Thursday, July 12, 2012

Return to Vinland

 the Viking Age comes to LIFE
July 19 - 25, L'Anse aux Meadows NHSC

Newfoundland



The Dark Ages Re-creation Company has been asked by Parks Canada to mount a major presentation at L'Anse aux Meadows NHSC again this year. The 10 days of living history is to help mark the 'Presenting Norway' special event this summer.

Major physical demonstrations in the Norse Encampment area will include:


Rig on Music - Thorgeir  on the Spring Pole Lathe

Ka∂lin (or more likely Gudrin) on the Warp Weighted Loom



Ragnarr attempting to make a deal..


Kettil attempting to appear wise
 Living History - What does it look like?

DARC focuses on daily life in the Viking Age. The presentation will centre on a 'camp', with costumed interpreters surrounded by a collection of replica objects consisting of domestic goods, tools, and storage. At the rehearsal, simple overhead covers and tents will mimic the buildings which we will use at L'Anse aux Meadows. Individuals will be outfitted with the tools of their various trades and arts, all representing our real interests and skills. (We really are weavers and cooks, blacksmiths and carvers.) All of the objects seen, from clothing to tents, are based on specific artifact prototypes.
To the public, the members of DARC present themselves as actual voices from the past, with shared experiences as a group and direct personal histories. Individual members of DARC have prepared detailed characterizations based on their personal research into the Viking Age, developing considerable expertise in specialized areas. These characters are the 'common man': artisans, merchants or farmers typical of the Norse of the North Atlantic circa 1000 AD. Any conversation is likely to begin at this 'role playing' level of historic interpretation. The interpretive level used is then shifted to suit the needs of individual visitors. Some people delight in talking to a character from 1000 years ago, others are more comfortable with more of a modern commentary. These experienced interpreters are able to handle a wide range of topics and level of detail.

An interpretive team with proven experience!

Members of DARC are drawn from throughout Central Ontario, and are serious amateur living history enthusiasts, most with decades of experience. DARC has provided skilled and well equipped interpreters for special programs for all of the major events and exhibitions that marked the 'Viking Millennium' in Canada. No other group of Canadian re-enactors has as much accumulated museum experience. As a group and as individuals, members have worked both throughout Canada and the USA. Personal research has taken members to museums and archaeological sites across Iceland, the United Kingdom and Scandinavia. This will be the third major group presentation mounted at 'Vinland'. Individual members have been cornerstone to the 'Norse Encampment at L'Anse aux Meadows NHSC since its first inception in 1996.

On the Web : www.darkcompany.ca

Images by Paul Halasz , used with permission

A note to my regular Readers: 
I am leaving Friday July 13 for this presentation. I'm only back three days and its off to Goderich for the Celtic College and Earth, Air Music Festival. Three days after I finish there, its off to Owen Sound for Summerfolk.  Entries may be a bit spotty for the next 6 weeks!

Tuesday, July 10, 2012

Michael McCarthy 'back on the web wagon'

 

Uncanny Gallery at Mohawk Valley Forge  

Regular readers here will recognize the name Mike McCarthy. Mike is basically single handedly responsible for the formal creation of Early Iron in North America. I mean, before he stuck his nose in, there were certainly a number of people seriously working on bloomery iron smelting. But he was bold (crazy?) enough to actually contact a wide group of those involved and interested gather them together for the first 'Pre-Industrial Iron Symposium' at the Farmers Museum, Cooperstown NY in 2004. He would organize the second Early Iron again in 2005.

Mike is one of the very most intelligent people I know. In the classic definition of 'ability to process information and adapt to situations'. He would have been roughly in his mid twenties when I first met him (2003) and I was in awe of his massive raw energy. Up at dawn organizing, smelting all day, round table discussions late at night - and then staying up for hours more reading. Like a sponge. And *remembering* all that stuff.

All things considered, I am truly flattered that he considers me a friend. (Aw, shucks Mike...)

