of that metal pipe. (One serious advantage, beyond durability, is that this metal pipe has a relatively smooth interior, and does not create the loud whistling noise from the corrugated plastic tubes in use up to recently!)

Blower side elements : sliding blast gate / Y to attach a second air supply.

 One of the major experimental elements to undertake is getting much more accurate data on both air volumes and pressures, not only for our standard high capacity electric blower, but also for the various human powered bellows used in the past. As detailed in an earlier posting : Mind the Blast the measurements recorded up to now should be at best considered approximate. The new flow gauge is capable of both measuring, and recording (via computer) extremely detailed data, over the progress of an entire smelt, minute by minute.

It would be quite valuable to our understanding of the dynamics with various human powered systems to also be able to generate comparison numbers. The main problem with this is not in instrumentation, but in the raw labour required to work an entire smelt (four to six hours!) using bellows. To that problem, I made up an additional element, which can be screwed in place downstream of the normal sliding plate air control. This has a one way (sump pump back flow) valve. Although not tested yet, the hope is that with this element in place, the bellows can be utilized for short periods, by using the blast gate to seal output from the electric blower. The one way valve should effectively seal air from the blower escaping through the bellows side when the blower is powering the air supply. 

 

My hope is to undertake at least one of these bellows comparison and recording tests for the next upcoming smelt...

Saturday, September 18, 2021

Sod vs Turf?

I've never been to Iceland.

(Although at least my primary smelting partner, Neil Peterson, has.)

One of the important materials for the Viking Age iron furnaces at Hals, Iceland, is the use of cut ground cover - 'turf' for the structure of the furnace.


Of course after 1000 years and with only an field report to base measurements on, exact details are hard to determine. The original report had the excavation diagrams as quite small scale, and only in grey scale. The text describes the turf blocks seen in the cross section cut along the edge of furnace shaft III as being about 10 cm thick. (1) Recently Kevin Smith had provided us with larger sized versions, also in colour and with a more complete key to the elements represented (2). The version seen above has been modified and printed to graph paper (seen lightly in the scan) at one square at roughly 10 cm. The lower diagram is my own interpretation of how that furnace would have been originally constructed. More or less taking the line of the shaft, and pushing it back to vertical, shifting the individual turf strips against this line. (This would be the guide for the construction of the furnace used for the June 20 and September 4 tests.)
 
One of the certain problems with attempting to design any experimental archaeology project is always 'how close can you get'. Our long standing work related to Hals (since 2007 / now 10 smelts) has included many elements which may be at best approximations :
- use of DD1 (Fe2O3 / red oxide) ore analog : not natural bog (FeO-OH) ore
- (most recently) simulated clay mix : not local Icelandic clay
- stones of Ontario granite or gniess : not Icelandic basalt
- sand of Ontario granite origin : not from Icelandic basalt
- charcoal of either white oak or hard maple ; not Icelandic birch 
- local Wareham cut grass sod : not natural Icelandic turf

In recent discussions, the question of terminology over this last aspect arose. It is obvious that that environmental conditions around West Central Iceland at Hals would be significantly different than those at Wareham, in Central Ontario. Growth cycles are not comparable, as well as the types of natural vegetation. This is compounded by the fact that the yard at Wareham was started as an artificially laid course of commercial grass sod, laid over a new graded surface about 35 years ago. This has been left largely untended, so whatever natural plants growing locally have slowly encroached. One specific change has been the dominance of 'twitch grass' in many areas, which chokes out other plants (itself an invasive species). 
 
June furnace, before start of August repair.

 
The overall result is that any cut blocks of the upper grass layer are more dirt than root mass. This is important related back to use of this local grass sod for furnace construction. The roots are what holds the dirt in place, securing the structure.  When this organic material is exposed to the heat of a working furnace, the roots simply burn away. The now hot dirt quickly looses any structure, and will fall apart and flow almost like water. Eventually, and especially if exposed to full temperature furnace gasses (at the range of 1150 - 1250 C), the silica components of the dirt can fuse into a fragile mass.  
In the image above, taken the day after the first full smelt of that furnace, you can clearly see the failure of the inner edges of the stacked grass sods, where heat had penetrated through the relatively thin (4.5 cm) inner clay liner.

