Date: Fri, 9 Jan 2004 16:19:29 -0500
Subject: [SCA-AS] Links: Medieval Metal Casting (Silver, Pewter, Bronze, Gold,
Iron, Steel) and Smelting
Greetings. This week's Links List comes to you via a request from Phlip for
metal casting information. Since we haven't covered that subject before, Here
You Go! You'll find info. on Silver, Pewter, Iron, Bronze, Gold and Steel.
many sites cover several metals. This is not a smithing Links List (we've
covered that subject in the past), but is all about smelting and casting.
As always, please share this list with those who will welcome the information.
Cheers
Aoife
Dame Aoife Finn of Ynos Mon, OL
Riverouge
Aethelmearc
Medieval Sourcebook:
Accounts of Tin Mining in Cornwall,
Stanner Charters of 1198 & 1201
http://www.fordham.edu/halsall/source/1201Tinmines.html
(Site Excerpt) All miners and buyers of black tin, and first smelters of tin
and merchants of tin of the first smelting have just and ancient customs and
liberties established in Devon and Cornwall. Likewise just and ancient weights
of the first and second smelting of tin, determined by the oath of the above-mentioned
jurors, and marked with the stamp of the Lord King, shall be kept....Also
all men have the common right of buying tin by just, ancient, and free customs,
as they are accustomed to have and ought to have, by the mark from any thousand
weight of the second smelting.
Regia Anglorum: Charcoal Burning
http://www.regia.org/charcoal.htm
(Site Excerpt) Firstly, why make charcoal? The simple answer is that no other
combustible substance generates the heat necessary for the forging of metals
(by the definition above, 20th century coke is "coal charcoal"). The process
basically consists of Burning - or literally charring - wood at a very slow,
controlled rate so that the combustion is never allowed to complete and thus
turn the raw materials to ash. This is achieved by controlling the amount
of air involved in the reaction - basically, covering the whole caboose in
earth. The process takes about 24 - 30 hours for 3 - 4 tons of wood (the amount
we had available in the lakes) and produces, in ideal conditions, about a
ton of charcoal. See Also: Iron Working http://www.regia.org/ironwork.htm
A Home-Built Charcoal Fired Foundry
by Gene Elliott (c) 2000 (edited by Steve Kaehler)
http://www.seattlerobotics.org/encoder/200008/GEAR_article.html
(Site Excerpt) Since I've always wanted a small, portable foundry set-up that
I could take along for field demos and other special projects, building this
furnace gave me the perfect excuse to provide my very own portable small parts
casting foundry. The picture shows the main apparatus involved.From left to
right, the molding flasks, foundry, the blower hose....
Iron Production-Techiniques and History by Bo Justusson
http://www.algonet.se/~justus/railways/rw71iron.htm
(Site Excerpt) Old times. There have been hundreds of iron mines and blast-furnaces,
and around thousand iron mills. Most of them in Bergslagen (far north-west
of Stockholm, see map on Early Railways-page). This reduction has of course
meant enormous changes for the people working in the Bergslag region.
TIN SMELTING AT THE ORIENTAL INSTITUTE
http://www-oi.uchicago.edu/OI/PROJ/GOL/NN_Sum95/NN_Sum95.html
(Site Excerpt) The archaeological excavations at Kestel and Göltepe in the
Taurus Mountains of Turkey, led by Professor Aslihan Yener of the Oriental
Institute, have disclosed an early Bronze Age tin mining and processing operation.
There is at least one ancient mine in the area of the excavations, now named
Kestel Mine, but there are undoubtedly more yet to be found. The experiments
aimed at establishing production techniques and were designed to determine
the magnitude of tin production at the site of Göltepe.
Early Smelting and Metallurgy
http://www.unr.edu/sb204/geology/smelt.html
(Site Excerpt---and page down for a period illustrationof a smelting furnace)
Smelting was accomplished initially in an open fire. A hole one to two feet
in diameter was dug in the ground. The hole was lined with fire-resistant
clay or stone. Charcoal was placed in a layer on top of the clay, then was
covered by copper ore. Charcoal burns particularly hot, raising temperatures
enough to melt the copper. The charcoal also releases gases that react with
the copper minerals to reduce them to copper metal. A molten mass of the dense
copper formed, topped by lighter waste products, or slag. When the mass was
cool, the brittle, glassy slag could be broken off, leaving a cake of refined
copper behind. The furnace in this method is called an open hearth. Remnants
of open hearths have been found in Sumerian ruins.
