Wednesday, May 31, 2006

New Smelting Area!

Over the last weekend, a crew of people from DARC came up to the shop at Wareham and worked creating a special purpose area for our iron smelting.
The work crew consisted of Neil, Dave, Kevin, Ken, Selena, Karen and Vandy.

A few images of the results are posted up :
http://www.warehamforge.ca/temp/smeltarea

The new smelter area is wonderful. Rail ties were installed at the natural edge of the high water line on the pond. The small slope that defines the pond area was cut back and revetted. The area between these two lines was leveled. An overhead cover of sheet steel supported by four posts was constructed. Some finishing work like installing steps to the work area was completed. The flattened area under the roof is roughly 10 x 10 feet. You can see our next smelter inside the metal forms, which will give an idea of scale.
The intent is to build a pit style forge in the centre at upper ground level for re-heating blooms for consolidation and cutting to hand forgeable pieces. The use of the loose concrete blocks will allow us to install a second smelter on the left hand as desired latter on.
I set the distance on the side poles at 8 feet. This will allow me to block in the sides come winter with a couple of pieces of wafer board. With addition of a tarp on the pond side in theory this should break the wind and hold enough heat from the smelter to allow us to work later into the winter if we are inspired to.

Kevin led the group in constructing the shell for the smelter. This is set into the earth bank. Once the clay has firmed up and the forms removed, the gap between the cob cylinder was be packed with the usual mix of ash and sand. Other than that, only setting the tuyere and cutting the tap arch remains to be done. This is intended to be a re-usable smelter, something we tested last year. This smelter is a bit taller than last years series, combining what was learned from Jormungund at Smeltfest 06 earlier in the year.
http://www.warehamforge.ca/temp/smeltarea/smelter03.jpg
- shows the construction. The paper clinging to the surface serves as a release from the sheet metal form used.

Our next smelt is planned for June 10. Kevin and Dave are the smelt masters. I will trouble shoot as needed, but mainly want to shoot some video and better still photos of the process.

Friday, May 26, 2006

COURSES - update

Just a fast note to those interested in the upcoming courses at the Wareham Forge:

June 3 / 4 - Iron Smelting - CANCELED

As of todays date I have had no requests about this program. As the raw materials for the smelt cost $300, I require at the full four students to go ahead with this course. Unless something radically changes over the next couple of days - this course is CANCELED

June 16 / 17 / 18 - Introduction - ONE remaining

As of todays date, I have a total of THREE paid deposits for this program. This leaves only ONE place remaining. If you are interested, you should e-mail or phone me right away to arrange for a deposit ($100) by either paypal or your credit card.

July 8 / 9 - BLADESMITHING - spaces OPEN

As in past years, I let the exact content of this course date be determined by student interest (as expressed by deposits!). I have had ONE paid deposit / request for the 'BASIC BLADESMITHING' program. As of todays date, this leaves THREE spaces open. Register with your deposit today.

For more information on the courses offered:

www.warehamforge.ca/train.html

Darrell

Coins and Coin Dies

I recently had a inquiry about creating a set of replica Viking Age coin dies. The questioner was wanting to use the dies as part of a living history presentation, and wanted to be able to hand out the coins produced free. This is a general interest version of my reply...

There are two elements to this project - the dies and the disk blanks

On the dies:

I should warn you right up front that I have been ACID ETCHING the patterns in - rather than engraving them. I've tried engraving a couple of times (and did make one set of simple dies that way) - but truthfully have NOT had a lot of luck with the technique. Engraving is its own specialized skill, and requires special tools to undertake correctly.

On my own dies (for the coins seen on the web site) I quite purposely reversed the impressions. I have raised letters and lines - which cut into the disk surface. This was done to create an obvious point of difference between the replicas and the artifacts. (concern over counterfeit) Note that with the acid etch method, it is easily possible to create the more correct incised lines. The etched dies do have a physical action a bit different than engraved ones. Engraved lines are triangular in cross section, so the metal is forced into a sharp peak. Etched lines are somewhat circular in cross section, so do not produce quite the crisp lines as would have been on artifact coins when new.
I have also mirror imaged the patterns for the same reason (thus two points of difference).

Second part of the dies is the physical shape of the metal itself. I have two sets of dies I use for the two different coins seen on the web site. The first (for the York coins) was made as a 'production' die. It is constructed from a blank of 1045 tool steel. This means the dies are quite durable, my own set has made several thousand impressions in the 12 plus years since I created them. But these are straight polished cylinders of clean steel.
My second set of dies are replicas of the actual dies found at Coppergate. (Mind you - they do have a different pattern on them). These are forged from mild steel. The artifact dies have been upset to one end then forged down to a square tapered peg. Before the etching, I water hardened the mild steel - with sequential hardness towards the base / striking end. So these copy the FORM of the period dies.

