My gold will not melt, not hot enough?

xelexo
Shop deals on ebay
shop deals on amazon
Advertise with us
Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
T

Thill824

Member
Joined
Aug 24, 2021
Messages
11
So I’ve got about 25 grams of gold which I dropped out of solution using sodium metabisulfite. Process seemed to work pretty well I was left with brown sediment and clear solution. I drained and rinsed. Put some borax in a preheated graphite mold and torched with propane until it started to melt, then I added the gold and torched it for upwards of 10 minutes. No melting though.
 
Chances are the heat is escaping faster than you're putting it in. A candle actually produces a high enough temperature to melt gold, but it doesn't provide very much of that temperature. As soon as you get a couple of millimeters away from the hottest part of the flame, it gets too cool. A graphite mold will conduct heat away from itself very well, so you're not putting enough heat in to get the gold molten.

Imagine trying to water your lawn on a hot day. If you try with a tiny hose with a drinking straw on the end of the hose, the water will dry up almost as fast as you try to put it on. Your lawn will die. But if you use a larger hose and let it flow through a larger opening, like a large lawn sprinkler, you'll wet and saturate the ground and your lawn will survive.

It's the same when you try to melt gold. You have to put heat into the system faster than it's escaping to get it hot enough to melt the gold. I'm guessing that the heat is escaping faster than you're putting it in.

Try a melting dish that's well insulated and you should enjoy success.

Dave
 
As Dave has pointed out you simply need to insulate your dish to allow the heat to be retained and so melt your gold, even a small torch can melt gold so long as you insulate the dish.
 
Thanks for all of the replies, I had a feeling the setup lacked insulation and the ability to retain any of the heat, I will get a ceramic dish and some insulation and try this again.
 
So I got a proper 50ml ceramic crucible and some fiber frax insulation and gave it another go. No luck. Anybody want to give it a go and keep a couple grams as payment?
 
Not sure if you have a budget but well worth the 2 grams you'd be giving someone else to melt your gold. I used to use these all the time and they are $70 at Lowes. This will melt it, and relatively fast.

https://www.lowes.com/pd/BernzOmatic-Cutting-Welding-and-Brazing-Torch-Kit/50126405

Andrew
 
Is there any place I could sell it as is? I think I have 25-30 grams of high purity gold, or offers on here??
 
Out of sheer curiosity, may I ask why are you using Borax after precipitating Gold from a, what I assume is Aqua Regia, solution? The precipitate is pure Gold, no?
 
I would only use borax to glaze the dish, I’ve had this problem to. First problem was not well enough insulated. Then too much borax in the dish… even once melted seems to act like a heat sink, and the gold would never fully melt until I dumped out the excess melted borax. I had an old post on here about this and Goran sent a photo that really helped. I’ll try to find it
 
You may need a larger torch, I use a large oxygen propane cutting torch.
It still even has the Oxygen by-pass, so the only thing you have to be careful of is not hitting that while you are trying to melt the metal in a dish.
The spray is quite spectacular if you do.
 
Thill824 said:
So I’ve got about 25 grams of gold which I dropped out of solution using sodium metabisulfite. Process seemed to work pretty well I was left with brown sediment and clear solution. I drained and rinsed. Put some borax in a preheated graphite mold and torched with propane until it started to melt, then I added the gold and torched it for upwards of 10 minutes. No melting though.
Click to expand...
Well there is your first problem.... NEVER put borax in a garaphite crucible. In case you didn't know, graphite is pure carbon. Most upscale crucible makers impregnate and glaze the graphite crucibles for one purpose... to create a barrier between the carbon and the oxygen. By adding borax, you are basically turning the graphite (carbon) into a charcoal briquette.
 
You can try a refractory crucible and adding borax in a ratio of 10 percent to gold, adding in small amounts and lowering the temperature between each addition, because it can produce dangerous projections. In addition, 25 grams of gold together is not melted by any conventional propane torch. Good luck..!
 

Latest posts

Back
Top