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Thursday, December 1, 2011

October Bead Experiments

On a miserable rainy weekend in Mid October the bead folks got together to run more furnaces to collect additional temperatures and make more beads.

The full report can be found at http://www.darkcompany.ca/beads/bead1011/

Interesting items in this report:
  • Temperatures were taken both inside and in the chimney at the same time for all three furnaces
  • After the day was done the furnaces were broken down and the impact of the heat was recorded at many locations in the construction
  • Some interesting beads were made
  • Some interesting reticella was made

Now we just have a paper to write for ExArc





Friday, November 25, 2011

Bill Short on Norse Weapons & Combat

Our 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:
http://www.hurstwic.org/history/articles/manufacturing/text/arms.htm
and in the turfhouse article:
http://www.hurstwic.org/history/articles/daily_living/text/Turf_Houses.htm


www.hurstwic.org
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 17, 2011

More Bead Experiments

On Sept 10th the bead folks met again to make some beads and continue our research into the construction and use of the viking era furnaces.

In this case we were after data on how warm the furnaces got and how long they stayed at temperature. Peak temperatures around 1200 C were recorded and times in a useful temperature range ranged up to 10 minutes.

The full report can be found at
http://www.darkcompany.ca/beads/bead0911/



Saturday, October 29, 2011

Monday, October 24, 2011

Measuring the HEAT...

Iron Smelting Furnace Temperatures
Short Shaft over Slag Pit

October 9, 2011 / DARC Smelt Team, Neil Peterson recording

On our last smelt, we set up to record furnace temperatures over the duration of the experiment.


The furnace was our standard short shaft type, roughly 25 cm interior diameter, 70 cm total height.
Walls were clay and straw cobb, about 10 cm thickness.
Fuel was hardwood charcoal (mainly oak) graded to .5 through 2.5 cm diameters.
Air volume via the tuyere (set at 20 cm above base) was roughly 800 litres per minute.

Holes were drilled through the furnace walls at roughly every 10 cm, starting at 10 cm above the interior base.
Measurements were taken using an industrial quality digital pyrometer (Model HH12B from Omega with type K bare wire thermocouples).
The probes were inserted roughly 5 cm beyond the interior surface of the furnace wall.
Measurements were taken roughly every hour over the course of the smelt event.

Because the probes did not reach into the central core of the furnace, there is every possibility that the central furnace temperatures were even higher than what was recorded.
Our thermocouples failed (melted!) at roughly 1350 C. On several recordings, this temperature was reached.

Image : Neil takes readings, early in the smelt

Time Elapsedbasetuyereplus 10plus 20plus 30plus 40top


10 cm20 cm30 cm40 cm50 cm60 cm70 cm
12:06:06
653890749579343
13:051:05
10421335130011451002610
13:501:503281051plus 1350119511891014660
15:123:1299512261268129311281011608
16:324:32

11241265 *909700719

Note: It has been suggested by some theoretical researchers that temperatures above 1200 C are impossible to achieve inside a charcoal fired furnace...

Cross posted from Hammered Out Bits

Friday, October 21, 2011

Thanksgiving Smelt - fast overview

'Celtic Iron Age' slag pit furnace
October 9, 2011
DARC smelt team
(Darrell / Neil / Marcus)


Showing the initial layout of the 'pit'. A standard 20 L plastic pail was surrounded by dirt, then filled to top with cut willow branches (about 0.5 - 1 cm diameter). Use of concrete blocks would allow for easy excavation after the experiment.


Our standard short shaft furnace is constructed on top of the pit. Clay with straw cobb, 25 cm ID, 70 cm tall. Ceramic tube tuyere (2.5 cm ID), electric blower.

Total time : 5 3/4 hours
Total charcoal : 57.5 kg
Total ore : 48 kg



Slag block as excavated (furnace itself was removed in one piece and retained for further use) There was no actual bloom recovered!


