Plans have been changed, which has caused this break in activity. This project was to be my entry in the Hordweard challenge, but it turns out that a couple of people have had to drop out and there were not going to be any other entrants ready to complete their challenges. I spoke with the organiser and we arranged to adjust the challenge dates to accommodate some other entrants. The new Hordweard challenge will be taking boasts (a vocalisation of your intended personal challenge) at Spring War (in the Hunter Region, New South Wales, Australia), this weekend. People will have to put their contributions into the hord (donations to the prize) and complete all challenges before October 20. Entrants will present their research and finished pieces at Rowany Festival (Sydney, NSW Australia) , Easter 2014. That gives new entrants 6 months to work on their pieces.
When this seemed to be the case, earlier in the year, I stopped working on my entry so it wouldn't have 12 months of extra work in it. I won't start to work on it seriously again until after November. That way, there will be about 6 months of actual work in it. I started researching after Spring War (October 2012), and stopped when I moved in December 2012. There was only one other entrant, so things petered off. We now have at least 2 others who will be challenging this weekend, so it is on again!
Monday, 30 September 2013
Tuesday, 25 June 2013
Swamimalai casting workshop film
So... after that post saying I was pretty much ready to admit a permanent break on this project, it seems things are moving again.
This short film shows a bronze casting workshop in Indian that is using the lost wax technique.
https://www.youtube.com/watch?
It has some fairly amazing modern images of methods that seem unchanged through time. I especially like the giant foundry tongs that are used by 2 men to pick up the vessel of molten metal. I'm now super excited to make some models. We have a big event coming up in a week and a half: Lochac Midwinter Coronation. After that there should be time to spend on this. Back on board!
This short film shows a bronze casting workshop in Indian that is using the lost wax technique.
https://www.youtube.com/watch?
It has some fairly amazing modern images of methods that seem unchanged through time. I especially like the giant foundry tongs that are used by 2 men to pick up the vessel of molten metal. I'm now super excited to make some models. We have a big event coming up in a week and a half: Lochac Midwinter Coronation. After that there should be time to spend on this. Back on board!
Friday, 14 June 2013
Hiatus
Hello there. I have not posted for quite some time, as other projects have been pushed up the list and the event that this project was to be presented at has not been planned to run. I have really enjoyed this topic and will get back to some study at some point but it is not likely to be soon.
Check back in a towards the end of 2013.
See you then :)
Heilwich
Check back in a towards the end of 2013.
See you then :)
Heilwich
Monday, 10 December 2012
The many articles of Anders Soderberg
http://web.comhem.se/vikingbronze/
Yet another site where Anders pops up. This is his website, including a short explanation of his motivation as an experimental archaeologist, a great visual record of his use of cire perdue to cast replicas of items found at Birka, and a few of his articles. He has a lot. Thanks Anders, for recording your findings so clearly.
An excellent quote that evokes emotions around why we do what we do:
'The sintered ware is stable and hardy and after being digged-up and washed, a viking age crucible looks the same today; just the way it looked when cooling-off at the workshop's floor a thousand years ago. Even Bronze-Age crucibles haven't changed very much, despite the passing of three thousand years. This gives a perspective on time. It's a strong reminder, of thousand or three thousand years being no more than a snap with your fingers in the universe. '
Yet another site where Anders pops up. This is his website, including a short explanation of his motivation as an experimental archaeologist, a great visual record of his use of cire perdue to cast replicas of items found at Birka, and a few of his articles. He has a lot. Thanks Anders, for recording your findings so clearly.
Article - Scandanavian bronzecasting the the Viking Age and Early Middle Ages
This article is almost identical to another website of Anders', though I like the way this one is found on a links section on the main page of his site.
'The sintered ware is stable and hardy and after being digged-up and washed, a viking age crucible looks the same today; just the way it looked when cooling-off at the workshop's floor a thousand years ago. Even Bronze-Age crucibles haven't changed very much, despite the passing of three thousand years. This gives a perspective on time. It's a strong reminder, of thousand or three thousand years being no more than a snap with your fingers in the universe. '
Anders Soderberg
This article has a very useful map showing the location of 9 Viking Age metalwork sites and quite a few images of extant and recreated in ground furnaces, complete with equipment for bronze casting. He also discusses the difficulties of pouring into clay moulds made from Scandanvian glacial and post glacial clays, which he says contain significant quantities of lime, which produce gas on heating.