I wondered how I might detail what I see as a major difference between the Ontario (semi wild) grass sods cut here at Wareham, to the Icelandic turf used at Hals. 

I still had a couple of pieces of the sod I had cut for use in the June build left over. 
From this I cut a block, as close as I could manage, at 20 x 20 cm, trimmed to 10 cm thick. The precise measurements are 20 x 19 cm, thickness tapers slightly from 11 to 10 cm. I used hand shears to trim the grass fairly close to the ground surface. 
 
Cut block : 3/4 view
 
View of the front edge


The weight of this block, as damp and 'living' is roughly 5 kg (5093 gms including the metal tray it is sitting on)

The intent here is to leave this block exposed to the sun for a length of time to start to remove the contained water. 

- Next the piece will be heated (likely by placing the tray on the top surface of my wood stove) to remove any final moisture. 

- At this point the material will be weighed again (so giving some idea of the water weight).

- When the block is 'bone dry', it should be possible to knock off the dirt from the root mass. This will allow for photographing the root web, and most importantly weighing just the contained dirt for comparison back to the starting amount. 

This all should allow for some kind of comparison 'root to dirt' measurement. 

This exercise is more likely to be only of qualitative (rather than precise quantitative) value. The hope is that this test might proved some data towards what up to now has been a gap in my personal experience with Icelandic conditions. 


1) Smith, K.P., 2005, "Ore, Fire, Hammer, Sickle: Iron Production in Viking Age and Early Medieval Iceland", AVISTA Studies in the History of Medieval Technology, Science, and Art, Volume 4, USA

Also available as PDF on line : https://www.academia.edu/191535/Ore_Fire_Hammer_Sickle_Iron_Production_in_Viking_Age_and_Early_Medieval_Iceland

2) A overview of both the Hals site and these experiments is currently under preparation, co authored by Smith, Markewitz and Peterson (‘Now with 70% Less Clay! Experiments with Viking Age Icelandic Turf walled Iron Smelting Furnaces’) A short video overview was presented at the recent EAC 12 virtual conference, available on line : https://youtu.be/7Ltz5NG2BP0




Wednesday, September 08, 2021

Mind the BLAST

Correcting Reported Air Volumes


    One of the critical elements in any bloomery iron smelt is the amount of air provided to the furnace. Air, or more specifically the oxygen component, supports the burning of charcoal, so the production of both heat and reactive gases. In simplest terms:

O2 (air) + C (charcoal) = CO (heat) 

CO + Fe2O3 (ore) = CO2 and Fe (bloom)

    The mechanics of the air blast itself is a lot more complicated than just the chemical equation. Air volume effects the size of the burning zone, delivered pressure how far the burn zone penetrates into the furnace, and entry angle of the blast determines how the burning zone is positioned within the diameter of the furnace. ( see ‘About the Air’, blog post May 23, 2013 )


    Most working teams actually don’t concern themselves with recording air volumes, as a much more practical measurement is how air blast effects charcoal burn rates. Over the course of a working smelt, knowing just how long it takes to consume a fixed measure of charcoal is one of the best indications of what is happening inside the furnace. Over past experiments, recording the addition times of fixed measures of charcoal has been a standard method of indicating shifting burn rates within each experiment. This instead of mathematically generating an average (total time against total charcoal consumed), a method commonly used by other teams.
    Directly related to this, most other teams have one standard air production method, either repeated use of the same electric blower or human powered bellows. With any bellows equipment, obviously the greatest variation in delivered volume and pressure, minute by minute over the course of the long smelt effort, will
be through the differing activities of individual (changing!) bellows operators.

The long series of experimental smelts recorded here have seen a large number of quite different air equipment used, even when considering those used on multiple tests :

Vacuum cleaner blowers - two different
Norse blacksmith bellows - two different
Norse ‘smelting’ bellows - three different
‘Compression’ blower - the commonly used standard (seen below)


Partially because of this wide variation in air equipment, there was an attempt made fairly early in our working series to at least roughly measure air volumes produced.