A fragment of the slag block, showing how hot slag had dripped down between the sticks, solidified, the heat converting the wood to charcoal. This from the front side of the furnace, indicating lack of iron (pale green colour). Slag to the rear of the furnace was a black iron rich colour.

The purity of the ore was questionable.
There is a chance some iron may exist trapped inside the slag block. A check with a magnet at the usual location (under the tuyere) did not indicate any however.
It is possible that the existing iron rich slag might be recovered, then utilized in a second smelt attempt.

For now we want to retain the slag block itself as a sample.


The extracted slag block. In this shot the tuyere is located to the upper right, directly above the scale vertical line. The colour shift in the slag from the rear to the front of the furnace is easily seen. There is an extra bulge in the slag about at ground level (the clay furnace sat directly on the loose dirt here.


A full report is in the works!
(duplicate from Hammered Out Bits)

Saturday, October 1, 2011

Thanksgiving IRON SMELT at Wareham

One of the traditional iron smelt events at Wareham is over Thanksgiving weekend. This is 'Darrell's Smelt' (originally a sad replacement for Early Iron after that event was dropped). The DARC team normally takes part.

Because Thanksgiving is a family day for many, and because some people get involved with the archery stuff in KW also that weekend, Smelt Day is SUNDAY.

The tentative plan for the weekend will be this:

Saturday - Furnace Build and Open workshop (self directed)
Sunday - Smelt Day
Monday - Evaluate and clean up

Vandy and I will be prepared to welcome guests any time after 9 AM.
The primary working day is SUNDAY, for those intending on a one day trip.
As usual, this is a 'limited open' event - please drop me a post back if you are intending on coming up.

Going into 2012, I want to work towards a new furnace type. I have proposed to Goderich Celtic Festival that I undertake a smelting demo at their event next August. This would be a Celtic Iron Age, slag pit type furnace. The style applies to early Danish and Anglo Saxon as well.
The upper portion of the planned furnace is going to be much like our standard types (short shaft, clay cobb construction). I have a wide number of ore types on hand, and have not determined which I may use. (Likely one of the Virginia rock ores, as I have considerable of those materials.)

Any working advice from our friends in England and Denmark, who have worked with these type of furnaces, would be helpful!

Tuesday, September 27, 2011

Dr Wallace at Western!

Thursday, October 13th - 3:30 pm B&GS 0165

The UWO Northern Research Group presents:

Presenters: Dr. Birgitta Wallace: Viking archaeology at Vinland: a Cooperative Approach to Research

Abstract:    In the popular mind archaeology is associated with structures and the finding of artifacts, but in reality, that is only part of the story. The environment and context of the site are equally important. Modern archaeology is dependent on interdisciplinary studies in a blend of natural sciences and humanities. The role of the archaeologist has become that of coordinator, drawing on whatever branch of knowledge pertains to the project on which he or she is working. The Viking site at L’Anse aux Meadows National Historic Site in northern Newfoundland is an example of how natural sciences, combined with anthropological, folkloristic, historical, literary and linguistic studies, have given new insight into the world of the Vinland sagas and the contacts of the Norse with the New World.
This event is being held at the University of Western Ontario, London.
Venue (appears?) the Biological and Geological Sciences Building

View Larger Map
 
Birgitta is an old friend and sometimes adviser to those of us in DARC  (and my special 'fairy godmother'.)

Tuesday, September 6, 2011

CanIRON 8 Iron Smelt





This is a clip shot at the recent CanIRON 8 demo by Neil, Richard and Dave.

Neil Peterson describing ancient iron and the ore used in the demonstration.

The furnace used is our 'Econo Norse' test / teaching set up, the ore our DD1 analog.
The result was a good soft iron at 5 kg.

The full smelt report is under preparation by Neil.

This is a set of images by OABA's Sean Stoughton
Published in the Iron Trillium

Notice in all this, you don't actually see Ragnar doing any WORK!

