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Post by tsmspace on Apr 4, 2020 23:38:23 GMT
Ok, surviving artifacts are basically cast.
the story goes, you don't really benefit from forging the bronze, and with a nice set up you can cast a lot of weapons, so they were cast right along with the multitude of other tools and parts to be made from bronze during the era. it makes sense that weapons would have been cast because casting would have been much more common than making weapons, so making a weapons cast would have been very easy.
right but just because we don't have the artifacts, doesn't it make sense that actually I mean copper isn't pure it's already some kind of bronze just like iron isn't pure it's already some kind of steel,,,, we are talking about potentially 10,000 years but realistically still thousands of years from the start of copper use to the artifacts we have of cast bronze swords,,,
if you forge a bar and then pound out a sword, you will end up that if you flatten the end of it it makes a leaf. yet that is not a part of history/theory??
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Post by Timo Nieminen on Apr 5, 2020 0:42:26 GMT
You wouldn't bother to forge the bar, whether copper or bronze. Rather than casting, e.g., a hemispherical ingot, and then forging the bar from it, it's easier to just cast a bar in the first place. Similarly, if you want a leaf-blade, you can just cast it in the first place. Forging it from a bar just increases the chances of defects such as cracks, and will use more fuel since you'll have to keep annealing the piece when it work-hardens. The forged copper blades out there, restricted to the few places where native copper was available in sufficiently large pieces (sometimes with imported smelted copper used in the same way as native copper), are typically stabbing daggers. Generally, leaf-blades are relatively poor stabbers, and these copper daggers/swords used a stabbing geometry rather than a leaf-blade. You will, of course, recall the examples from the discussion in sbg-sword-forum.forums.net/thread/59434/grew |
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Post by tsmspace on Apr 5, 2020 7:55:48 GMT
You wouldn't bother to forge the bar, whether copper or bronze. Rather than casting, e.g., a hemispherical ingot, and then forging the bar from it, it's easier to just cast a bar in the first place. Similarly, if you want a leaf-blade, you can just cast it in the first place. Forging it from a bar just increases the chances of defects such as cracks, and will use more fuel since you'll have to keep annealing the piece when it work-hardens. The forged copper blades out there, restricted to the few places where native copper was available in sufficiently large pieces (sometimes with imported smelted copper used in the same way as native copper), are typically stabbing daggers. Generally, leaf-blades are relatively poor stabbers, and these copper daggers/swords used a stabbing geometry rather than a leaf-blade. You will, of course, recall the examples from the discussion in sbg-sword-forum.forums.net/thread/59434/grewthen again casting is hard, isn't it?? I mean, you need a lot of equipment, and then to work with literally liquid metal that flows like water. It seems to me like you would find it just easier to work with the ingots that form from the initial smelt,,,, and the longer ago we are talking about the better the ore, and closer to "native metal" we would be talking about. Just because a few thousand years after the copper age began, there wasn't surface native metal around doesn't mean there never was. |
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Post by Timo Nieminen on Apr 5, 2020 10:41:30 GMT
then again casting is hard, isn't it?? I mean, you need a lot of equipment, and then to work with literally liquid metal that flows like water. It seems to me like you would find it just easier to work with the ingots that form from the initial smelt,,,, Casting isn't going to be much harder than smelting, and is perhaps easier. The melting point of copper is lower than the temperature needed for smelting, and the melting point of bronze is even lower. Once people had furnaces good enough for smelting, they had furnaces more than good enough for bronze casting. Other than the furnace, you don't need high-tech for casting. The popularity of casting over forging for things that could be cast says something about which is easier. People who did this in the past weren't idiots - they did what worked well and easily. Forging was common for producing thin sheets, fine wires, etc. These are difficult to cast, so they were usually forged instead. Iron and steel are the other way around. The melting point of iron and steel is higher than the temperature needed for smelting, and difficult to reach with a primitive furnace. So iron/steel things were forged. Not always by choice, but because casting wasn't possible. (The melting point of cast iron is lower, but cast iron suffers from brittleness.) and the longer ago we are talking about the better the ore, and closer to "native metal" we would be talking about. No. Copper ores are chemical compounds of copper, either sulphides or carbonates (which are converted to oxides by roasting) or oxides. Chemistry now is the same as chemistry 10,000 years ago, so copper ores back then were basically the same as copper ores now. The main difference is that surface outcrops where the ore could be collected without deep mining and/or hard-rock mining were exhausted long ago. Just because a few thousand years after the copper age began, there wasn't surface native metal around doesn't mean there never was. We know that there was. Alas, in most places, the pieces of native copper were too small to make swords from. |
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Post by tsmspace on Apr 5, 2020 19:11:28 GMT