Current wind speed gauge, about life sized
 

    It has been mentioned numerous times, those working without Institutional support often can only provide the simplest of measuring instruments. I had investigated possible methods of measuring air volumes back in 2007, and what proved feasible was the purchase of a simple wind speed anemometer, a type used by sailors and wind surfers. The precision of this unit was low, and in retrospect, the durability of construction is likely to have further effected even that level of accuracy over time. With the gauge set in line, measurements would be recorded as a rough estimated average while observing for several seconds, as Kilometers per Hour. The  KpH number combined with the pass through area (2.5 cm diameter) and a calculation made to convert to Litres per Minute. This was never considered more that accurate to within 25 LpM at best. Additionally, from the vary start it was recognized that any measurements from these methods could only be considered roughly approximate.

High capacity electric blower - US Navy surplus

Set up of wind speed and pressure gauges, April 2008 (smelt 32 - D14). 

    Along with a 'box' fitting to hold the wind gauge, an additional fitting can be added to allow inclusion of a simple pressure gauge. This set up was used infrequently between separate smelts, plus only recorded irregularly during an individual experiment.
    Air volume from the most commonly used industrial blower was controlled using a sliding plate styled ‘blast gate’. This had been marked with a set of lines roughly calibrated to 100 LpM amounts, determined as indicated above. Out of concern of the wear being caused by the high output speed of this blower, most frequently these marks would be used to record air volumes, not repeated use of the wind speed gauge (which was only left installed for the measurements).

    Given the duplication of method, it should be considered that the air volume numbers recorded over those smelts using these systems should at best be considered ‘relative’, as a high level of variation in precision was certainly to be expected. One major reason for continuing with these methods, despite the known lack of accuracy, was to be able to make some estimation of the functional air delivery from the various human powered bellows equipments used. It was quickly observed that any theoretical volumes as calculated via dimensional measurements, were quite different than the actual working volumes produced. There was also considerable variations between individual operators, and even the same operator over even a short working cycle. (Further information on this can be found as ‘Air Delivery Test’ - October 2007 )


    Neil Peterson had acquired a new, and significantly more accurate, air volume meter - the HHF1000 by Omega, which was available for the smelt on September 4, 2021. This instrument uses a small sensor that is positioned through a 6 mm diameter hole into a pipe section, with both direct digital read out and even the ability to wirelessly transmit data to a near-by computer. It makes readings down to every 1/4 second, with an expected accuracy of 1.5 %. Needless to say the addition of this significantly higher quality instrument can be expected to seriously improve accuracy of measurements into the future.

Over this experiment, four separate measurements were made using the new instrument. This was done roughly each time air flow was changed, that done using the simple marks on the sliding plate of the blast gate. Changes were made because of variations in burn rate or other observations of how the furnace was performing. The meter measurements were taken inside a 40 mm pipe section, the rough multiplier from meter reading to LpM is X 75. Note how there are clear gaps in the recorded measurements :

TimeEventPlateMeterCalculated
10:11   fill rough charcoal     
700    

10:15air increase
(900)

11:19full graded charcoal

11.5    865
11:23air reduced
700(no record)    
550
12:00air increased
8008.8660
12:44air increased
9009.6720

    What is significant to remember is that the plate marks are ‘hole size’ only (so a maximum amount available). There can be considerable changes in flow into the furnace as conditions inside change (charcoal size, any ‘draw’ effect as stack ignites, formation and position of slag bowl, amount of ore contained in the upper stack - all come to mind at the least). The meter is measuring the actual air flow at the time point indicated, so differences at similar plate marks should be expected. This is clearly seen even with this limited set, in the differences between the two measurements with the plate setting at 900 LpM, early with the furnace full of rough ‘out of the bag’ sized pieces compared to later in the smelt, with smaller gaps between graded charcoal, plus the addition of about 3 kg + of combined ore / slag pieces within the stack.
    Clearly this limited set of measurements is at best a ‘proof of concept’, definitely not enough data to draw conclusions of the operating changes within the air / furnace system over the duration of a complete smelt!

    Comparing the plate marks back to the volumes calculated from the meter readings shows an error factor of roughly plus times 1.25 (how much larger the plate mark is than the meter calculation). Although there will be some shifting of potential accuracy between the earliest wind speed gauge readings and the more recent (due to wear in the vane shaft), certainly this set suggests all the earlier numbers will be 20 - 25% higher than what was actually being involved at those times.