Saturday, August 13, 2011

Glass Bead Furnace at Goderich Celtic

Cross posted from Darrell's Hammered Out Bits

As part of my nefarious plans * for the Earth, Air Celtic Festival at Goderich, this year's demonstration was of a Viking Age glass bead making furnace.


Now, this is really the research project of Neil Peterson, fellow member of DARC. Neil has driven the project, and has applied his (considerable) analytical powers to understanding the related archaeological remains. Much of our work has been focused on the remains from Ribe, Denmark. One of the problems is that the actual bead making furnaces are only represented by a number of clay base plates, with none of the upper portions of the furnaces surviving. There are plentiful examples of scrap and waste glass from the making process, as well as a large number of various styles of completed beads. As glass is virtually indestructible, glass beads are a common grave find as well.

My contribution to the beginning of the project was as the 'fire guy', lending my forge experience to the problem of how to construct and operate a charcoal burning glass furnace. It quickly was apparent to me that I needed some direct experience with how glass bead making works! To that end I assembled a basic set of modern lamp working tools and supplies, and made roughly 150 beads - just to get the hang of it.


Neil had made the furnace up a week before and allowed it to air dry. The construction is made of our standard 50 / 50 mix of powdered clay / shredded dry horse manure. The base oval is roughly 30 x 60 cm, and it stands about 30 cm tall. This is the ninth rendition of the basic plan, which at this point is close to an effective layout in terms of heat generation and functional spaces. (For some discussion of alternative designs and functional aspects, see an earlier posting. )

One continuing point of experimentation remains the problem of creating the required temperatures for glass working - and sustaining them, within the furnace. Charcoal supplied with a gentle (!) air blast will certainly produce the required temperatures. One problem remains getting heat without excessive ash floating around (and sticking to the surface of the beads).
One very successful addition to the interior of the furnace is to place a triangular diverter on the wall directly opposite the tuyere entry. Combined with a slight down angle to the tuyere, the net effect is a spiral pattern to the air flow and thus heat generation pattern. In this furnace, this circular pattern was clear in the way the charcoal was consumed.


Our current furnaces provide two possible working methods.
One is inside the furnace, through a port cut into the two long axis ends. For this furnace, Neil and I made slightly different cut angles and locations. I had kept to a more rectangular shape, and also cut the angle of the upper edge so it sloped upwards into the furnace. Generally this proved more effective in reducing some of the volume of hot air blast escaping towards the operator.

The second working area is inside the exhaust stack on the top of the furnace. Although a fresh charge of charcoal certainly provides enough heat here to bring the glass to working temperatures, the effective duration remains short. I think some additional refinements in the shape of the upper structure may improve the function of the stack area.

I worked as much as possible with the two types of tesseri (broken tiles) that Neil had purchased. By this point I (more or less) have managed to figure out how to take an irregular rectangle and wind it up to a roughly ball shape on a mandrill.

One important addition to our working method was developed by Neil over this session.
I can more or less manage a bead shape, even a bead with some decoration. Where it comes apart for me (literally) is in getting the finished bead off the mandrill! Neil had looked closely at a video of traditional workers and seen that they were able to tap off a still hot bead with a metal tool. After a number of failures, he discovered the key is in tapping the mandrill first, which seems to break up and loosen the applied clay separator / resist.

Although not shot at Goderich, there is a video clip on YouTube which shows an earlier experiment in this series.


For more information on the ongoing research into Norse glass beads and making, see the area on the DARC web site.



* Evil Nefarious Plan:
Is to introduce an element of archaeology, specifically Experimental Archaeology, into the fabric of the Festival. Next year marks 20 years for the Earth, Air Celtic Festival. I have tentative approval to build and operate a Celtic Iron Age, slag pit styled, iron smelting furnace as the public demonstration. In conjunction, my intended Celtic College offering will be 'Ancient Celtic Ironwork'. Students will work with a ground pit charcoal forge, bellows air and small block anvils. The likely projects will be small knives and spear points. On the last College session, they will aid in constructing the smelting furnace.
The day long firing of the furnace will be a major demonstration at the Festival, allowing for direct participation of students and others.
It will certainly be the very first time this type of furnace has ever been publicly presented in Canada, perhaps the first time in all of North America.