Anyway, the point of all this gushing is to point my readers to Mike's re-emergence onto the web, via his blog. Its not light reading. But thought provoking and concept deep.

Highly recommended.

Monday, July 09, 2012

Alloys for casting?

 Expanded from a contribution to the Norsefolk discussion group from this morning:

On 09/07/12 4:46 AM, Norsefolk_2@yahoogroups.com wrote:
3a. Re: Pewter casting
     Posted by: "Sam F"
     Date: Sun Jul 8, 2012 4:19 am ((PDT))

I would say, always go with a modern lead-free pewter alloy.  I know we're all serious history buffs, but history is not worth risking your health or well-being over. Lead poisoning is nasty stuff.

I have to strengthen what [earlier poster] Charles has said about being careful with copper based alloys. With the huge increase in base copper costs over the last decade, more and more cheaper metals are being substituted by manufacturers. Here read both Zinc and Lead. I personally had the same low level toxic exposure that Charles warned of this winter. Very nasty. Good news was that I too 'recovered' from the worst of it after a couple of days. I suspect both of us will have built up damage to our tissues (especially potential liver concentrations.) Very, very, double plus un-good.

So - care when purchasing bronze (copper tin) alloys is called for. Always ask for the Materials Data Sheet. In North America, suppliers are required by law to supply this information on request. It may mean dealing in larger quantities and with more expensive industrial suppliers - but toxic heavy metals poisoning is for *life*.

Sam has warned of the same thing with 'pewter'. Modern lead free alloys are typically 92 tin, 6 copper, trace of antimony. The antimony is a problem, but usually is in the range of 1 - 1.5 %. I've said this before, but lead free plumbing solder from your hardware is a safe alloy to use.

One important note however.
Lead in these mixtures does two things. Both are important to our understanding of just how historic casting process will work:
1) Acts to effectively lower the melting point of the metal.
Working with small crucibles in a charcoal fire, you can see why that might influence your results.
2) Acts to reduce the viscosity - improving the flow of the liquid metal. Historically you see lead added to copper alloys for the same root cause as is happening with the degrading of alloys today - cost. Losses during the casting process, and declining access to the correct metals was both accommodated by adding the cheaper and easier to get lead in an effort to 'extend' the valuable copper and tin in the mixes.
There are some ways you can work to reduce the impact of a 'thicker' flow with the modern tin alloys.
1) increase the size of the entry cone 'button' to help force the metal down into the mould
2) pre head your moulds

I have seen modern workers drastically overhead their metal to increase its pouring ability. I most definately would *not* recommend this. All the toxic effects come from metal as vapour - most likely if the metal is overheated.  Better just to adjust your mould!

One of the interesting things is taking a look at the existing stone artifact moulds, for hints of what metals might have been used.

Stone mould for a disk broach

You do find a number of moulds obviously intended for top filling in the historical record. I certainly have never had much luck attempting to top fill any of my own soapstone moulds using modern high tin / lead free alloys.
The reason for this is that the 92 % tin alloy is not only more viscous, it also has a much higher surface tension (which might be related ?). The result is that with a top pour, the metal 'pillows up' , not filling to the edges of the mould. For that reason, all the moulds I have used are designed for edge pour. (This also allows the use of a single backing plate.)

Past work - Soapstone moulds and cast pieces.
 Another clue to historic moulds is looking at the size of the entry cone, the space where the molten metal is poured when filling. A viscous metal requires a larger diameter hole to effectively fill.
Viking Age slate mould for a small belt mount
 Now, I had made a replica of this same mould, and have always had trouble getting it to fill. Note that it is set up for a edge pour. Also the entry cone is quite small and narrow.
 This certainly suggests two things to me:
1) The smith was attempting to be quite careful about just how much metal was being contained in the 'button'.
2) The narrow diameter of the entry line is more suitable for a very 'thin' metal at molten temperatures.
Taken together this suggest a use of bronze or silver as the intended metal for this object.
The melting points of the alloys of these metals ranges about 1800 F, easily four times the temperature required for a lead based pewter. With the mould pre-heated, a successful casing in bronze or silver can be made in a stone mould. (I do wonder if the back side of the artifact mould shows any heating scars.) I have not personally used any slate moulds, but I do know from experience that soapstone suffers some loss of surface detail due to chipping when used with bronze or silver.