I will (and have) created dies both as production and reproduction level of detail, for individuals and museum programs. If anyone out there is seriously interested, please contact me directly. Price is in the hundreds - not thousands (!). I would prefer NOT to duplicate the patterns that I have selected for my own replica silver coins. Note that my customers for the replicas are mainly museum gift shops, as wholesale. I figure my past work in this field and a certain reputation gives me a leg up on any potential competition in that market.


Your second problem is the cost of the disk blanks

When I initially got involved in the coin project, it was primarily to provide a good physical demo at a community medieval festival (back in 92). I knew from my own work with living history, that coins were an ideal teaching tool. Once you have dies - the actual process is quick, and the other tools required are minimal. A wood block, a heavy hammer. Round out the presentation with a pan balance with weights (also available from the Wareham Forge) and a set of cutters. Lots of pop culture references here! A very solid 5 minute public presentation.

My problem, like yours, was were to get the metal disks. I did consider cutting all my own, and made up a couple of test stamps to cut 3/4 inch circles. I found that in copper the cut disks still had ragged edges, so had to be laboriously filed smooth. With a machine press, this step could be avoided - but this is an expensive tool I don't have. I also tried aluminum and sheet pewter (the tin alloy). Lead sheet worked extremely well - but although I did have a quantity of this as scrap - I certainly did NOT want to be handing out toxic materials to children!
I contacted a couple of small machine shops, and the cost per unit for disks in copper ran in the $1 each range - on a 500 to 1000 minimum order. You might see if there is a Tandys that still sells copper enamel supplies. Pre-made copper disks used to be widely available for this reason, I remember paying about .25 each for this size way back when. You might be able to hand cut 22 or 20 ga copper, but its a small circle and this would be slow (maybe ok as a demo however).

I figured at that price I'd look at real silver. I was looking for 3/4 inch size, and 22 gage thickness. This is almost exactly the size and weight of the original coins. The range of cost on this was amazing. The cheapest I could get silver disks made from a Canadian manufacturer was $2.25 each. This on an order of 50 ounces of silver (about 1500 disks)! Curiously, I did some web searching, and found an American supplier with a wholesale price considerably less. The last order I placed (about two years ago) for 10 ounces (there's a price break there) still had the disks at a price that allows me to keep my 'finished coin' price at $5 CDN loose / $7.50 CDN packaged.

www.warehamforge.ca/npenny.html

As a trade token, I only get at best one out of every 100 coins returned. Most everyone wants to keep the coins as a cool thing on its own. It only happens at the rare SCA event, and even then only the same few people. I tried to introduce the coins as trade tokens 10 years back. I offered to bankroll any area merchant who would accept the coins in trade. Although a couple agreed - none of the SCA community itself bothered with it.

And truth be told, I attend few SCA events these days, and those mainly teaching events. I rarely bother with attempting to sell anything there any more. That community does not support historically accurate replicas in the only way that counts to a skilled artisan - with purchases. You get what you pay for...


Darrell

Thursday, May 18, 2006

Forges - What is is worth?

> I am trying to find out how much a forge runs. My father in North Dakota
> has a small round working forge I believe, that is about the diameter of
> a metal trash can lid. It has sat out under the eaves in front of his
> garage in Fargo for a couple of decades and recently a fellow has come by
> several times offering to buy it from him. He is so persistent that I was
> wondering what the thing is worth.

The current prices for NEW smithing equipment is best researched at the Centaur Forge web site. www.anvilfire.com/centaur

What you have is a 'farmers forge' from around the turn of the last century. These were relatively common on larger and more developed farms for fast repairs. (Like modern torches or an arc welder would be). They were sold as kits via the major catalogues - Sears Robuck in the USA, in Canada via Mr Eaton. For about $25 you got a small forge like you describe, a roughly 100 lb anvil and various hand tools. (Note that is is the source for all those smaller hobbist sized anvils now kicking around.)

The current fair price for one will depend on:
exact design
condition
relative rarity in your area
demand.

These forges come in roughly two types - an older style with a leaver and ratchet assembly that drives a leather belt to a small blower - and a newer style with a smaller blower with a hand crank. Size of the blower will effect price as well on the second type. There is also a chance that the forge was originally intended for a separate blower .