Smelting, Casting, Smithing
http://www.rmsg.us/indust/charcoal.htm
(Site Excerpt) During the summer 2000 field season at Scatness, some experimental
archaeology was carried out near the excavated Broch. A bloomery shaft furnace
was constructed from clay, and local bog iron ore was smelted. The furnace
filled with charcoal: bellows and tuyere at left, and thermocouple built into
furnace wall at front.
The North Yorkshire Moors Ironworking Project
http://www.rmsg.us/indust/charcoal.htm
(Site Excerpt) The North Yorkshire Moors have a history of iron working which
extends back to the Iron Age. Although modern industry has been studied in
detail for Rosedale and the Cleveland area, very little research has been
undertaken into the industry's origins. The western side of the North Yorkshire
Moors has several important sites linked to the different phases/periods of
English iron-smelting technology, focused around Rievaulx Abbey.
Old Rookhope Archive: History of Iron Mining
http://www.rmsg.us/indust/charcoal.htm
(Site Excerpt) Iron mining and smelting started in Weardale and Teesdale at
least as early as Roman times, as shown by the slag found on small native
British settlements. The earliest documented iron working in the Rookhope
Valley is a reference to iron mines in 1154 AD. Both Weardale and Teesdale
have abundant evidence for medieval iron smelting. Medieval smelting sites
called bloomeries left distinctive heaps of slag, many of which can be found
in the Durham Dales.
See also Smelting video:
http://www.pastperfect.org.uk/sites/oldrookhope/archive/43.html
This site provides a video of a medieval style smelting furnace complete with
bellows work. If you access the page, you will either see the video automatically
or get an error message. There is nothing else on the page. If you computer
loads slowly you may wish to avoid this page as there is no choice given for
viewing the video.
Smelting Silver
http://www.rocks4brains.com/~cat/SmeltingAg.pdf
An Excellent article in Adobe Acrobat on the subject.
Pewter Casting in Stone Molds
http://www.warehamforge.ca/pewter.html
(Site Excerpt) The majority of jewelry objects remaining from the Viking
Age are either made of silver or bronze. Silver is commonly found in massed
hordes, with coins, ingots, fragments forming the largest portion rather than
finished jewelry. These hordes are obviously collected wealth, hidden in times
of peril by owners who never returned. The common medium of exchange was obviously
silver, gold objects are relatively uncommon throughout Scandinavia. Although
simple sliver objects are found, many show a very high degree of craftsmanship.
Complex forming and assembling techniques are commonly seen with silver.
Sources for Pewterers in these Current Middle Ages
Being a list of sources compiled by the Honourable Sergeant Avery Austringer
http://home.i1.net/~avery/pewter_sources/pewter_sources.html
(Site Excerpt) The following is a slightly revised version of a handout which
I prepared for, Pewter Casting To Go, a class which Charles Oakley and I have
taught at Pennsic, in which we teach people how to make small pewter castings
and venerate Joe L'Erario and Ed Feldman. While I am one to encourage people
to try new things, please try them safely - liquid pewter is hotter than the
hottest thing you want to touch. It will bring water to a boil and much popping
and splattering will occur. Carving soapstone generates a lot of silicon rich
dust. The vapor over molten lead (if you use leaded pewter) is both toxic
and bioavailable. You can work with these materials safely or you can do yourself
grievous harm - it's up to you.
Stefan's Florilegium casting-msg
http://www.florilegium.org/files/CRAFTS/casting-msg.html
(Site Excerpt from one message) Beginning Pewter Casting by Lady Nicolaa de
Bracton of Leicester
Materials needed:
--Pewter (bar or chip form).
--heat source (propane torch, stovetop element, casting pot, campfire)
--Container to heat pewter in (small pot, ladle, etc.)
--material for mold (preferably soapstone)
--rubber bands
--carving tools (dental or woodcarving tools are best, but virtually
anything will carve soapstone)
--sandpaper
--files (microfiles are most useful)
--tongs or clamps
--bowl of cold water
--pliers
--towels or oven mitts
A note on pewter: Pewter sold today in craft stores for jewellery-making is
usually lead free; it is an alloy of copper, tin, and antimony. A number of
companies also sell pewter for miniature casting; this may not be lead-free.
If in doubt, ask. Current going price for one pound of lead-free pewter in
the Toronto area is $10-$17 CDN. Craft stores are often overpriced; ask your
local SCA jewellery - and metalworkers for sources.