Anders says that if you have 5mm walls on your clay mould, it will take around a quarter of an hour to heat it up to 700 degrees C in an unbellowed furnace. He also says that you have around 20 seconds between removing the mould from the fire and significant cooling that will affect the casting process. This is useful because all sources so far agree that the best results for cire perdue casting take place when the clay mould is not only prefired, whilst the clay is removed, but refired/preheated simlutaneously to the heating of the metal in the crucible. This theory is supported by the existence of dual in ground furnaces.
Article - Reconstructing the Trundholm Sun Chariot
This document outlines the process needed to complete a statue of a chariot with wheels and horse. It is outside the period I am looking into for this project but is fascinating, none the less. It is especially interesting to note that he says the horse sculpture is cast around a clay core. I am keen to find out if this means the clay core remains in the object. Wouldn't that mean it would have to float free during casting? Or could it be held in place with plugs that do not show up on the finished item? Perhaps it just means a clay mould was used in the core of the sculpture, not to remain after casting.
Anyway, Anders also discusses the shrinkage rates of bronze and clay on firing. He suggests that it would be usual to expect between 2.8 - 5.6%. More sand in the moulding clay makes a stronger mould but gives a higher % of shrinkage.
Anders says he has grown used to working in beeswax, despite modern claims of it being too sticky. He puts time into polishing the wax model before making the mould, as it reduces the amount of time needed to clean up the cast item.
There is also a detailed explanation of how to apply the clay mould to get a good transfer of the original details.
Article - Scandanavian Iron Age and Early Medieval Ceramic Moulds - Lost Wax or not or both?
Apparently the only sideways proof of the use of the cire perdue method in VA casting is the presence of a bar of wax amongst other casting tools in the burial of
'...a Viking goldsmiths' grave from Mysen in south east Norway. A man was found buried accompanied by crucibles, moulds and a piece of wax (Skjølsvold 1951). An archaeological problem with use of wax in casting, is that most of the wax used would have burnt away when firing the moulds. It disappears rather than being preserved in the soil, except for possibly in a few lucky cases.'
It has been hypothesised that wax and clay can be used in an array of combinations to produce models and moulds, including:
*a metal model (finished item) - pushed into a clay mould - cast from the original clay mould using an open mould
*a metal model - pushed into two open clay moulds that are joined by a fine slip - metal cast into void of clay moulds with natural cracking along the mould join
*a metal model (finished item) - pushed into a clay mould - cast from the original clay mould using an 2 part mould to allow gases to escape during casting
*a metal item - pushed into clay -one sided wax models made from clay mould - wax models used to make more open clay moulds - metal cast into replicated moulds
*a wax model - pushed into a clay mould - wax removed - metal cast into void of clay moulds
*a wax model - pushed into two open clay moulds that are joined by a fine slip - wax removed - metal cast into void of clay moulds with natural cracking along the mould join
This does not even begin to address the question of the elk horn and stone moulds found at the Birka site. There are many options.
A useful tip is the suggestion that a fine layer of oil on the surface of a metal model (finished piece of jewellery used to imprint upon clay to make a mould) can help it be removed more easily. This is relevant to the wax-copy technique.
There seems to some fair points made in the discussion on the advantages of the wax copy method over the direct matrix method - a metal model would be a valuable item of jewellery and it seems that being able to make as many wax copies as possible in a short a time as possible would be a major drawcard. Scenario 1: smith borrows, hires or is lent a piece of jewellery to make copies of on commission. The owner will want it back in their posession as soon as possible. Scenario 2: the smith is working for a very wealthy person who owns many pieces. The smith 'liberates' the item for a half hour to make a mould, making time a valuable commodity. Scenario 3: I am thinking about this on a modern 21st Century view of time use. Our current view of getting things done fast has been accelerated by telecommunications and high speed travel. Perhaps a couple of extra weeks to complete some extra moulds was not a big issue.
There are quite a few more articles to go, including a new journal to look at.
Sunday, 2 December 2012
update: pot bellows from Tell edh-Dhaba'i
There was also a pipe made from clay in the finds, presumably to get air from the bellows to the charcoal burn face. I don't know if it was a matched diameter or how it was attached.
And a quote I like,
'A transfer of ideas was not in one direction only...' (p.14). Makes a nice counter point to the concept that ideas do not simply bleed into adjacent cultures, even when contact and similar levels of technology are available.
And now it is time to stop reading this article. I would love to find an article just like this for the 10th C Norse cultures and their geographical and trading partners. Must keep looking.