Those interested in trying out simple soapstone moulds for pewter casting can find a technique guide I prepared.


Saturday, July 07, 2012

Some Recent Work

Along with the organizational challenge (read insanity) of preparing for DARC to L'Anse aux Meadows NHSC (Friday morning), and Goderich Celtic (three days after LAM), I have been really, really attempting to get some new work finished.

The first here is actually from mid June, one of three replica pieces ordered on very short time frame for Red Bay NHSC. The major object was a whaling harpoon, but the order also included this oil lamp:

Original artifact, as found
 
My replica

You can see the original is broken off at the sides of the handle, so anything above that line is purely speculative. I was shown an image of a replica that had been made for the Rooms at St John's, which had an 'iron' handle (obviously wrong) and a long length of S loop chain. I chose to reduce the size and complexity of this chain. (Which of course is not supported by the artifact in any case.)

I really wanted at least *something* new for Goderich, and Summerfolk the weekend following (Only three clear days between them, and there is an offload and re-pack in there too.)

The ideal would be to have something as completed objects that represented the three months I spent on the Bloom To Bar project:

Starting billets - bloom iron with spring steel cores
Rough forged blade blanks
I had prepared two billets I intended to lead to a very specific bladesmithing design. The top one is iron from Slag Pit 2 ( # 49 , November 2011 ) an the bottom from Black Rock (# 14, February 2006 ) In both cases the iron was deliberately used before much welding and folding had been done, specifically to allow cracks and irregular edges. I actually had gone a bit *too* far on the Slag Pit 2 iron, ending up with most all the flaws removed. For the second attempt, I was able to restrain my natural desire to forge in all the imperfections.

In the lower image, the two blanks are at different stages in completion.
The top blade has had the blade profile roughed out, and the first pass on forging the edge completed. The hilt is only vaguely shaped at this point however.
The bottom blade is complete in its forging. I had ground the rough forging to the basic lines I wanted for the finished knife. I find it easier to check for warps and wobbles if I do this first. Then the blade was forged again, first to correct any irregularities, second to refine the edge. (Forge thin - grind thinner). It is now ready to be surface ground, then the finished surface to be created on the belt sanders. Then heat treated. Then finish polishing. (The actual forging out of the knife shape is by far the fastest part of the whole process!)

Stay tuned for images of the completed knives...

Monday, July 02, 2012

Viking Age Smithing Tools?

Repeated from something I added to the topic 'Early Medieval Forge Tools' currently threading on  Don Fogg's Bladesmith Forum
View PostJulia  on 19 June 2012 - 07:44 PM, said:
I found the Mastermyr find too, but I seem to have entirely failed to spot the 3 Sledge Hammers. Returning to it I find 3 lovely large hammers of (69) 3.3kg, (70) 1.8kg, and (71) 1.5kg in size, these seem perfect for what I was thinking in my mind.


If you are serious about this project, I really do recommend that you invest in a copy of the primary report on the Mastermyr find:
The Mastermyr Find
Arwidsson and Berg
91-7402-129

Like a lot of reports of this type, it had originally been published in extremely small number, and was a massive pain to find a copy of. There was enough demand that Norm Larson Books out of California approached and got permission from the authors to get a re-issue. Now the volume is easily available, typically for about $25 - $30.
The book has all the objects described in detail, plus both scaled three view drawings and photographs. You just could not ask for a better reference!