Wednesday, August 3, 2011

Viking Age Bead Making - at Goderich Celtic







On Saturday August 4 and Sunday 5, Neil Peterson (of DARC) and myself will be demonstrating Norse glass bead making techniques. The presentation will run roughly 1 PM - 4 PM, as part of the activities inside the Earth, Air Celtic Festival in Goderich Ontario.


For information and directions to the Festival web site.

Neil and I will be actually continuing our experimental work with Viking Age charcoal fired glass furnaces, based on artifact evidence largely from Ribe, Denmark. This has been an ongoing research and practical skills development project largely under Neil's leadership.


This will be a departure from what you have seen me do at the Festival in the past. In previous years, I have been illustrating proven techniques, which often have a historic basis, but generally I have been using modern tools. The focus is often towards the production of a finished object.

Here the stress is on experimental archaeology. The methods, even the exact tools, used by ancient Norse bead makers are not well represented by artifacts. The furnaces are represented only by flat base plates, no intact upper portions have ever been found. There is a LOT of guess work and trial & error involved!

So come watch us work - its sure to be an adventure. New discoveries can be made at any time!

Tuesday, July 26, 2011

DARC at CanIRON 8 - Iron Smelting Demo

Join a team from DARC on Thursday July 28 for a public demonstration of bloomery furnace iron smelting!
This is a FREE attendance part of the larger CanIRON 8, the Canadian national blacksmith's conference.


The event takes place at the Wellington County Sportsplex, 550 Belsyde Ave, Fergus Ontario.
How to get there

Demonstration starts at roughly 9 AM, with the construction of an 'Econo Norse' style furnace. This furnace type is quick and easy to build out of commonly available materials.


Preheat is expected to start about 10 - 10:30, with full smelting sequence starting about 11 - 12 noon.
The smelt will proceed over the afternoon, with final extraction of the bloom planned for about 5 pm.

The DARC smelt team will consist of:
Neil Peterson - Smelt Master
Richard Schweitzer - Lead Hand
Dave Cox - Loader

Come Join Us!

Monday, June 20, 2011

DARC at CanIRON 8 - Preparation Smelt

- June 11 at Wareham
Smeltmaster - Neil Peterson
Lead Hand - Richard Schweitzer
Loader - Sam Falzone

Furnace - Econo Norse (standard set up)
Ore - untested rock ore from Bratton's Run, near Lexington Virginia
Amount - estimated at roughly 23 kg
Bloom - 2.65 nice soft iron


Slag tap 2/3 through sequence


Neil peeks while Richard loads

Compacted and sliced bloom

Full smelt report with images is now available on the main Wareham Forge Iron Smelting Documentation:
June 11 / 11 Report

Sunday, June 12, 2011

Rocks melt good!

Saturday was our last practice smelt before the CanIron presentation on July 28.

A nice simple smelt using the econo-norse-in-a-can design, that was extremely well behaved giving us no grief at all until the very end when we went to pull the bloom.

We need to finish up the notes and add this (and other) smelts to the website but around 26 Kg of Virginia rock ore were melted down into a bloom that consolidated down to around 5.5 lbs.

Hopefully we can get a photo or two posted onto the blog soon.

Neil

Wednesday, June 1, 2011

Demonstration IRON SMELT : June 11



- The Dark Ages Re-creation Company will be mounting a demonstration IRON SMELT at the upcoming CanIRON 8 (Fergus, Thursday July 28)

http://www.ontarioblacksmiths.ca/CANIRON8/demonstrator/darc.html

The preparation / test smelt for this will take place on our normal
spring smelt weekend :

Saturday June 11
Wareham Ontario
Demonstration start time: 9 AM
Expected extraction time : 5 PM


Neil Peterson will be smelt master, demonstration team is Dave Cox, Sam Falezone and Richard Schweitzer.