And a quote I like,
'A transfer of ideas was not in one direction only...' (p.14). Makes a nice counter point to the concept that ideas do not simply bleed into adjacent cultures, even when contact and similar levels of technology are available.
And now it is time to stop reading this article. I would love to find an article just like this for the 10th C Norse cultures and their geographical and trading partners. Must keep looking.
Article: The Metal Worker's Tools from Tell Edh Dhiba'i
Summary
This article looks at tools found in a workshop that was active around 2500 BC in Sumer, in the same area as the modern suburbs of Baghdad. This article, written by Christopher Davey, was an extract from the Bulletin of the Institute of Archaeology, University of London, 20, 1983. This article has some excellent images, including extant pieces and ancient images of the smithing process. It was found at www.aiarch.org.au on November 17th, 2012.
Metal workshop
The workshop in question belonged to a copper smith who also worked in alloys i.e. bronze. This is evident from the traces of copper, tin, iron and nickel that were found inside a used crucible. Several crucibles, moulds and bellows were found, constructed from a variety of clays.
Crucibles
The crucibles found at the Tell edh-Dhiba'i workshop were shaped like a curved funnel with a large opening at the top and a tear drop shaped opening on the side of the bottom, unlike the 'open crucibles of the Levant, Anatolia and Iran (Tylecote, 1976: 20)'. This shows that, including the open crucible common to the region and similar to the open crucible used at Birka in the 9th and 10th centuries, the curved crucible used in ancient Egypt and Mesopotamia, the lidded Migration Era crucible, and the bowl form with a hole in the side found in Keos, Byblos and Sinai (Dunand: 1958; Petrie: 1906), there were numerous functional designs for crucibles that have been used through out history and around the world.
The author describes the fabrication of the crucibles thus:
'The fabric of the crucibles was fairly coarse containing silica and having holes left by straw which was consumed during firing. It was estimated that the vessels were fired to around 800 degrees Celcius and the exterior of the unused crucible seems to indicate that towards the end of the firing they were subjected to oxidising conditions
These crucibles were 'subjected to repeated applications of high temperatures' (p. 6), leaving the portion that was closest to the heat 'white and friable.'
"A total of five crucibles and one fragment of a crucible were found at Tell edh Dhiba'i. Their condition varies from good in the case of the unused crucible 8 to very fragile for those at the end of their operational life.' (p.2)
This suggests that is was normal to use crucibles more than once before they surcame to structural deterioration due to heat exposure, but also that crucibles were not used for so long that it was unusual to have back ups ready to go in the workshop.
Another factor that indicates that crucibles were reasonably disposable was the use of a mould to create their shape. If a crucible lasted for a year, it may be unusual for a workshop to have a specific mould on hand to create new crucibles. The presence of a moulds and indication of mould use in shaping indicate that crucibles were a high-turnover smithing tool.
'The crucibles are very similar size and shape and in fact crucibles 7 and 4 are almost identical as are crucible 8 and fragment 5. The remaining two crucibles were slightly larger than the others. The uniformity would suggest that the crucibles were made by hand with the aid of a concave mould which formed the basic curve.' (p.2)
This also indicates that crucibles were made on site, and a crucible mould could be considered a plausible part of a metal smith's tool kit.
Moulds
Also amongst the finds were some open moulds used for casting ingots (either bar or ring, as was popular a the time). After taking cultural and time differences into account, a form of a mould for recasting metal for trade may be considered a plausible tool for a metal smith. The site at Tell edh-Dhiba-i is distinct because it belonged to a smith who 'did not use stone moulds common to the Levant and Northern Mesopotamia (Davey 1977).'
Another kind of mould may be of even more relevence to building the concept of a metal smith's shop in Birka.
'Object 19 was identified as a cire perdue mould... The mould was made from two distinctly different types of clay; the inner cylinder surrounding the pin of fine yellow clay and an outer shell of coarser buff-coloured clay. The bottom of the mould has been broken although it appears not to the extent neccesary to extract the pin. The mould was therefore unused. The unbroken end of the mould is funnel-shaped, indicating that it was placed in or by the furnace in an upright position with the funnel end uppermost.' (p.10)
The article says that cire perdue has been used since atleast 4000BC (de Jesus, 1980; Hunt 1980; Lucas, p.10). The moulds appear to be rare finds prior to Roman times, though the author states the method was widely used in a variety of cultures including Roman, Indian, Sumerian, Bablyonian and Egyptian.
