Melting Gold - blonde needs advise


Hello
I'm wanting some time to melt some small pieces of gold I have
accumulated into some form of nugget to wear... at the moment I have it
in panned form in small flakes from Idaho. I have my own kiln and can
produce a reduction atmosphere if needed but just wanted to get some
advise from a few folk so that I don't make a mess of it! Anyone fancy a
chat about this sort of thing?
regards
Heather in England
Reply to
Heather Coleman
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For jewlery we just melt it in a crucible using Oxy Propane or Oxy Acetlyene. No reducing atmosphere needed, then pickle the surface.
jk
Reply to
jk
Heather, Get a piece of wood charcoal ( Compressed Bricquets are my last choice ) and drill or carve an indention deep enough to keep the small flakes from blowing about. Use an Oxygen + Natural Gas , Oxygen + Propane , or even an Oxygen + Acetylene torch adjusted to a nuteral flame . If you do not have a Oxy - Gas torch, take it to someone and let them heat it. Heat with a flame large enough to melt but not so agressive as to blow out the small flakes . When molten dump the gold into water . This should form a freeform nugget . Continue remelting untill you like the form of the nugget . Pickle it in any acid water pickle or alum water pickle ( 10 % solution ) Solder a 22 K or 24 K jump ring for a chain and wear with pride. Use a easy or medium 18 K or 22 K solder . This Nugget is still native gold unless you add or remove anything .If You intend to sell it, check with the UK hallmarking authorities first.
Check Rec.Crafts.Jewelry on the Google groups or contact me off group . I can send resources easier via email, than I can over this group. ROBB.
Reply to
ROBB
No need for oxy/anything. A plain old propane plumber's torch will melt the gold just fine. Given the high gold content, I'd guess that pickling won't be needed either. It's likely to be mostly gold with a bit of silver and other metals mixed in, not likely to be much copper to oxidise on the surface.
The easiest way to melt this metal is certainly on a charcoal block but you should realise that you will not end up with a natural looking nugget. You'll end up with a blob unless you carve some shape into the charcoal block you melt it in. Even then, it won't a be a nugget. It's so easy to buy gold and so difficult to pan it out of a river. If I were you, I'd keep the flakes as a keepsake and buy some nice jewelry.
Reply to
bob mologna
I used to melt down everything from flour gold, to ring cut offs. A "Burno" crucible, as used in lost wax casting machines was used. These are inexpensive, and avoid contamination. A propane torch was sufficient, as a heat source.
Steve R.
Reply to
Udie
Never, use 22 karat or especially 24 karat for a jumpring. Both are much too soft, and will not last very ling. Use 18 karat.
Do not use easy or medium solder. Use hard solder.
Abrasha
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Reply to
Abrasha
Hear, hear!
Abrasha
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Reply to
Abrasha
What is flour gold?
Abrasha
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Reply to
Abrasha
Imported Idaho gold isn't subject to UK hallmarking authority. Once in hand in-country past customs, it's metal to be used however you might care to.
Reply to
Don Foreman
Seems like good info - but I have a question (open to anyone for an answer). I know gold is in different "qualities" i.e. 10K 14K 18K 24K, etc., and it's other metals introduced into the gold to change the "K" of the item, correct? Questions are: 1. When melted, do all the impurities (other metals) float to the top, sink, or what and how are they removed from the pure gold? 2. What is and how would you do "pickeling"? Thanks Ken.
Reply to
Ken Sterling
no
no
they (usually copper, silver and other metlas like zinc, and/or nickel or palladium for "white gold" )form an alloy with the gold.
Definition of alloy: a mixture containing two or more metallic elements or metallic and nonmetallic elements usually fused together or dissolving into each other when molten; "brass is an alloy of zinc and copper", "steel is an alloy of iron and carbon"
This is done in a process called "refining". It is a fairly complicated and exhaustive process, as well as very poisonous, because of the different chemicals used. But in a nutshell this is what takes place:
DISSOLUTION: Acids react with gold, silver, copper and other alloy constituents to form gold chloride solution, silver chloride precipitate and copper nitrate solution.
FILTERATION: Silver chloride precipitate and insoluble matter is seperated from solution containing dissolved gold and copper.
REDUCTION: Gold reagent, added to solution, reduces gold chloride to pure gold oxide precipitate.
WASHING: Gold oxide is removed from the remaining solution containing dissolved copper, is chemically washed and dried. You can now melt the gold powder and re-use as required.