As you mention above, the range of the hammer heads includes some that I would say were fitted with longer handles to use a sledges. One of the problems is that of course none of the actually handles survived. (Those teams working on the total replica series of all the tools have said that with correct handles attached, you can not actually fit all the tools and pieces into the box. There are some questions about just what pieces where found just where in the original discovery. A bit of a mystery!)

Personally, I rarely use a hand hammer over 1 kg, my primary is 800 gm (echoes the 724 gm one in Mastermyr). For me its about control, not power. Remember as well that the primary aim of the VA bloomery process was to produce a very low carbon metal, desired for its relative ease of forging. The modern obsession with high carbon tool steels is just that - a modern concept.

On punching, I have long thought the object described as a 'Nail Making Iron' (# 86) might be more accurately described as a hot punching block. My logic here is that the holes are only very slightly tapered - and the shape might just as easily be an effect of the hot punching method used to make the holes in the first place. Hand forged nails are typically taped *square* cross section - not cylindrical.
There are also two objects in the box described as 'Underlays' (# 77 & 78). These are simple ring shapes of thick rectangular stock. Again these would function well to provide the dead air space required for completing the hot punch process.

I have used the method suggested of completing a hot punch by laying the working bar on top of a wood block. Huge amount of smoke (!) but it certainly works well.

There is actually one surviving anvil from the VA that does have a hole in it for hot punching. (I had this pointed out to me by Mark Pilgrim at L'Anse aux Meadows NHSC.) This artifact was included in the exhibit 'Full Circle, First Contact' which travelled Canada and the USA after 2000. The object is illustrated in that catalogue (page 21) with the caption : "Iron Anvil, Norway, c.1000 AD. Courtesy of Bergen Museum, University of Bergen, Norway."  (you do have to look closely on the image below. The bottom edge of the hole can be seen just at the base of the horn.) I should warn you that there are not very many surviving artifacts from the Viking Age, and this is the only anvil with any kind of a hole in it I have ever noticed (and one of the few with a horn for that matter)
    Attached Image
    Display case from 'Full Circle- First Contact'

Sunday, July 01, 2012

Escential Smelting Tools

Question : What tools are absolutely required for an iron smelt?

I think these are the absolute minimum

L-R : Radner / Bloom Hook / Bloom Tongs
A length of roughly 1/2 diameter round mild steel rod, about 3 feet long plus.
One end cut flat and square, the other end forged to a blunt chisel tip.

This needs to be small enough diameter to easily fit down the inside of your tuyere. The square cut end can be used to clear slag blockages ('uvuloids' *) that form on the interior end.
The tool reversed to the chisel end can be used to poke holes into the lower slag bowl for slag tapping.

For a historic presentation,  I would suggest taking a piece of 1/2 square and forging it down to an octagon shape. This will produce both the desired profile, but also remove the modern machine made edges and look.

2) Bloom Hook

The working end forged from something like 5/8 square or 3/4 x 1/2 flat. It should have a right angled bend ending in a steep point, about 2 inches along the bend.
Mike McCarthy showed me the mounting system seen in the image. This allows for the attachment of the shorter working end on to a (replaceable) wooden handle. The metal has the upper end forged to a short right angle bend (same side as the lower hook). A forged metal ring (in this case made from a short section of steel pipe to save the time welding a ring) holds the working tip to the handle. You can see the wood is prepared by cutting a hole and a slot near the end. When the ring is driven on, it locks the working tip on to the handle.

Mike's handle attachment system

This is a pretty versitile tool. As a hook it can be used to pull loose a bloom for top extraction. It also can serve as a rake to pull free hot slag during tapping.