Cire perdue method
'A fine slurry was initially applied to a wax model and after it had dried a second coat of fine clay was added. Finally, a third layer of coarser clay was added to strengthen and protect the mould' (p.10).
The author states that this method has been used in India since ancient times right through to today.
Sand casting
Among the finds was a clay model of an axe head, used to impress a shape into sand or clay, with molten metal being cast into the cavity. The model has a hole for a rod to aid removal from the moulding material, set at a 45 degree angle.
'It is generally believed that sand casting commonly used in foundries today was a technique developed in the 18th century AD (Tylecote 1962: 110). Theophilus, however, described the use of clay as a casting medium in the 11 th century AD (Hendry 1847: 313, Agricola, 1950: 405, 536).
The Biblical description of the manufacture of the bronze objects for the temple of Soloman states that it was executed by a metalworker from Tyre who cast them 'in the compactness of the soil' (1 Kings 7: 46). This is generally translated as 'in the clay ground' (Revised version) although the Jerusalum Bible actually refers to 'sand casting'. The Bedouin today...have a tradition of using loose earth for casting (Weir, 1976: 67) and there is no reason why metal workers during the Old Babylonian period could not also manufacture a waterless, sand-clay mixture into suitable material for casting.' (p.12)
Furnace
The article suggest that the furnace would have been 'sunk into the ground so as to provide maximum insulation' (p.13) and also suggests that multiple crucibles may have been heated at once (p.14) - the Egyptian Old Kingdom symbol for copper is very similar to two curved crucible sitting back to back (p.7). The reliefs found in the Egyptian tomb of Mereruka, Saqqara from the Fifth Dynasty and in the Mastaba of Wep-em-nefert at Giza show:
...'that melting is performed in two crucibles placed back to back and with six men using blowpipes aimed at the charcoal placed in front of each crucible. After the metal was melted, the crucible was taken to the mould, held with the assistance of two stones or lumps of clay and then a blockage in the mouth of the crucible was removed to allow the metal to discharge into the mould.' (p.6)
These furnaces are shown in the ground. The Egyptian furnaces are shown being assisted by mouth belows. Pot belows were found at Tell edh Dibha'i, just 2, hand formed. The author suggests they could be operated by foot. They were made from 'medium fine clay' heated to 500 degrees Celcius, measuring '0.45m in diameter and 0.16m high' (p.2). I need to look into these further, though they have an obvious lip around the top, which would allow a bladder or cover to be secured. A one and a half inch pipe sticks out for two inches at the base of one side, with a small channel, 2/3rds of an inch in diameter running, presumably into the vacant belly of the pot. The whole pot has a very flat base, giving it a sturdy appearence.
The share of casting technology and knowledge
Many parallels are drawn between ancient Egyptian and Mesopotamian (where the dig site was located) metal working techniques. These techniques are not shared with some of their near trading partners {Anatolia, Iran and the coast of Levant}, however, even where one culture traded metals with another, or was in a position of control over the other region for a significant period of time (p. 14). The author postulates that this was because of the differences in fuel availability. This is an example of how neighbouring cultures can continue on parallel but distinct technique paths, without the 'information bleed' that we often assume as recreationists. Just because a neighbouring, trading culture had a technique, does not mean the metalsmiths of a region picked up.
Relevance to metal smiths in 10th Century Birka
I believe that where I cannot find sufficient information to pin down a technique, it would be plausible to draw from these ancient techniques, since many of these tools and methods are still in use to this day, in a wide variety of locations and cultures around the world. I can document the presence of a table top furnace from Baghdad in Scandanavia several centuries before Birka. It may well have been used or admired by several generations of Norsemen until it was laid where it was found in modern times. Since there was trade with the peoples of the Near and Far East, I think it is plausible to draw on techniques that were used amongst these cultures, where I am unable to discover the exact method used to create the pieces in a 10th century Birka metalsmiths workshop.
This article looks at tools found in a workshop that was active around 2500 BC in Sumer, in the same area as the modern suburbs of Baghdad. This article, written by Christopher Davey, was an extract from the Bulletin of the Institute of Archaeology, University of London, 20, 1983. This article has some excellent images, including extant pieces and ancient images of the smithing process. It was found at www.aiarch.org.au on November 17th, 2012.