    Obviously, an important set of observations can be gathered by leaving the new instrument in place over an entire smelt series (or at least taking measurements over a short set of time points overall). Although the pressure gauge now on hand is both an analog and far less precision unit, recording variations in delivery pressure will also provide some insights.
    One important set of measurements employing this new gauge will be to undertake at least some of the air delivery from the next smelt using the current V3 Norse styled smelting bellows. At best, the current estimates for air delivery using this air system are based on measurements made using the earlier wind speed gauge as described above.


Thursday, September 02, 2021

30 That Never Sold - 'Wind Widgets'

 The last couple of years I exhibited at Summerfolk in Owen Sound, I mounted a series of work based on the Four Elements : Earth / Air / Fire / (Water).

I never completed the last element, work based on water. This largely because of repeated trips to Scotland and Europe after 2014, to participate in bloomery iron research projects, all over that same part of later August. 


For the 2013 year, the theme at Summerfolk was AIR.

In an attempt to have a body of lower priced objects, that I thought suitable and of interest to a Folk Festival audience, I had created several styles of individually made 'Wind Widget' outdoor spinners. These were all made of durable metal, unlike the slightly cheaper plastic spinners becoming available about the same time. There were two broad groupings, either made of solid copper or brass, plus those made of aluminum or stainless steel. Some of the curved aluminum ones were spray painted  with merging bright colours.

The more expensive (considerably!) material copper and brass were priced $20 (taxes included). The aluminum and stainless were priced at $16 (taxes in)

I don't think I sold one...


I still have over 30 of these. I personally think they are good objects. The spirals and mobius strip types are roughly 8 - 10 inches in diameter, the strip versions about 18 inches long. With the light weight against the curving surfaces, they all are quite mobile to the wind. They certainly are extremely durable - I've had some of the first prototypes for these hanging outside at Wareham, year round, for a decade.


And no - I've never been able to 'Understand the Marketplace'.


Tuesday, August 31, 2021

36 seen at Wareham

Walking through Wareham
the Yard Art Tour

So here's the thing.
I've now been in Wareham over 30 years - also the length of time as the Wareham Forge.
Over that long a time, you tend to accumulate a lot of pieces.
Some of these are concept tests and samples that lead to major commissions.
Some of these are good pieces, that for one reason or another just never attracted a buyer.
Some of these were intended as 'show' pieces, which simply got marred after being repeatedly being hauled and exhibited.
Some of these are 'just because' pieces, using novel techniques or conceptual designs that cried out to be created.

Many are often what any artist considers some of their best work.


For an overview of what is mounted up around the yard :
Go on to the Yard Art Tour

 

For those who are wondering why contributions have been thin of late?
I've experienced a medical, an am pretty much limited to 'one hand hunt and peck' on the keyboard right now.

Saturday, August 07, 2021

Setting up for Phase 3 - B

 Those who have been following the recent work have seen a number of commentaries related to the ongoing series of bloomery iron smelts based on elements from the excavations at Hals, Iceland, by Kevin P. Smith. 

The basic undertaking for the phase three experimental series was build a potential Hals type turf / sod furnace, containing a relatively thin clay liner, using a mixture simulating (as best possible) the material found close by that location. The full build was done in mid June, with the first complete firing cycle on June 20. The intent was to subject the furnace to multiple firings, including one after a winter exposure to freeze and thaw.

After the first use of the furnace, there was pretty much the normal expected damage to the front section of the furnace, with erosion of the walls around the tuyere, and breakage at the extraction arch.


Furnace - just at end of the smelt
20 cm turtle - and damage

What was not expected was the invasion of the warm furnace by a large snapping turtle, which resulted in a large section of the front wall section breaking clear. Weather at Wareham has been unusually wet over later June, July and now into August. (This normally a period where there is little or no rainfall = Climate Change!). Although the top of the furnace was fitted with a metal cover, there has been considerable damage to the 'baked mud' outer sections of the furnace walls, plus considerable slumping to the original grass sod surrounding structure. 

Field drawing of the furnace - August 7, 2021
Note combination of metric and US Imperial units (single marked tape!)