Loosely, there are two weights of bowls - ones with a heavy cast iron - and those with a thinner stamped sheet bowl. The early leaver forges will always have a heavy cast bowl. Crank blowers may come with either.

The overall condition of any attached blower or mechanical is a big factor in setting price.

In Ontario right now, a separate stamped dish forge in good condition should expect roughly $50. The light dish with small working blower runs roughly $75. Heavy dish may go in the range of $100 - $125, depending on blower and overall size.

Note that the rectangular profile forges with a full cast iron fire box set into them are considerably more.

Rarity in your area will be a big factor as to what is considered 'fair market value'.

I'd also check and see if there is a local chapter of the Artisan Blacksmith Association of North America, ABANA, in your state. They will be able to assist in finding a buyer for you as well as advising on fair pricing. Note that Blacksmiths are notoriously tight with money!

Tuesday, May 16, 2006

Tripods in the Viking Age

I have had a couple of conversations recently rolling around round rods - and tripods and camp ironwork in general. For those concerned with the overall look and accuracy of a camp - consider this taken from ARCHMETALS:

Date: Wed, 10 May 2006 17:21:27 +0100
Subject: Re: Rolled Iron Round stock

"A metallurgist friend is giving a talk at a historical site and needs to
know when rolled round rod was generally available for sale.

Anyone have a good off the cuff idea? "

Thanks

Thomas Powers

------------------------------

"The mills around London that produced barrel hoops were operating under =
a patent of c.1680 that also dealt with round and half round iron. =
However I suspect that it was not often made. First the bar was slit in =
a slitting mill and then passed through the rolls again to give it the =
desired section. I have seen a patent of c.1780 for the classic 19th =
century rolling mill, though the mill was in fact intended for rolling =
copper. Henry Cort applied this or something like it to iron in his =
1784 patent (for puddling). However his process seems to have had a =
slow take up, perhaps because ironmasters did not wish to risk being =
asked to pay a royalty for the use of his process (though no one did pay =
one after 1790). The answer to your question is thus probably 'about =
1800'. Nevertheless, (as indicated) there are complications. "

Peter King


**********

So - what this should tell you is - basically NO USE of round profile rod for the Middle Ages - Much less Viking Age. Round profile can be created by taking square rod, hammering to octagon, then hammering the facets off to more or less round. The object that comes to mind here is the cauldron hanger from Sutton Hoo (circa 600) - which is interpreted to have a number of individual chain elements (not all!) first profiled this way. Mainly however, anything for the Viking Age should be created from square at best, and better still rectangular, profiled stock.

Long shafts of iron for tripods are basically not correct either. Yes - there is the **single** sample from Oseberg. But I suggest that is is a specifically created grave offering, and was never intended as a working cooking tool in the first place. (I could drone go on about that - but check the piece on my web site 'Aunt Martha's and Damnthings'.) Remember that in the VA, raw iron for the smith was purchased primarily as short 'currency bars'. If nothing else, making each limb of a useful iron tripod will require welding at least two of these together and then laboriously (in a small charcoal fire and on tiny anvil) hammering out the bars required. What a waste of valuable metal!

As far as I ahve been able to tell, the 'standard' modern re-encators tripod of three four foot straight steel rods with end crooks or loops is American CIVIL WAR at best. I have seen photos from that conflict that show them.

Fortunately, the most historically accurate Viking Age camp tripod is also by FAR the easiest to make (and the cheapest too!). A simple tripod made from three long poles / saplings. Lashed together at the top, with the free end of rope hanging down to end in a foot or two of rough chain with a simple hook. What could be easier? Has added value in that it helps define a box around your fire pit to add safety.

Friday, May 12, 2006

What things Cost...

This rant was originally written for NORSEFOLK - a discussion group for people interested (primarily) in re-creating the Viking Age. I've edited it into a stand alone article here:


"...I'm thinking of starting to quote people in terms of their own
incomes. "That will cost one week's pay" sort of thing...."

In my OWN dealings with the general public I have to admit that I have been following that same method of 'relative value' for some long time now. As you might guess (those who have checked the web site) I have a number of 'oars in the water' that I use to support myself. I have been a self employed artisan since 1992. To call this state 'making a living' might be over stressing what I consider a 'living' - at least compared to what the defined National Poverty Income Threshold is pegged at! (but I digress - again...)

So to re-enforce what Meghan has said in the quote - how about object price / value as a reflection of :
cost of raw materials
time of production
skills required
specialized equipment

I've added that last on there. The conversation was drifting towards textiles, but still consider the 'cost' (under the same framework) invested in the loom required for weaving the cloth. Remember to consider maintaining the work space in there too.