Metal workshop
The workshop in question belonged to a copper smith who also worked in alloys i.e. bronze. This is evident from the traces of copper, tin, iron and nickel that were found inside a used crucible. Several crucibles, moulds and bellows were found, constructed from a variety of clays.
Crucibles
The crucibles found at the Tell edh-Dhiba'i workshop were shaped like a curved funnel with a large opening at the top and a tear drop shaped opening on the side of the bottom, unlike the 'open crucibles of the Levant, Anatolia and Iran (Tylecote, 1976: 20)'. This shows that, including the open crucible common to the region and similar to the open crucible used at Birka in the 9th and 10th centuries, the curved crucible used in ancient Egypt and Mesopotamia, the lidded Migration Era crucible, and the bowl form with a hole in the side found in Keos, Byblos and Sinai (Dunand: 1958; Petrie: 1906), there were numerous functional designs for crucibles that have been used through out history and around the world.
The author describes the fabrication of the crucibles thus:
'The fabric of the crucibles was fairly coarse containing silica and having holes left by straw which was consumed during firing. It was estimated that the vessels were fired to around 800 degrees Celcius and the exterior of the unused crucible seems to indicate that towards the end of the firing they were subjected to oxidising conditions
These crucibles were 'subjected to repeated applications of high temperatures' (p. 6), leaving the portion that was closest to the heat 'white and friable.'
"A total of five crucibles and one fragment of a crucible were found at Tell edh Dhiba'i. Their condition varies from good in the case of the unused crucible 8 to very fragile for those at the end of their operational life.' (p.2)
This suggests that is was normal to use crucibles more than once before they surcame to structural deterioration due to heat exposure, but also that crucibles were not used for so long that it was unusual to have back ups ready to go in the workshop.
Another factor that indicates that crucibles were reasonably disposable was the use of a mould to create their shape. If a crucible lasted for a year, it may be unusual for a workshop to have a specific mould on hand to create new crucibles. The presence of a moulds and indication of mould use in shaping indicate that crucibles were a high-turnover smithing tool.
'The crucibles are very similar size and shape and in fact crucibles 7 and 4 are almost identical as are crucible 8 and fragment 5. The remaining two crucibles were slightly larger than the others. The uniformity would suggest that the crucibles were made by hand with the aid of a concave mould which formed the basic curve.' (p.2)
This also indicates that crucibles were made on site, and a crucible mould could be considered a plausible part of a metal smith's tool kit.
Moulds
Also amongst the finds were some open moulds used for casting ingots (either bar or ring, as was popular a the time). After taking cultural and time differences into account, a form of a mould for recasting metal for trade may be considered a plausible tool for a metal smith. The site at Tell edh-Dhiba-i is distinct because it belonged to a smith who 'did not use stone moulds common to the Levant and Northern Mesopotamia (Davey 1977).'
Another kind of mould may be of even more relevence to building the concept of a metal smith's shop in Birka.
'Object 19 was identified as a cire perdue mould... The mould was made from two distinctly different types of clay; the inner cylinder surrounding the pin of fine yellow clay and an outer shell of coarser buff-coloured clay. The bottom of the mould has been broken although it appears not to the extent neccesary to extract the pin. The mould was therefore unused. The unbroken end of the mould is funnel-shaped, indicating that it was placed in or by the furnace in an upright position with the funnel end uppermost.' (p.10)
The article says that cire perdue has been used since atleast 4000BC (de Jesus, 1980; Hunt 1980; Lucas, p.10). The moulds appear to be rare finds prior to Roman times, though the author states the method was widely used in a variety of cultures including Roman, Indian, Sumerian, Bablyonian and Egyptian.
Cire perdue method
'A fine slurry was initially applied to a wax model and after it had dried a second coat of fine clay was added. Finally, a third layer of coarser clay was added to strengthen and protect the mould' (p.10).
The author states that this method has been used in India since ancient times right through to today.
Sand casting
Among the finds was a clay model of an axe head, used to impress a shape into sand or clay, with molten metal being cast into the cavity. The model has a hole for a rod to aid removal from the moulding material, set at a 45 degree angle.
'It is generally believed that sand casting commonly used in foundries today was a technique developed in the 18th century AD (Tylecote 1962: 110). Theophilus, however, described the use of clay as a casting medium in the 11 th century AD (Hendry 1847: 313, Agricola, 1950: 405, 536).