In the jewelry workshop, pickling is the process that removes oxides from the gold alloy after it has been heated with an open flame for annealing or soldering. Typically a 10% warm sulphurioc acid solution is used for it. Or a more friendly compound (like SPAREX), which can be bought in granular form and added to warm water. That is what I use for safety reasons, and because it doesn't eat holes in my clothes.
WARNING!
If you contemplate making a sulphuric acid pickling solution, remember this: AAA, ALWAYS ADD ACID!!! I cannot write this bold enough or add enough exclamation marks. Never add water to acid, you'll regret it. If you're lucky you'll only lose your eyes!
It's better and a lot safer to use a solution like Sparex, you don't have to worry about acid explosions.
In goldsmithing school in Germany we were taught a rhyme to remember this:
Erst das Wasser, dann die Sauere. Sonst passiert das Ungeheure
First water, then acid Otherwise the "tremendously terrible" will happen
Abrasha
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Reply to
Abrasha
That mnemonic reminds me of a cautionary poem told by my science teacher when introducing us kids to sulfuric acid:
Poor little Billy isn't with us any more because what he thought was H-2-O was H-2-S-O-4
Abrasha wrote:
Reply to
Jordan
Gold dust so fine, it's like flour.
Greg H.
Reply to
Greg and April
You don't need any sayings or mnemonics for this.
The problem is simple, the dilution is exothermic. So you put the stuff with the largest thermal capacity there first, in the largest volume.
Thus any heat developed by the small droplets of acid as they enter the container of water is tempered by the large thermal mass of the water.
Doing it the other way causes local boiling and spattering. :(
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Reply to
jim rozen
This just proves that you DO need those sayings AND mnemonics, because your average goldsmith or person doesn't know about "exothermic" and/or "thermal capacity". They are not scientists or chemists.
The "people" that I was being trained with in goldsmithing school were high school aged teenagers.
Abrasha
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Reply to
Abrasha
Well. Nobody here anyway. The trouble with all the cute-sy poems is sometimes they get twisted around and you do the wrong thing.
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Reply to
jim rozen
Hello again :-) Thanks everyone for your various advise and comments...
Is there a main dealer of gold for using in jewellery who I can rely on to supply me here in the UK should I go down that road instead of trying to melt panned material. I'm still in two minds about melting material or just getting something to play around with (typical fussy artist I know... giggle). Obviously I can't afford to be ripped off. I work with pottery but always fancied melting some gold... hence my original question on this group. I'm thinking there are probably lots of rip-off merchants in the gold business, and especially on e-bay. Last thing I want to do is buy one of those hallmarked sealed ingots only to find it's a something that's really not worth the gold it's made of or has some fake hallmark on it. Originally I bought my flakes from a main e-bay seller "smoothstonesprospecting" in Idaho who appears to be reputible, it's nice looking material with a rich colour and good weight, some small visible impurites include bits of quartz, to be expected though. As far as having a little hoard of flakes I'm very pleased with it but it's working out cheaper to buy small flakes/dust than a single larger nugget. They told me that some of their buyers melt it and then quench in water and bash it to remove the crust of waste material but they don't appear to do much or any melting themselves so I did not get much advise from them... they just pan it. Maybe I should just write to some of their big bidders until I find someone who has used this material. There's one dealer in the UK here I know of... "Exchange Findings" I might have to contact them as they supply official material for goldsmith's etc. I have to admit I am clueless really! Is it better to buy gold from the USA. Another option I guess would be to try using some of that "precious metal clay" that you can fire in a kiln but maybe that's cheating :-) My original idea was to make myself a nice piece of good quality jewellery to wear... I rarely buy custom made material because I think it's more special to make it myself.
OK, enough for now.. just chatting. regards to all Heather
Reply to
Heather Coleman
Nothing cutesy about it. It has saved lives! Abrasha
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Reply to
Abrasha
I dunno.... I kinda like the AAA always add acid.... Simple to remember and pretty tough to screwup I mean it's not always add WATER because that'd be AAW, which is what you would be saying if you did it wrong. Ken.
Reply to
Ken Sterling
would just melt an old ring or two in the ladle, the skim off the copper, zinc, etc., and then you would be left with pure gold to play with... Figures - nothing can be simple. Thanks for all the info - that was great. Ken.
Reply to
Ken Sterling

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