And as suggested - linking the relative value of an object back to modern day wages is a very good idea. What does even a factory worker make in a day? Much less someone of comparable training and acquired skills? One good measure (at least for Canada) is the pay levels of historic interpreters at major (Federal / Parks Canada) living history museums. Last I checked (10 years ago), trained historic interpreters make something in the range of $15 - $17 per hour (with benefits). Those considered 'artisans' with technical training or skills were in the range of $23 - $25. (When I stopped working at Black Creek in 1992, I was earning $24 K per year on a 9 month season.)

That should suggest a 'pay rate' of something like $500 plus a week - or at least $100 a day. Personally, with over 25 years in my own field, with my education and skills, I figure I should be considered to be roughly the equivalent of a mid level high school shop teacher - at least some place about $50 K - or $1000 per week.

Please don't fall into the trap of looking at flat hours at a work bench as the final cost of an object. As was correctly described by someone - bear in mind things like research time. In fact, my own experience is that actual PRODUCTION is at best something closer to only 30 - 25% of the total time expended 'at work'. Several people talked about various alternate sources of raw (fabric) materials. What about the time required to find those sources - and travel to them for purchasing? What about the time required (again mentioned) in discussing the project itself with the potential customer? Specialized set up for a specific project? Filling out government business paperwork? Promotion (like the time this message has taken!)?

In a 'normal' week I an involved in 'business activities' roughly 50 - 60 hours. I typically spend from 7:30 through at least 10:30 on communications, promotion related, required business paperwork. On any given day if I actually am inside the workshop for 3 hours I consider that a productive day. I normally 'work' 13 1/2 days out of 14. Every weekend from roughly early April to mid November is tied up with teaching, shows or demonstrations. 'Holidays' are traveling - and then working.

Another factor to consider is that experience and skill (not necessarily the same thing) and investment in specialized tools all can decrease the relative time it takes for physical production. I can do things now in much less time it took me to do the same operation - 20 years ago. Should an object cost less because that acquired skill has reduced the time expended? I personally invested in a quite expensive air hammer for the shop, plus the air compressor to run it - then spent about a week installing it. This greatly speeds the time required for some work, plus certainly reduces the physical effort expended. Should I charge less now for an object using that tool because of all that investment?


So my end conclusion here is - you get what you pay for. Skill has value. Knowledge has value. Good quality work is worth what the artist requests. Sure - we all like to haggle, and maybe there is some wiggle room. Appreciate the value of craftsmanship, and never forget the highly specialized requirements of the objects that duplicate lost historic artifacts or utilize hard learned traditional skills.

Darrell

Monday, May 08, 2006

On Safety Eyewear...

Rose Didymium Safety Glass

TECHNICAL DATA

" Rose didymium is a high luminous transmittance filter specifically designed to absorb bright yellow sodium flare (589 nm) which occurs when heating glass. Didymium lenses protect the eyes from certain visible and UV light produced in the glassblowing process. They enable the glassblower to see the glass while it is being worked in the flame.

This is the classic filter that has been used for many years in all types of hot glass applications, as well as kiln working. The lens is dichromic (exhibits different colors under various light sources). Under incandescent light, the lens is a pronounced rose color, but changes to greenish blue under fluorescent light.

The spectral analysis of this glass at 3.2 mm thick indicates that it has good protection against ultraviolet radiation up to 360 nm, has excellent filtration at the sodium line, and excellent overall visible transmission from 400 nm to 725 nm. The glass does not offer much protection in the near or mid infrared ranges.

In general, this lens is adequate for many glass-working applications where the amount of radiation generated is low.

Suggested uses:
Beginning lamp-work using hot head torches and MAPP gas, or propane torches with soft glass. Periodically viewing small kilns, acetylene torch work on solver and gold jewelry, enameling of jewelry, and operation requiring occasional viewing of heat sources in excess of 1000 degrees, but not for use with high pressure torches on hard materials where very high temperatures are generated. "

from the East Carolina University Glassblowing Services technical web site, information listed as ' Information provided courtesy of: Phillips Safety Products '

I have been using these to protect my eyes in the forge for years (almost 20 at this point). I highly recommend them for anyone considering a long working life in the forge. My standard is - If you look at something and its bright enough to make you see spots when you look away GET A PROTECTIVE LENS. Those I have seen (too often!) who do things like use oxy torches or forge weld without protective lenses are just plain foolish. A blind man cannot be a blacksmith.

Centaur Forge lists them - but seems to be always out of stock. Also the most expensive.

