Experienced jewelers and fabricators know that typical “cold brazing” is more accurately described as “resistance brazing.” Cold welding tools like the popular ColdHeat welding pen have a slotted tip that allows electric current to flow through each point. When the ends come in contact with the solder, the probes and solder heat up quickly due to their resistance to the current flowing through them. Pulling the tips away from the solder breaks the circuit, and everything cools down quickly.
What if you could use a similar technique on any metal, including those with very high melting points like gold? Materials scientists at Iowa State University may have revolutionized the manufacturing industry by developing a welding method that does not require heat or electricity. It forms a shell around microscopic droplets of metal and keeps them fluid, even if their surroundings are below their melting temperature, until the shell explodes and the metal sinks and solidifies like a weld.
First of all, we will note the difference between welding silver and gold jewelry. One of the most critical differentiators is temperature. Gold and silver solders have different temperatures. Silver comes in four different versions: light (E), soft (S), medium (M), and problematic (H), each with a different starting temperature. On the other hand, gold can be found in many other forms. You should consider the 8 to 22 carats and the color: white gold, yellow gold, and rose gold. Here is a breakdown of the melting points for welding gold jewelry:
Low, easy – 650-720 ° C
High carat, light: 700-715 ° C
Weak, hard – 755-795 ° C
High, hard – 790-830 ° C
Cemented carbides have a crystalline structure, so the molten metal is subjected to the physics of supercooling. The ISU researchers created the droplets mentioned above by turning the molten metal into foam, allowing it to cool gradually. Oxygen in the foam causes the droplets’ outermost surfaces to form a thin layer of metal oxide. This oxide reacts with acetic acid to create a smooth oxide-acetate layer, which allows the core to remain liquid as it cools. This ultra-thin layer prevents the liquid metal from coming into contact with the nucleation centers necessary for solidification. The liquid immediately flows out and solidifies by cracking the shells, bringing the surfaces together, something like a water ball filled with superglue. During the demonstration, the researchers used this technique to solder a gold wire to gold foil, punch holes in the silver foil, and hold the aluminum foils together.
Solder like gold jewelry
Let’s dive into our step-by-step guide on how to solder gold jewelry.
Refine the gold. This is the first step in learning how to solder gold and gold jewelry. This allows the metal to bond suitably. Simply dip the jewelry into the etching solution using tweezers. Then rinse with water to remove the acid.
Secure the workpiece with a clamp or paper clip. Place the piece of jewelry you are working on on the solder block and secure it with a clamp or paper clip. Make sure the gold coins fit perfectly. Otherwise, the weld may fail if the gap is too large.
Add solder flux to the gold. It should only be applied to areas of the weld to be joined to ensure that all contaminants are removed, and surface discoloration is avoided.
Heat the flux. Take a flashlight and gently heat the stream until the water boils. Strong protectors remain on the part.
Apply gold and heat. Add a small piece of gold solder to the joint and heat the surrounding metal with a hand torch. < healthy> Good advice! </ strong> Slowly move the flame back and forth to heat the joint along its entire length. Once the solder begins to melt and extend along the seam, stop, and you should see the sides come together.
Cool the product and the process. Once the piece has cooled, place it in a double boiler. Then, using copper tongs, gently dip the piece into the marinade bath and let it sit until the scale is removed from the surface.
Finish your job. Once the item is removed from the stripping solution, rinse it in a water bath and check for discoloration. If necessary, simply wipe away stubborn scales, and voila!