Typically, the next scheduled smelt attempt would take place over Canadian Thanksgiving, this being October 10. I have some concern over additional damage to the existing furnace structure, so have decided to undertake the required repairs to the lower front of the furnace, including breaking clear the internal slag bowl which was left in place after the first smelt.

Interior - just after smelt
(tuyere still in place - at top)

Roughly same view, slag bowl broken clear

 The slag bowl from the June smelt did nicely resemble those exposed at Hals, a distinctive C shape with a cupped cross section, the front edge broken away where the bloom had been pulled free during the front extraction. The remaining slag broke free of the interior wall surface quite easily, using a chisel tipped bar from above. There was little actual damage to the wall structure from this process. 

Condition of furnace - August 7

As seen in the images and drawings above, a considerable part of the front wall surface had been broken away. 

The original line of the sods can be distinguished as the place where the upper exterior wall changes from smooth to a wrinkled texture. That top area, about 10 cm wide, despite the cover, had been flaking away in the rains. The slumping of the sod structure is obvious here as well. The heat from the smelt had largely destroyed the binding root structure, leaving basically baked earth. Again the rains were slowly washing this earth down and away. 

The original build had constructed a full cylinder of clay, with the stones supporting the arch and tuyere placed to the outside. As a result, there was no exposure of the stones to heat, other than the short time of extraction. The archaeology at Hals indicates fire marked and slag adhering stones. For this reason, in the repair, a set of small flat stones were used to block in the eventual extraction arch, which will expose the inner surfaces to the heat of the lower furnace.

Interior after repair. Dark grey is the new clay added
Lower section, replaced lintel stone with small flat stones filling extraction arch

In the initial build, it proved quite easy to keep the wall thickness to 4.5 cm overall. This simply was not possible when adding new clay to repair sections considered badly eroded, and those locations where the walls needed to be replaced entirely. new material had to be added by reaching up inside through the extraction arch, most often working from touch alone. There are certain to be places where the fresh clay will be much thicker. Additional clay had to be added around the edges of the small flat stones used to seal the extraction arch, as these where chosen from a random pile of available (gniess) pieces. The same granite lintel stone was used as in the first build, only this time it's inner surface will be exposed to the full heat at tuyere point. Once again, this slab serves to support the upper layers of grass sod (total of three).

Finished repair build, tuyere yet to be installed


An extra row of grass sod was placed around the furnace liner, building the supporting structure back to approximately the same level as at the start of the first smelt ( about 65 cm above hard base). Extra dirt was placed in a ring around the top of the sods, with the hope of reducing any fire damage during the next firing. One additional aspect seen in this image is that the grass composing the sods laid in mid June has continued to grow, and least around the edges of the sod cone. 

For this repair, a total of five prepared balls of the clay / sand / manure mix were required, each about the size of a large grapefruit. (This material left over from the initial construction of the clay liner.)

Depending on team availability and other ongoing work here at the Wareham Forge, the hope is to undertake the next smelt in this series some point over the next two weeks...

Sunday, July 18, 2021

You mean ONLY with more air?

 Warning : Often when you e-mail me a question, I tend to ramble on at length in reply. Having spent the time (for me typically an hour or more) on an attempt at a full consideration of that question, I will turn the reply into a blog post as well.


1) so you've shown the early medieval iron bloomery furnaces only produce accurate blooms when you push more air in than you can currently manage using what you think was the bellows technology of the time?

 

 What a ball of wax that is! 

I consider the effect of air a big disconnect, especially with what has happened here in North America as interest in bloomery iron making developed.
I consider myself one of the extremely small group that started the whole thing, in the early 2000's. Lee Sauder and Skip Williams are most certainly the very first to seriously undertake and repeat the process, and finally come up with a system that not only produced significant blooms, but consistently. Their objective was not historic method, but functional results - how to get the best yields at the highest density. Modern electric blowers were employed from the start. One very important difference between North America and Europe is over here work with bloomery furnaces has been primarily in the hands of blacksmiths - not archaeologists or re-enactors. Lee's original point of inspiration was African systems, for which there was some 'traditional' recording still available. He would return to this interest into the later 2010's.

