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Anyone done any smelting?
roman holiday  
Posted : Saturday, 8 May 2010 10:33:53 AM(UTC)
roman holiday

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Hi guys, I've just been wondering what to do with all my allevial gold flakes once I've found it. :)

Has anyone tried a bit of smelting in a crucible using a blow torch? I hear it takes something like 1000 degrees to melt the gold and see impurities burn off. Of course this wouldn't get gold near to the .999 purity needed for bullion, but would seem a fun exercise nevertheless. I remember my older brothers having fun turning turning lead headed nails into sinkers when I was a kid. :)
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gavin  
Posted : Saturday, 8 May 2010 4:58:14 PM(UTC)
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Have a chat to a friendly jewellery maker down any local market - often they'll be able to give good tips on smelting. Had a chat with one here in Christchurch at the local arts centre - seemed very willing to pass on his knowledge. Unfortunately I promptly forgot most of what he told me as I didn't apply is straight away.

I do seem to remember that he said you could get some sort of pumice stone you can carve your shape in to to get the shape you want your gold in after cools down. Also mentioned something about some chemical you can add to prevent molten metal spitting / sticking / something(?) and also heating up the receptacle you're pouring in to so molten gold doesn't spit when it's poured in to it.
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roman holiday  
Posted : Saturday, 8 May 2010 7:25:38 PM(UTC)
roman holiday

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Cheers Gavin, yeah, I'm sure there are ways to do it... back yard furnace sort of thing. Wouldn't it be cool to hammer out into fine leaf half an ounce or so and gild some object of your choice. I've heard gold is so ductile just a bit can stretch for miles. Or would that be attracting unwanted attention. :)
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gavin  
Posted : Monday, 10 May 2010 2:39:10 AM(UTC)
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Wouldn't mind making a little ingot out of the flakes once I have enough, but figure the nuggets look pretty cool as they are :)
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criticol  
Posted : Tuesday, 18 May 2010 11:18:22 AM(UTC)
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Hello Roman H,
You may find the following link of assisisance.

http://www.artmetal.com/...proces/cast/ag_cast.html

Cheers--- Colin.
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criticol  
Posted : Tuesday, 18 May 2010 5:48:56 PM(UTC)
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Again Roman H.
I forgot to tell you that if you have problems (or expense wise ones)getting hold of refractory (fire proof)materials for a furnace lining, give a thought to ordinary house wallboard lining (the plaster filled type) as this plaster will withstand "1400" degrees of heat, amply enough scope for melting gold,(Minimum= "1060", maximum="1200")
To utilize this cheap resource, soak wallboard in water till paper covering gets soft enough to peel off the plaster, let plaster dry and crush to a powder. You then mix this plaster with a bit of cement and mould it to whatever shape you desire,and let it dry out completely.But it has to have support around it, or it will collapse with time,(a large outer tin can or similar is enough to support it with, and you can insert a smaller diameter tin can inside this, leaving a space of say 100 mills between them and fill this with your mixture,leaving untill set.You can also make your base first,setting the cans on this and then filing them when the base is still slightly unset so as to mould them all together in one go.

Cheers---Colin.
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roman holiday  
Posted : Wednesday, 19 May 2010 6:18:05 PM(UTC)
roman holiday

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Hi Criticol,

thanks for the info.... I am definitely interested in doing something like this for fun one day... first will have to find the nuggets but..:]

I have been thinking about sluicing and crevicing when I start out... but have to admit I've now got an interest in detecting after the account you gave on the Lyell creek area.... I like the idea of doing both, adding some diversity to your toils, though no doubt I'll focus on the one that leads to more success.

I am stuck in a concrete jungle at the moment [Seoul} and looking forward to beginning my fossicking adventure, and the wide open spaces on the west coast, in the coming year.

Regards.
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