# Mixing gold with alloy 18k down to 9k



## weeedy (Mar 2, 2011)

Gday all, im new to this forum and new to collecting gold and i need a question answerd, my local jeweler will sell me the gold alloy for 9 to 14K at a nice price, and im wanting to melt down some 18K gold scrap that i have and turn it in to 9k , the jeweler tells me they have two diff gold alloys one to make 18k gold from fine 24k and one to make 9 to 14 K? would these both be the same product? can i use the 9-14K gold alloy to turn my 18k in to 9k or will it ruin the gold? as they jeweler doesnt want to sell it to me until im sure im getting the right alloy to mix .thanks for your help guys  

Cheers

Chris


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## nickvc (Mar 3, 2011)

Welcome to the forum.
This all depends on what type of alloy you want, do you want to make casting grain or sheet and wire, what colour do you want red, white or yellow?
You can make up alloys very cheaply as they are a mix of usually copper, zinc and silver with some silicon added if it's to be casting grain.


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## weeedy (Mar 6, 2011)

gday mate, im just wanting to melt down the 18ct scrap i have and convert it to 9ct staying the same color gold and il be pouring it in to a ingot mold


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## weeedy (Mar 6, 2011)

oh i also forgot to mention. i can buy the gold color alloys used for this here, but they sell two different sorts. one is more brittle or something along those lines? they dont want to sell me the wrong one and for me to ruin my gold?


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## nickvc (Mar 6, 2011)

Not too sure what exactly your doing or why but if your just wanting to melt a 9 k bar to keep just add exactly the same weight of copper, no need to spend money on alloys unless your going to work the bar, 9 k is basically a copper alloy with gold as the next largest contingent unless it's white gold in which case it's a silver or nickel alloy.
Hope this helps if not explain more fully what exactly you need from this bar.


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## goldenchild (Mar 6, 2011)

9k gold is 37.5% gold by weight period. You can use any other metal or combinations of to create what you want. 

There are thousands of sites on the subject. Here are a few.

http://en.wikipedia.org/wiki/Colored_gold

http://chemistry.about.com/od/jewelrychemistry/a/goldalloys.htm

http://www.timezone.com/library/archives/archives631703251272822958

Also. You cant make 9k into 14k without adding more gold.


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## goldsilverpro (Mar 6, 2011)

If I understand this right, the alloy(s) you would buy contains no gold. It is commercially available shot containing only the base metals and silver. The jeweler adds this to the correct amount of 24K to make up the karat he wants. Since you have no idea of the composition of either your 18K or of the alloying shot you would buy, I would think the results, when reducing your gold to 9K with one of these alloys, would not be predictable.


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## weeedy (Mar 7, 2011)

so realy im better keeping hte 18k scrap in a different batch then the 9k.. i might just first buy a 24k 1oz bullion and melt that down with the gold alloy to make 9k and then add the 9k scrap i have to the mix and cast it in to this mold i have wich is the map of australia and keep all the 18k seperate for another project


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## goldenchild (Mar 7, 2011)

Yes. Always best to start with pure metals when alloying. Trying to mix different karats or even the same karats can have ill effects like color change and pitting. If you learn to refine the 18k you can start with pure gold there too


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## Harold_V (Mar 7, 2011)

goldenchild said:


> Yes. Always best to start with pure metals when alloying. Trying to mix different karats or even the same karats can have ill effects like color change and pitting. If you learn to refine the 18k you can start with pure gold there too


I agree! My years of experience, working with manufacturing jewelers, convinced me that melting gold time and again is generally not a good idea. Each time it is melted some of the base metal oxidizes, eventually leading to poor quality gold, often filled with miniscule inclusions. It's not even a good idea to re-melt already made jewelry for re-use, although that doesn't prevent many from doing so. Those that do tend to experience problems that can be avoided. 

Harold


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