New Zealand Gold Prospecting & Metal Detecting Forums Archive

The forum has moved to community.paydirt.co.nz, see you there!

This forum is now an archive to preserve the knowledge and finds posted here.

melting some gold - crucible?

1864hatter		Posted : Thursday, 21 February 2013 3:43:48 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 4/08/2010(UTC) Posts: 1,007 Location: Auckland.... Thanks: 49 times Was thanked: 566 time(s) in 269 post(s)		Hey guys, any ideas about what I can use to melt gold in. I have access to an acetylene torch and would like to melt some fines into a button. Also any useful info about flux etc to use would be sweet. Cheers
		And now....On sandy beaches and muddy soil, rings and coins await my coil!

oroplata		Posted : Thursday, 21 February 2013 4:15:05 PM(UTC)
Rank: Gold Ingot Groups: Registered, Moderators Joined: 16/06/2011(UTC) Posts: 1,040 Location: Christchurch Thanks: 23 times Was thanked: 211 time(s) in 152 post(s)		http://goldrefiningforum.com/ will have all the information you need. Highly recommended.
		WWW

NUGGY		Posted : Thursday, 21 February 2013 5:13:13 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 20/07/2012(UTC) Posts: 267 Location: greymouth Thanks: 85 times Was thanked: 76 time(s) in 58 post(s)		Hi Hatter, I have used a fire brick (they are paler than ordinary bricks) with a depression made with an angle grinder in one side. Had a piece of cast iron with a depression in it that was good too. Don't use any bright machined steel or stainless steel as your gold may stick to it so hard it will be a major to get it off again. If your gold melt button looks dirty and discoloured sprinkle some borax around it and re-melt. the borax sucks out the crap somehow, then hardens to a glass like substance that is easy to break off. NUGGY

oroplata		Posted : Thursday, 21 February 2013 5:24:30 PM(UTC)
Rank: Gold Ingot Groups: Registered, Moderators Joined: 16/06/2011(UTC) Posts: 1,040 Location: Christchurch Thanks: 23 times Was thanked: 211 time(s) in 152 post(s)		You can make a mould for pouring your gold into using 3 pieces of angle iron - the centre piece in a V with the other two welded at each end as legs. Before pouring the molten gold into it, you coat it with carbon by using the torch burning acetylene only. A good source for borax is "Bin Inn" - look in the cleaning products dept. Be very careful with flour gold - if you put your torch directly to it you may blow all the gold out of the depression!. Heat around the edge of it with a circular torch motion and wait for the bits at the edge to melt, then slowly bring the torch into the centre. In other words, heat the brick to the sides of the gold first, beforehand.
		WWW

treeman		Posted : Thursday, 21 February 2013 7:03:25 PM(UTC)
Rank: Gold Nugget Groups: Registered Joined: 1/02/2012(UTC) Posts: 32 Location: Arrowtown, Thanks: 10 times Was thanked: 16 time(s) in 11 post(s)		Just at this very moment powered up my new microwave kiln. finally got all the parts i need. been 40 minutes and did a stir at 30 minutes. just getting mold out of oven where its preheating, her in doors not happy about that. Haha looking good. so back to car port and see what pours. tell result in an hour or two cheers treeman

gogold		Posted : Thursday, 21 February 2013 7:28:50 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 5/01/2012(UTC) Posts: 217 Location: gore Thanks: 4 times Was thanked: 56 time(s) in 45 post(s)		just use a bit of borax, put a bit on before you start it helps stop the fines form blowing away also keep the torch away a bit if its really fine at least till it starts going redish then you can give it shit with the acetylene and it shouldnt blow away. can just use a half potato with a scoop taken out with a spoon, just put gold/borax in the scooped out bit and aply heat. let it cool for a few seconds and tipinto water, if it still has a few bit of black sand etc just repeat it. can also get graphite molds of ebay fairly cheap only take a few days to get here. or you could get a block and carve it out youself.

oroplata		Posted : Thursday, 21 February 2013 7:49:22 PM(UTC)
Rank: Gold Ingot Groups: Registered, Moderators Joined: 16/06/2011(UTC) Posts: 1,040 Location: Christchurch Thanks: 23 times Was thanked: 211 time(s) in 152 post(s)		Originally Posted by: treeman Just at this very moment powered up my new microwave kiln. finally got all the parts i need. been 40 minutes and did a stir at 30 minutes. just getting mold out of oven where its preheating, her in doors not happy about that. Haha looking good. so back to car port and see what pours. tell result in an hour or two Excellent! Let's see a piccie of the finished product :)
		WWW

treeman		Posted : Thursday, 21 February 2013 7:59:26 PM(UTC)
Rank: Gold Nugget Groups: Registered Joined: 1/02/2012(UTC) Posts: 32 Location: Arrowtown, Thanks: 10 times Was thanked: 16 time(s) in 11 post(s)		well that was a learning curve, I did not let it get hot enough and the glass poured of and left a button in the crucible. so back in and gave it another 20, now this time it was that hot I spilt it so not a good look on the first go. I don't think i have a steady enough hands for this.haha but its all out there cooling now and i am having my cold tea. it does work can't wait till the weekend and try with some more concentrates PIC well no not on the first gooooo. cheers Treeman

kiwijw		Posted : Thursday, 21 February 2013 8:03:20 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 28/03/2010(UTC) Posts: 1,152 Thanks: 92 times Was thanked: 658 time(s) in 324 post(s)		G'day hatter, A potato. Check this out. http://www.goldcitydetec...g.com.au/meltinggold.php Good luck out there JW :)

tillerman01		Posted : Thursday, 14 March 2013 5:23:41 AM(UTC)
Rank: Gold Flake Groups: Registered Joined: 3/07/2012(UTC) Posts: 14 Location: Arkles Bay, NZ Thanks: 90 times Was thanked: 1 time(s) in 1 post(s)		Great explanation and photos of the process JW, thanks. I never would have believed a potato could work! My son and I used the borax process in a crucible I got off Ebay for our fines and got a nice button weighing 11.6 grams but it's still quite dirty looking, I haven't got around to re-cooking it yet. Cheers, John

1864hatter		Posted : Thursday, 14 March 2013 8:13:12 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 4/08/2010(UTC) Posts: 1,007 Location: Auckland.... Thanks: 49 times Was thanked: 566 time(s) in 269 post(s)		hey guys cheers for all the info, I think I will give the potato method a try. Want to wait till I have a half Oz of fines tho. I'll post pics when I finally do it. May be a month away yet as I dont get that much fines.
		And now....On sandy beaches and muddy soil, rings and coins await my coil!

gogold		Posted : Thursday, 14 March 2013 9:52:40 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 5/01/2012(UTC) Posts: 217 Location: gore Thanks: 4 times Was thanked: 56 time(s) in 45 post(s)		Originally Posted by: tillerman01 Great explanation and photos of the process JW, thanks. I never would have believed a potato could work! My son and I used the borax process in a crucible I got off Ebay for our fines and got a nice button weighing 11.6 grams but it's still quite dirty looking, I haven't got around to re-cooking it yet. Cheers, John redo it with a bit of borax, if its still dirty then get some nitric acid off trademe and soak it in that cleans it up bloody good just gotta rinse it aftawards and be sure to nuetralize the acid with some baking soda.