Those interested in attending the June session can undertake the role of the general
public. This may mean that there may also be roles available as part of a
'hands on' aspect to the demonstration.

The smelter to be constructed is the Econo Norse type (firebrick with
sand packing). This is a modern system using easily available parts in its construction.
http://www.warehamforge.ca/ironsmelting/EconoNorse/index.html


In addition there will be some general grunt work to be undertaken, required to prepare materials for the two smelts. Smashing charcoal being one task. Breaking rock ore would be very
helpful.

Following the CanIRON pattern, this June 11 demonstration intended to be a ONE DAY
sequence.

How to get to Wareham?
http://www.warehamforge.ca/directions

Thursday, April 28, 2011

Travel to Bristol RI

Hija!
Snorri here.

As many know, I am by far the most travelled member of DARC. My most recent adventure was accompanying Darrell (Ketill) to Bristol Rhode Island. The purpose was to run an iron smelting workshop with archaeology and material sciences students from Brown University. The activities took place at the Haffenreffer Museum of Anthropology, with DARC's good friend Kevin Smith.

The trip down was uneventful, despite rainy weather. Here I am at the Duty Free at Fort Erie, grabbing a last Tim Horton's coffee before negotiating US Customs :


Now the purpose of the entire trip was to guide the students through building and firing a typical Norse styled Short Shaft bloomery iron furnace. Here I am helping to start the pre-heat / drying fire at the end of build day. The students were off smashing ore at this point, leaving me to manage the fire :


The next day (Saturday) was the smelt itself. This turned out to be a saga of pushed in tuyeres and massive slag tapping - a tale better told by Darrell. It pissed down rain that whole day, and generally was pretty miserable. Not having a direct role in the smelt activities, I wisely 'kept out of the rain'...

Sunday started warm and sunny, at least while I supervised Darrell packing up. Of course we Norsemen completely disregarded the *day* which turned out to be some high holiday for the Christians! By the time we finished packing, it was the middle of the afternoon, and we found almost everything was closed up tight. I was dearly wanting to go look at the Newport Tower, but Darrell had yet to have more than coffee that day, and whined about the 45 minute drive over to Newport and back again. So we just set off to return to Wareham.

Well the further we travelled from Bristol, the worse the weather got. Fatigued from his week of teaching, Darrell was more than ready to stop by the time we made Springfield Mass.

You know how tight Ketill is with his silver, right?
Not to 'waste' money on a major motel (which might have had a relaxing hot pool or something), he picked a small, kind of run down, place, well off the main highway. Asking for a non-smoking room, he ended up with what you are going to see below :


And yes, that is a Mirror on the Ceiling.
And yes, that is a round bed on a raised platform.

And NO we did NOT sleep in the same bed.
I hid out in the bathroom - with the door locked. (no ERGAY!)

'The head rests best in its own hall.'

Sunday, April 17, 2011

Bead Weekend

May 7 and 8 we will be building new bead furnaces for the summer, and spending some torch time practicing bead making skills on modern torches.

Gathering is up at Darrell's place. Please email for details

Neil

Sunday, March 13, 2011

Calendar Updated for 2011

Off to a slow start this year but the first pass of the calendar is now up on the website and blog.

Tuesday, March 1, 2011

DARC does FITP

Once again, it's the spring and the thoughts and fancies of the Dark Ages Recreation Company turn towards teaching at the annual conference - Forward Into the Past.

Forward Into the Past, or FITP, is a yearly day conference held in Waterloo, Ontario. This year, it's on April 2cnd at Wilfrid Laurier University.

More information here: www.fitp.ca


DARC is currently teaching 17 classes - including an overview of our trip to L'Anse aux Meadows last summer. We have a lot to say!