CASTING SETS --WANT TO GET STARTED--FOR THE LOWEST COST?
http://www.miniaturemolds.com/casting.htm
(Site Excerpt) Each of our money saving Introductory Casting Set offers contain
the following:
(the sets differ from each other only in size of the melting pot)
*Melting Pot
*Figure Mold (your choice of a Medieval Knight, Civil War (figure can be painted
as either a Union or Confederate soldier), American Indian, Coldstream Guard
silicone rubber mold, or a 3 figure American Infantry WW2 action mold
*Ingot of casting metal (composition 10% Tin, 11% Antimony, 79% Lead). This
ingot will make 5 to 6 54mm (21/4") figures. You may substitute an ingot of
lead-free pewter for an additional $3.50.
*2 Mold Clamps ((when a rubber mold is selected or one metal clamp and a pair
of wood mold handles, when the metal mold is selected).
*Heavy Duty Gloves
*Complete Instructions
Midrealm Order of the Laurel Medieval Arts and Sciences Database: Casting
http://www.midlaurel.com/wsnlinks/index.php?action=displaycat&catid=196
Site lists several other sites and references for the art, and ranks them
according to reliability.
Pewter Casting Alloys: CARN METALS
Manufacturers of High Quality Tin Casting Alloys and Solders
http://www.carnmetl.demon.co.uk/index.htm
This page loads to a menu (farther down the page, otherwise it's almost blank)
that had the following options: Casting alloys, mould making, schools, help
with casting problemsasting alloys, mould making, schools, help with casting
problems; Stained glass work, electronics general jointing and construction
of pewter and whitemetals; Alloys, casting using, cleaning general info; properties
and uses, tin mining, early technology.
Blowing new life in old technology - Viking Age Metal-casting.
By Anders Söderberg.
http://www.frojel.com/Documents/Document02.html
(Site excerpt) Early medieval founders cast using technology with roots deep
in the Bronze Age. The process looked almost the same as it had done for a
couple thousand years. If the Bronze Age was the golden age of bronze casting,
the craft didn't die with the coming of iron. Casting in bronze and silver
still played an improtant social part through the production of jewellery
and prestige objects, a production of social codes expressing identity and
belonging; sworn fidelity and social ranking. All confirmed by a system of
gifts, sometimes almost strong enough to give each object a life of it's own;
at least this may have been the way contempory man regarded it. I have devoted
the last three years to examining some of these crafts in detail. I have worked
particularly with reconstructed bronze and silver casting, supportedby excavation
publications and earlier experimental projects. There have been many of them
in recent decades, with varying ambitions and results, but the most extensive
are probably the Danish and English. These projects are also the best documented.
Swedish Silver - Silver In The Middle Ages (circa 1050-1520) (An older Book
for Sale circa 1951)
http://www.oldandsold.com/articles03/silver24.shtml
(Site excerpt) In periods of strife, people buried silver, and many a rightful
owner did not live to unearth his fortune, which remained for centuries until
plow or spade happened to strike the treasure. A famous example is the Lohe
fortune, which lay hidden in the double floor of a Stockholm house for almost
two centuries, and came to light only when the house was razed in 1937. The
role of silver as heirloom and investment involved a strict system of guarantees
as to purity. In countries outside Sweden, hallmarks were issued as early
as the thirteenth century. In Sweden it was decreed in 1485 that gold- and
silversmiths should "put their mark on whatsoever they made." Duke Karl IX
in 1596 proclaimed that along with their marks, smiths should imprint the
insignia of their city arms on each piece.
Silver smithing Supplies--Silver Casting Grains and Cheap Clean Scrap Silver
(Retail Merchant/supplier)
http://www.ccsilver.com/silver/scastg.html
SRS Lost Wax and Stone Casting Supplies (Retail Merchant)
http://www.srs-ltd.co.uk/
Ancient History:
Cire Perdue: Lost Wax Casting (mainly about GOLD in Indonesia)
http://www.nusantara.com/heritage/wax.html
(Site excerpt) Gold has always been an important medium of expression for
Javanese craftsmen. In prehistoric times, gold-foil masks were used to cover
the faces of the dead. These gold pieces were made by beating the gold with
a hammer. While this technique was widely used in various parts of Indonesia
and Southeast Asia, a more effective technique was adopted in Java during
the early centuries AD, whereby heat was used to work gold. This new method
not only cuts down the time spent in making gold objects, but is also responsible
for the creation of more intricate designs. The technique is known as lost
wax casting. Click on the red buttons to see an illustration of each stage
of the lostwax casting process.....
