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Author Topic: gold coin id  (Read 13202 times)
Chef Geoff
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« Reply #15 on: May 08, 2011, 09:32:09 AM »

Gold is relatively soft and so should bend back quite easily, when straightening any coins I tend to use a wooden pencil in the same manner as you would use a rolling pin. Good luck
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mooster
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« Reply #16 on: May 08, 2011, 09:45:42 AM »

thanks for that geoff. ill give it a go.
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tyna
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« Reply #17 on: May 08, 2011, 11:09:13 AM »

Gold is gold - straight, bent, whatever, it's always nice to find.  Well done mooster and good for you   Cool
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WeLsH Boi
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« Reply #18 on: May 08, 2011, 02:38:53 PM »

Nice coin m8. Try warming it up in a pan of water it makes the metal a bit more malleable. I done the same with a Mary groat. Warmed it up for a couple of mins in a pan of boiling water, placed it in between 2 plastic chopping boards and gentely tapped it flat. Worked a treat.
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Chef Geoff
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« Reply #19 on: May 08, 2011, 02:59:25 PM »

your only fooling yourself lol. water can only get to 100* and will have no effect on gold or silver in any way. for silver you need to anneal it which will mean getting the coin to at least 600* (and preferably 900*) to have any worthwhile effect.
Please DO NOT rely on hot water it's only cleaning your object and nothing else.
« Last Edit: May 08, 2011, 03:57:11 PM by Chef Geoff » Logged
nfl
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« Reply #20 on: May 08, 2011, 03:54:26 PM »

i dont know,i had a gold sov that was bent,chucked it in a pan of boiling water for 20 mins took it out placed it between 2 blocks of wood then repetadly smacked the wood with a hammer Roll Eyes........ Grin Grin Grin..it took the bend out Wink
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WeLsH Boi
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« Reply #21 on: May 09, 2011, 07:54:43 AM »

Granted your not going to hit smelting temps. But the hot water defiantly makes a difference in the straightening process. From my limited  experiences any way.
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Chef Geoff
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« Reply #22 on: May 09, 2011, 08:17:21 AM »

Smelting temperature is 1600* and you have no worries of reaching that, but what you are trying to do is anneal. This is not making the metal soft in fact as soon as you have heated the metal you cool it and work on it cold. When a coin is first made the crystalline structure is all laid down in a regular form due to the heat, when it is then bent the structure is stretched out of shape and gaps appear at a microscopic level, which makes the structure very brittle and this is what causes some items to snap when being straightened.
Annealing is a process of heating and thus realigning the crystals so that as you begin to straighten the coin each bend is the first.
Depending on the severity of the bend, the coin may need heating several times before it is straight.
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tyna
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« Reply #23 on: May 09, 2011, 03:40:27 PM »

So you all - put that in your pipe and smoke it  Shocked Grin Grin
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The Doc
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« Reply #24 on: May 09, 2011, 05:40:50 PM »

Smelting temperature is 1600* and you have no worries of reaching that, but what you are trying to do is anneal. This is not making the metal soft in fact as soon as you have heated the metal you cool it and work on it cold. When a coin is first made the crystalline structure is all laid down in a regular form due to the heat, when it is then bent the structure is stretched out of shape and gaps appear at a microscopic level, which makes the structure very brittle and this is what causes some items to snap when being straightened.
Annealing is a process of heating and thus realigning the crystals so that as you begin to straighten the coin each bend is the first.
Depending on the severity of the bend, the coin may need heating several times before it is straight.


I totally agree Geoff. Any coin that will straighten after being boiled in water would have done just as well cold. Annealing is the only reliable way to go.

I'm not sure if I would have been brave enough to do it, but watch this as an example of superlative work, with Gordon straightening an Offa penny:

http://www.mlotv.com/view/204/offa-saxon-coin/
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WeLsH Boi
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« Reply #25 on: May 09, 2011, 07:56:44 PM »

Just read an interesting article on annealing here. Though I tried the water method after being instructed to at the fosse way rally on a bent hammered. My first hammered actually it seemed to work. So I take it that it would of straightened just as well cold? As I have a lizzie hammered that's a little bent and wouldn't mind flattening it.


http://www.ukdetectornet.co.uk/index.php?option=com_content&view=article&id=75%3Astraighten-a-hammered-coin&Itemid=60
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