I checked with a number of glass blowing suppliers

http://www.jodelglass.com/shopsite_sc/store/html/page26.html

has the best selection of types. Ships orders to Canada, uses Paypal

http://www.glassmart.com/didymium.asp

is the best price. Ships to Canada - but only via credit card. I ordered from them myself about a month ago. Their sales guys have been extremely fast on any questions. The package arrived quickly and in good order.

Monday, May 01, 2006

Charcoal in smelting - 'Size does too count'

This is modified from a post made this morning to EARLY IRON - related to charcoal in iron smelting:


Its my contribution to take the complex, miss some of the details, then attempt to over simplify it to allow the more knowledgeable something to discuss at length. Bear that in mind:

Daniel wrote:

1. Preferred wood (hardwood, softwood, mesquite, etc) and why

My understanding is that the species of charcoal does not really effect the total energy produced all that much. However the rate of energy delivery and most importantly the amount of waste ash produced will vary by type. Balance this against the fact that from the archaeology of Scandinavia at least (the only set I know about) there is no indication that specific wood types were selected for smelting. The range of types and mixture from the charcoal fragments pretty much matches the range and mix found from pollen remains at the same excavation. They seemed to have used whatever trees were handy when making the charcoal. (In fact its ORE that determines the location of an Early Medieval / Dark Ages smelting operation.)

Most of us look like we are using modern commercial charcoals, which tend to be primarily oak with some hickory. Maybe the odd assortment of other types. My group has been using Royal Oak for the last several years, which we have high praise for. It appears to be scrap from making decorative moldings - and is almost all oak.
Lee and Skip are making their own charcoal in a metal retort. Again they are starting with scrap from a molding plant - and it looks like this is mainly oak as well. (They should really comment on this!)
Mike has made charcoal using both the pit and low stack traditional methods. I believe he was working with dead fall branches from a wood lot. You should nudge him to tell you more.
At Early Iron 2 - commercial charcoal was purchased. This material was mainly oak, and had every indication that it had been made from old rail way ties. We found a LOT of debre and foreign materials - rocks, fused clay - pieces of metal - mixed in.

In any case, all of these charcoals provided good fuels in the end.

2. Has anyone tried using the pressed briquets (Kingsford, etc.)? I don't trust them myself because of the other stuff that's been added to bond them into briquets, but anyone with experience please weigh in.

Because of the way they manufacture briquettes - I can't imagine they would be useful. Briquettes are made of a mixture of clay dust, charcoal dust - and used motor oil. Nasty! The high volume of garbage (the ash and clay) is certain to mess up the interior of your smelter.

3. lump size -- do you break up the charcoal and sieve it for specific sizes?

Ok - now we get to the 'complex made too simple' part:

There is a relationship between the ore type and purity, and the reaction time required for all the various chemical changes to take place inside the smelter.
The reaction time is roughly controlled by first setting the stack height of the smelter. The next variable is the size of the ore particles related to the size of the charcoal particles. As you might guess - these three things work in combination to determine how fast an individual ore particle will heat to the reaction temperature - plus how long it remains in the reactive zone of the smelter.

Air volume works in here too - but I'm leaving that part out for now. (ok?)

Looking at archaeological materials, then MUCH trial and error (on mainly Lee and Skips part) has resulted in the rough dynamics that many of us are working with;

smelter size of roughly 10 - 14 inches (20 - 35 cm)
smelter height above tuyere of at least 16 inches (40 cm) - but ideally closer to 20 inches (50 cm)

and

roasted ore particle size roughly pea to rice, with the dust included
(although this varies with type of ore)
charcoal particle size of roughly 1 inch (2.5 cm) with the dust screened out.



I have been using mesquite and found it requires *A LOT* of air in order to work well. ...
.. comment on ahistorical blower/bellows that they are using or what they look for in a blower/bellows?

Air is a hot topic!

More exactly, the Sauder and Williams basic process has been proved to work consistently and predictably. High volumes of air (500 - 1000 liters per minute) are required.

One of the basic questions for those of us attempting to work backwards towards Early Medieval methods is how to either :
design and document a large volume air delivery system
or
modify the basic sequence to allow known lower air volume equipment to actually correctly produce workable iron.

In short - almost everyone who attempts to use low volume air ends up with much slag and little iron. As soon as you bump the air up an order of magnitude - you start getting large masses of workable iron.

Darrell

 

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

COPYRIGHT NOTICE - All posted text and images @ Darrell Markewitz.
No duplication, in whole or in part, is permitted without the author's expressed written permission.
For a detailed copyright statement : go HERE