Scandinavian bronzecasting in Viking Age and Early Middle Ages
Anders Söderberg
http://members.chello.se/vikingbronze/casting.htm
(Site Excerpt) Bronze casting is an elegant play with a couple of cubic-decimeters
of borrowed hell. It´s quite handy as it´s limited to a small pit, but deceptive
as you easily could be seduced to think you´re its master. Who´s terms you´re
working under is obvious each time you accidently put your thumb too close
to the hearth, or when you in distraction almost grips the crucible with your
fingers. These things bite, and they bite bad... Early medieval casting had
deep traditions since Bronze Age. The Viking Age process probably looked quite
the same as it already had done for a couple of thousand years. If Bronze
Age was the golden age of bronze casting, the craft didn´t die with the coming
of iron. Metal casting still played an important social part by the production
of jewellery and prestige objects, a production of social codes telling about
identity and belonging, of sworn fidelity and of alliances. All confirmed
by a system of giftgiving, almost strong enough to give each object a life
of its own; at least this may have been the way contemporary man regarded
it.
Viking Bronze: Blowing new life into Ancient and Early Medieval Metalcraft
http://members.chello.se/vikingbronze/vikingbronze.htm
(Site Excerpt) This page deals with ancient metalcraft and research mainly
from a reconstructional and experimental basis. The page will provide texts,
resources and links related to the archaeology of ancient and early historic
metalcrafts. The Iron Age/early Middle Age founders cast in techniques with
roots deep down in Bronze Age and the methods presented here could, with slight
adjustments, be said to be relevant for all the Scandinavian Iron Age and
up into the Middle Ages.
ORB:
Medieval Iron and Steel -- Simplified by Bert Hall
Institute for the History and Philosophy of Science and Technology, University
of Toronto
http://www.the-orb.net/encyclop/culture/scitech/iron_steel.html
(Site Excerpt) Pure, unadulterated iron is only moderately hard, as anyone
who has bent a nail with a hammer can attest. When it becomes red hot, say
at about 700 degrees Celsius, it can be easily bent and formed into whatever
shape the artisan wishes -- straps, hinges, horseshoes. For this reason we
speak of "wrought iron," (wrought, from wreak, to bend or twist). Unfortunately,
it is also only moderately tough; it can easily be bent when being used. It
also loses any sharp edge very quickly under the pressure of work or abrasion.Cast
iron, on the other hand, is enormously strong. Cast iron takes its name from
the fact that it emerges from the smelter in liquid form (see below) and can
be cast into moulds rather like bronze or silver. Unfortunately, it is rather
brittle, and worse, it can't be bent or shaped in any way once it has solidified.
Hammering on red hot, even white hot, cast iron will simply break it. Steel,
iron with a small amount of carbon dissolved inside its structure, combines
the best of both worlds. It can be cast into moulds from the furnace, shaped
when red hot, and it holds an edge when it has been sharpened, even under
fairly heavy use. Steel is clearly the prince of ferric metals, but it's not
easy to make.
Cauldrons and the Development of Cast Iron for Domestic Use
By: Jacob Selmer
Last revised: 10/31/2003
http://filebox.vt.edu/users/jselmer/cauldrons.htm
(Site Excerpt) The study of early metallurgy and metalworking often focuses
on military and industrial applications. However, the everyday uses of metals
are sometimes overlooked. In particular, the cauldron played an essential
role in day-to-day life. Modernly, manufacturers make these out of cast iron,
but Europeans did not begin using this material until early in the fifteenth
century and mass production of cast iron did not happen until the eighteenth
century. This report discusses some of the history and importance of cauldrons
and focuses on the development of cast iron for everyday use.Celtic cauldrons:
Cauldrons in Celtic life played an important role. More than just essential
cooking vessels, they could also have magical qualities attributed to them.
Cauldrons and chalices appear in many Celtic tales and rituals. Early Celtic
metalworkers generally crafted these cauldrons from brass or bronze, which
they either cast into a single piece or forged in multiple pieces and joined
with rivets and solder. Archaeologists found one such cauldron at Gundstrup,
Denmark (Figure 1). This highly decorated vessel from the first century B.C.
consists of thirteen silver gilt panels, combining to create a 27-inch diameter
cauldron (Lang, 83-85, Eluere, 116-117). The expense of Celtic cauldrons made
them unaffordable for most people and consequently, the craftsmen often took
great care to make them works of art.
Arch-Metals Archaeo-Metallurgical Bibliography
INDEX
http://users.ox.ac.uk/~salter/arch-metals/met-index.htm