then again casting is hard, isn't it?? I mean, you need a lot of equipment, and then to work with literally liquid metal that flows like water. It seems to me like you would find it just easier to work with the ingots that form from the initial smelt,,,, Casting isn't going to be much harder than smelting, and is perhaps easier. The melting point of copper is lower than the temperature needed for smelting, and the melting point of bronze is even lower. Once people had furnaces good enough for smelting, they had furnaces more than good enough for bronze casting. Other than the furnace, you don't need high-tech for casting. The popularity of casting over forging for things that could be cast says something about which is easier. People who did this in the past weren't idiots - they did what worked well and easily. Forging was common for producing thin sheets, fine wires, etc. These are difficult to cast, so they were usually forged instead. Iron and steel are the other way around. The melting point of iron and steel is higher than the temperature needed for smelting, and difficult to reach with a primitive furnace. So iron/steel things were forged. Not always by choice, but because casting wasn't possible. (The melting point of cast iron is lower, but cast iron suffers from brittleness.) and the longer ago we are talking about the better the ore, and closer to "native metal" we would be talking about. No. Copper ores are chemical compounds of copper, either sulphides or carbonates (which are converted to oxides by roasting) or oxides. Chemistry now is the same as chemistry 10,000 years ago, so copper ores back then were basically the same as copper ores now. The main difference is that surface outcrops where the ore could be collected without deep mining and/or hard-rock mining were exhausted long ago. Just because a few thousand years after the copper age began, there wasn't surface native metal around doesn't mean there never was. We know that there was. Alas, in most places, the pieces of native copper were too small to make swords from. So then, the years of surface mining that took place would not have depleted surface formations in any way, and even today I should be able to go to the copper mines and find naturally exposed native metals? And the discovery of such metals probably coincided with the full capability to cast large objects at usable perfection? Perhaps flattening and forging and twisting was never used to combine smaller pieces of metal into larger ones until much later than casting?? I am sure that no attempt to forge gold together was attempted either, as I am sure that gold was never used as any form of tool, because before bronze-casting, gold was too soft, and would not make blades of any kind. Golden blades would not have been able to break obsidian, so they would have been useless. |
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Post by Timo Nieminen on Apr 5, 2020 21:46:27 GMT
So then, the years of surface mining that took place would not have depleted surface formations in any way, and even today I should be able to go to the copper mines and find naturally exposed native metals? Easily-available surface copper ore is mostly long-gone (surface deposits of easily-collected iron ore are still available (iron sand and bog iron), and still commercially exploited (iron sand)). This is separate from the question of ore quality. Native copper is largely exhausted (you might find some that erosion has uncovered). This is also separate from the question of ore quality - native metal is not ore. And the discovery of such metals probably coincided with the full capability to cast large objects at usable perfection? Perhaps flattening and forging and twisting was never used to combine smaller pieces of metal into larger ones until much later than casting?? Native copper was used to make things for millennia before copper smelting was discovered. Typically, the objects are small. Beads made from thin copper sheet are the most common pre-smelting copper objects found in Europe, but there are others, including a mace head from Can Hasan, one of the largest Old World native copper artifacts: www.tf.uni-kiel.de/matwis/amat/iss/kap_a/advanced/ta_1_2h.htmlIn theory, copper can be hammer welded either cold or hot. In practice, it oxidises very quickly, and the layer of oxidation prevents successful welding. Copper doesn't appear to have been successfully welded before copper smelting was developed, and after copper smelting, people knew how to cast copper, and small pieced were joined by melting them together and casting them as one object. There are rolled-sheet copper objects made from multiple pieces, rolled together. Fine for jewelry, but not useful for swords. I am sure that no attempt to forge gold together was attempted either, as I am sure that gold was never used as any form of tool, because before bronze-casting, gold was too soft, and would not make blades of any kind. Golden blades would not have been able to break obsidian, so they would have been useless. Gold was hammer welded long ago. Gold can be hammer welded cold. It doesn't oxidise, so doesn't suffer from the problems with copper. Gold tools have been found. Generally not cutting tools (except for ceremonial versions), but some were tools intended for use, such as tweezers. gold was too soft, and would not make blades of any kind. Golden blades would not have been able to break obsidian, so they would have been useless. Multiple gold blades have been found. These are usually described as "ceremonial". There are plenty of uses for blades other than breaking obsidian. While it is likely that the various ancient gold daggers were ceremonial, there are many other ancient blades for which the questions of whether they could or could not break obsidian was a non-issue for the makers. E.g., copper daggers. |
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