Gold is one of the most versatile and useful minerals known to man. From sconces and sculptures inside the palaces of kings to the wedding rings and family heirlooms of the average Joe, gold has seen more everyday use as new smithing techniques have been born.
Far from being an exclusive material for the rich and famous, today, you can find gold in airplane control systems, computers, and smartphones. Do-it-yourself goldsmithing has also become a niche hobby worldwide—not that it has ever fallen out of favor in the past thousand years. So, people looking into the hobby and anyone who wants to invest in gold are curious: What is the melting point of this exceptional metal?
For a straight answer, the melting point of gold is 1,948 degrees Fahrenheit or 1,064 degrees Celsius. That’s hot enough to burn through car engines, the Earth’s crust, and many other metals. But how do you achieve the melting point of gold if you’re looking to make a brand-new ring, bar, or coin?
How to Melt Your Gold
Defining a Few Terms
Before going through the arduous task of building a furnace of your own, you need to know the definitions of some technical terms you might encounter when researching how to melt gold. The five most common ones you’ll find on the internet are smithing, forging, karats, oxidation, and ductility.
Smithing and forging are synonyms that both mean using heat to fashion a weapon, accessory, or medium of currency from a metal. A goldsmith is a person who makes gold products exclusively, while a blacksmith is a general term for someone who also works with iron, brass, and other assorted ores. A forge is a facility where smiths work on their projects in the same way a mechanic works in a garage.
Karats refer to the purity of a gold item. A 24-karat gold product means it contains gold and nothing else. Pure gold accessories are impractical to wear because they bend easily, which is why you’ll find 10-karat, 14-karat, and 18-karat gold rings but seldom any 24-karat variants.
Oxidation is the rate at which gold tarnishes, which is how quickly it will turn black after constant use or a long time in storage. 24-karat gold never loses its shine, but most gold items include copper and alloys, which will absorb oxygen particles after some time and then turn black. You can clean your gold items that have seen oxidation with a baking soda and salt solution easily made at home.
Finally, ductility means how far you can stretch gold without it breaking. This quality of gold is one of its most important selling points as people can make leaves, sheets, and microchip parts that are extremely thin, light, and highly conductive. Its unparalleled ductility even makes it a popular addition to luxury desserts like ice creams and cakes in places like Abu Dhabi and New York.
How to Build a Furnace
The furnace is the heart of every forge. Without it, you won’t a high-enough source of heat to melt your gold and shape it into something useful. Thankfully, you won’t need thousands of dollars of equipment to make a furnace that will burn hot enough for you to begin smithing.
First, determine how much gold you intend to melt. The size of the furnace will depend on the demands of the job. If you’re making a sconce or a picture frame, you’re going to need a larger furnace than when you’re making a knife or a couple of chalices.
You can make a furnace out of a tin can if you’re making a ring or a large trash can if you’re making a trophy.
Once you’ve found a cylinder of the right size, create a little hole along its side so you can insert a metal pipe. Your furnace will need a lot of charcoal, so solder a mesh grate about hallway through your furnace. Now dig around your can and create a hole that’s twice as big, and finally place clay and firebrick to intensify the heat.
Use some duct tape on the open end of your metal pipe and place a hairdryer to blow through it. Once your furnace is burning hot, it’s time to start the purification process.
How You’ll Cut the Fat from Your Gold
Most gold items you’ll find in the market are zinc, copper, and nickel alloys because these minerals allow gold to keep its shape. Thankfully, none of them bond with oxygen at the same temperature as your precious metal. Using a mixture of sulfuric acid, sodium nitrate, and silica, you can watch the zinc, lead, copper, and nickel parts surface at the top and the sides of your boiling gold, making it easy for you to slough them off.
Once you’ve cut the fat from your gold, be ready to pour what remains into a casting dish. Despite its medieval name, a casting dish has nothing to do with spells or witchcraft, but merely a cast iron dish you can use to create bars, coins, and symbols if you’re not going to create a unique design with the delft casting method.
Melting Your Gold
Place your gold ore into the crucible and start heating the furnace by setting alight the charcoal surrounding it. As the charcoal turns orange, put your crucible directly on top and add some more until it’s full up to the sides. Turn your hairdryer on so your coals burn with more steady heat.
You’re going to need a lot of air and charcoal to reach your nearly 2000-degree Fahrenheit target, so if you’ve been putting in more coal, but the temperature isn’t rising, turn your hairdryer up to a higher setting. However, be careful to stop once you’ve gotten to the boiling point as overly high temperatures might cause your gold to bubble and liquefy to the consistency of cream, damaging its natural form or cause your crucible to explode.
After a while, your gold will start to swirl in its crucible. That is your cue to blend it with your oxidizing agents.
The copper, zinc, nickel, and lead in your gold will bubble to the top. Pick up your crucible with your boiling gold inside and then pour the slag into a second crucible.
Once your gold begins to cool, or even if it’s just a couple of hundred degrees under its boiling point, it will become too dense to pour. You can use sodium tetraborate or borax as a liquid thinner, which will bring up the hardened silica to your gold’s outer surface as it cools.
A Smooth Finish
Before your gold begins to cool, take it out of the furnace and pour it into your casting dish. A casting dish with no bends or creases will give you a flat plate or coin shape, perfect for inscription if you want to make it truly yours. If you’d like to turn your gold into another more complex shape, you’ll need to look into gold casting, which is another art form in itself.
Why Melt Your Gold?
Since time immemorial, people have been melting gold and turning it into spearheads, sundials, and false teeth. Gold has highly conductive properties, and many stereo manufacturers use it for wires, speaker components, and even phonograph records. The famous phonograph aboard the Voyager I, which communicates what it means to be human to whatever extraterrestrial lifeform it comes across, was made of solid gold.
Even though you can deform pure gold with an instrument as simple as a ball-peen hammer, it will become nearly indestructible when you alloy it with copper or zinc. The only way you can shape it and combine it with other metals is to melt it. It’s also the only way to create inscriptions on it, which is a requirement if you plan to sell your gold in the future.
Does Purity Affect Gold’s Melting Temperature?
The lower the karat rating of a gold item, the less gold it contains. The more metals that dilute it, the more it will change properties. Thankfully, gold’s melting point doesn’t change no matter how many other metals you throw in the mix.
However, gold’s color, ductility, and hardness will vary depending on its alloy. Zinc and copper are much less ductile than gold, so if you’re planning to make gold leaves or other sheet-like ornaments, you’re better off with a 24-karat rock.
Visit Oxford Gold Group to Learn More About Melting Gold
At Oxford Gold Group, we’re not just obsessed with turning a profit from our precious metal investments. We also like to see what they can do for us when we hold them in our hands.
We’re your experts in gold, silver, platinum, and palladium, and we help thousands of people every day save up for retirement by investing in these metals.
Gold has been valuable even before humans thought up the concept of an economy. Get yourself a hedge against inflation and diversify your portfolio by investing in precious metals today. Call us at 833-600-4653 to learn more about melting gold and making money from it.