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.
Dame Aoife Finn of Ynos Mon, OL
Accounts of Tin Mining in Cornwall,
Stanner Charters of 1198 & 1201
(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
(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)
(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
(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
(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
(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
(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
(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
(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:
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.
An Excellent article in Adobe Acrobat on the subject.
Pewter Casting in Stone Molds
(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
(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
(Site Excerpt from one message) Beginning Pewter Casting by Lady Nicolaa de Bracton of Leicester
--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)
--carving tools (dental or woodcarving tools are best, but virtually
anything will carve soapstone)
--files (microfiles are most useful)
--tongs or clamps
--bowl of cold water
--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?
(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)
*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
Midrealm Order of the Laurel Medieval Arts and Sciences Database: Casting
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
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.
(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)
(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)
SRS Lost Wax and Stone Casting Supplies (Retail Merchant)
Cire Perdue: Lost Wax Casting (mainly about GOLD in Indonesia)
(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
(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
(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.
Medieval Iron and Steel -- Simplified by Bert Hall
Institute for the History and Philosophy of Science and Technology, University of Toronto
(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
(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