The Biblical description of the manufacture of the bronze objects for the temple of Soloman states that it was executed by a metalworker from Tyre who cast them 'in the compactness of the soil' (1 Kings 7: 46). This is generally translated as 'in the clay ground' (Revised version) although the Jerusalum Bible actually refers to 'sand casting'. The Bedouin today...have a tradition of using loose earth for casting (Weir, 1976: 67) and there is no reason why metal workers during the Old Babylonian period could not also manufacture a waterless, sand-clay mixture into suitable material for casting.' (p.12)
Furnace
The article suggest that the furnace would have been 'sunk into the ground so as to provide maximum insulation' (p.13) and also suggests that multiple crucibles may have been heated at once (p.14) - the Egyptian Old Kingdom symbol for copper is very similar to two curved crucible sitting back to back (p.7). The reliefs found in the Egyptian tomb of Mereruka, Saqqara from the Fifth Dynasty and in the Mastaba of Wep-em-nefert at Giza show:
...'that melting is performed in two crucibles placed back to back and with six men using blowpipes aimed at the charcoal placed in front of each crucible. After the metal was melted, the crucible was taken to the mould, held with the assistance of two stones or lumps of clay and then a blockage in the mouth of the crucible was removed to allow the metal to discharge into the mould.' (p.6)
These furnaces are shown in the ground. The Egyptian furnaces are shown being assisted by mouth belows. Pot belows were found at Tell edh Dibha'i, just 2, hand formed. The author suggests they could be operated by foot. They were made from 'medium fine clay' heated to 500 degrees Celcius, measuring '0.45m in diameter and 0.16m high' (p.2). I need to look into these further, though they have an obvious lip around the top, which would allow a bladder or cover to be secured. A one and a half inch pipe sticks out for two inches at the base of one side, with a small channel, 2/3rds of an inch in diameter running, presumably into the vacant belly of the pot. The whole pot has a very flat base, giving it a sturdy appearence.
The share of casting technology and knowledge
Many parallels are drawn between ancient Egyptian and Mesopotamian (where the dig site was located) metal working techniques. These techniques are not shared with some of their near trading partners {Anatolia, Iran and the coast of Levant}, however, even where one culture traded metals with another, or was in a position of control over the other region for a significant period of time (p. 14). The author postulates that this was because of the differences in fuel availability. This is an example of how neighbouring cultures can continue on parallel but distinct technique paths, without the 'information bleed' that we often assume as recreationists. Just because a neighbouring, trading culture had a technique, does not mean the metalsmiths of a region picked up.
Relevance to metal smiths in 10th Century Birka
I believe that where I cannot find sufficient information to pin down a technique, it would be plausible to draw from these ancient techniques, since many of these tools and methods are still in use to this day, in a wide variety of locations and cultures around the world. I can document the presence of a table top furnace from Baghdad in Scandanavia several centuries before Birka. It may well have been used or admired by several generations of Norsemen until it was laid where it was found in modern times. Since there was trade with the peoples of the Near and Far East, I think it is plausible to draw on techniques that were used amongst these cultures, where I am unable to discover the exact method used to create the pieces in a 10th century Birka metalsmiths workshop.
Thursday, 15 November 2012
Sourcing bronze for casting
Over the last couple of days people on the Norsefolk list have been talking about bronze for buckles.
Someone pointed out that since the exclusion of lead from most freely available items, plumbing solder is now almost exusively tin. He says he has taken 98% tin solder and combined it with stripped-back copper wiring in the necessary proportion (85:15?), melted it in a ceramic crucible using two propane torches and produced bronze for casting.
Another person from the list says he finds is much more sure to make a one off wax model and send it to a casting house to have the item made than to try to cast the items himself and lose the wax model.
They are both ideas worth investigating. Since I am focussing in on the model and mould making, I probably won't have time to also learn about the casting side of things during this challenge. A cast item would be nice to have at the end, instead of just a series of wax lumps.
Someone pointed out that since the exclusion of lead from most freely available items, plumbing solder is now almost exusively tin. He says he has taken 98% tin solder and combined it with stripped-back copper wiring in the necessary proportion (85:15?), melted it in a ceramic crucible using two propane torches and produced bronze for casting.
Another person from the list says he finds is much more sure to make a one off wax model and send it to a casting house to have the item made than to try to cast the items himself and lose the wax model.
They are both ideas worth investigating. Since I am focussing in on the model and mould making, I probably won't have time to also learn about the casting side of things during this challenge. A cast item would be nice to have at the end, instead of just a series of wax lumps.
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