Making bloomery iron is an elaborate, expensive, time consuming, and labour intensive process - with a very steep learning curve to positive results. So the resulting metal has a high 'investment' value. Lee has set the 'selling price' of his bloom pieces at roughly $60 CDN / kg (the few times I have been asked, I quote $100 / kg). This is roughly ten times the cost of modern alloy steel bars. So for blacksmiths, the only object type that can justify this kind of investment in materials to object price is knives. Unfortunately, here in North America, this has lead the entire Early Iron movement to become dominated by bladesmiths. This in turn has lead to what I feel is a quite unrealistic obsession with carbon content, an extremely modern consideration of what is clearly a 'pre industrial age' material (and processes).

The 'Gange o Fer' in 2004 : (L-R) Lee Sauder, Skip Williams, me, Mike McCarthy


My interest started with Viking Age systems, most specifically sparked by the single smelt event at Vinland by the Norse. c 1000 AD. As part of the original 'Gange o Fer', it was so clear that there were many individual variables effecting the dynamic inside a small scale furnace. So the early years were simply testing variable after variable, in the hopes of getting some understanding (and control?) over these both individually and in combination. So my focus has never been either to best possible yields or specifically 'quality'. If anything, my estimate of 'good iron' is based on the ease of compacting the bloom to bar, then the ability of that bar to be easily forged to object. Yes, we do end up with some blooms to bars being higher carbon, and set these aside (as the Norse would have) for cutting edges.
Through almost all of our experimental work, we have quite deliberately aimed to making smaller blooms, in the 3 - 5 kg range. (Yield % climbs sharply with larger ore volume additions!)

In Europe, much of the work with bloomery iron is in the hands of living history sites and hobby re-enactors. What has been so frustrating to me is the lack of recording. (See my piece in EXARC : 'Standardized Reporting...'). Lee has pointed out to me many times the overall difficulty of getting any kind of effective measurements of air volumes, and that the only uniform field reporting can be 'time of consumption'. Even there, it is obvious to me that most people are actually reporting total charcoal consumed / total time of smelt. This is actually only a vague average at best.

One one major problem is the simple lack of historical accuracy I see. If you are using what is at best a Late Medieval double chamber bellows (to chambers stacked on top each other) you are NOT using 'Viking Age' method. Too often I see smelts described as 'Viking', which are using different furnace builds and ore types, than the known Norse archaeology. *


Our 'Econo Norse' teaching furnace : Brick, pipe tuyere, vacuum blower, using taconite. The only thing 'Viking Age' is the furnace diameter?

Don't miss understand - people are most certainly getting iron blooms

The times we have used a proven furnace layout and standard ore, yet with variations of a Viking Age type twin chamber (side by side) bellows, consistently our yields drop about 10 % overall, from an expected 20 - 25 % down to closer to 12 - 18 % return. The blooms also tend to be considerably less dense (so harder to work into bars, with more loss at this stage of the overall process). 

Early twin bellows for smelting ? : 'Ubber-Bellows' for CanIRON V prep, 2005


- Obviously, one clear possibility is that the whole furnace layout and overall method we are using is just not effective, and so may be entirely different than historic process. (This might also be a simple as 'we still are screwing up'!)
- We are working with an Fe2O3 based ore analog at typically about 55% Fe content. Natural primary bog iron ore is actually FeO-OH, which potentially could be as much as 63% Fe. Natural ores vary considerably, even from the same location, but the difference between both chemistry and especially iron content may be a significant difference?
- We have certainly found a considerable 'learning curve' with use of human powered air. It may be that we are just not working correctly with this entirely. (One experiment using a secondary collection bladder may be suggestive, but there is nothing from archaeology to suggest this method. Latter Medieval illustrations which do show bellows use, don't show bladders. )


Norse 'blacksmith' size bellows linked to a bladder : SCA 50 event 2015


So key to this whole thing is a more correct statement :
 'We don't get historic blooms when we use Viking Age suggested bellows.'
- There is not much data available on the actual measured density of the existing artifact blooms.
- Others are certainly getting iron - but there is often no clear reporting of actual yield or most importantly the quality of those blooms. 


* What REALLY aggravates me is a most recent trend to individuals who are using 'Viking Age!' as a mere marketing label.

 

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

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