3) Bloom Tongs

On either top or bottom extraction, you are going to need a pair of oversized tongs to grab the bloom with. The style shown here is pretty much as simple as these can get. Made of roughly 3/8 x 3/4 flat stock. The full width is maintained at the pivot point (hot punch for a 1/2 diameter rivet). The metal is then collapsed down from rectangular to flatten at 90 degrees to the original orientation for the jaws.
On mine I cheated and welded on two sockets forged down from pipe. This allows replaceable wooden handles. Remember that you need enough length to allow you to reach down inside the furnace if you intend top extraction - that is at least 32 - 36 inches total. An alternative would be to make them up to use the ring and slot system described above. (Or just go for a full metal rein?)
 I have adjusted my bloom tongs so fully closed there is about a 1 inch gap between the jaws. More importantly, they are set so that with the jaws open to roughly 6 inches, the distance on the handles at the mid point is only about 10 inches. (This so you can get the jaws around a larger bloom, but still fit inside a standard furnace diameter.)


Things you need - but likely have around already:

4) Knife

You are going to need to cut into the clay walls to set the tuyere and make your tap arch. Obviously you can just use your belt knife for this. Personally, I don't like to use my working knife for this (wrecks the edge) and so keep a 'garbage' knife in the smelting tool box just for furnace construction.
Outside a historic situation, a small dry wall saw works wonders - especially if you are using straw cobb construction.

5) Medium / Large tongs

These would be the same sized tongs you would use for working larger diameter stocks (adjust for roughly 2 - 3/4 thick materials). The same size you would keep for working axes and the like. These for handling the bloom as it is cut into pieces and compressed.

6) Sledges

Again the same tools you would use for working heavy stock sizes. I normally work with two strikers, and keep two hammers in the 5 - 8 lb range on hand. Since I normally am not working with skilled *blacksmiths* during iron smelts, I find the lighter sizes allow for the required control.

7) Axe

For cutting the hot bloom. You *could* use one of your splitting axes for this. I personally keep a dedicated (cheap and pretty rough) axe just for bloom splitting. The combination of extreme heat and pounding will pretty much destroy any axe as a functional woodworking tool afterwards. I have wrapped about six inches of the handle below the head with leather to protect the wood.


Things you can get by without - but are nice to have:

8) Rake / Hoe

Mike also showed me a simple flat plate on a handle style, all made of wood. Kept soaked, it deals with raking away ash, burning charcoal and hot slag pretty well. Fast to make and considered a disposable.
Of course a small garden hoe works very well here.

9) Shovel

I personally like to keep all that hot stuff picked up and kept well away from the work area. In the frenzy of a major slag tap, or during extraction, the last thing you want to have happen is kneel on a hot bit of something! Again, in a historic situation, a simple wooden shovel kept soaked down works fine.

10) Ore Scoop

With gloves, its certainly possible to just pour your charcoal straight from a bucket into the top of the furnace. For ore additions, I personally like the control of a small scoop with a handle on it for adding ore. This also allows you to use a 'standard measure' for your ore additions. Can easily be made of wood as much as metal.


For top extractions

Thumper

Mark Pilgrim, using the Thumper for Vinland 5

This is a roughly 4 inch diameter log section, with handles on the other end. I use a piece about 30 - 36 inches long, plus the handles (enough to reach the bottom of the furnace). This is used for compressing / loosening the hot bloom in place down the inside of the furnace. Not everyone uses this particular step, but we have found it effective.

Scoop

This is a shallow bowl, about 4 inches in diameter made of heavy steel plate, set at right angles to a long handle. Again the ring and slot system can be used to secure a longer wooden handle to the working end.
This is needed to clear the last remaining burning charcoal from the furnace to expose the top of the bloom.


For bottom extractions

Pry Bar

Lee uses a length of roughly 3/4 diameter bar about 4 feet long to shove the bloom *up* to loosen it when doing his standard bottom extraction. The bar has a short 'sheppard's crook' end to it to increase the leverage and reach up inside.


There is also a section on smelting tools as part of a consideration of the Vinland / Norse iron smelt in my paper 'Iron Smelting In Vinland' - (as a pdf)



* Correction added by Vandy:

Do you mean 'uvuloids' as in "uvula" the bit at the back of the throat, and Dairy Queen commericals?


Yup - that is exactly where the term originated. Blame Mike McCarthy!
 

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

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