Bronze is used in a wide range of applications. However, like any other metal, there are genuine bronze and fake bronze. When you are a newbie in the metals industry, you might encounter metal dealers that sell fake bronze. If you want your project to have the best quality, you have to be able to distinguish if the bronze is authentic or not.
A bronze piece can easily be determined if it is real or not by the way it sounds when hit by an object. For example, a wooden dowel. Strike the bronze piece with it and the piece should emit a ringing sound instead of a thud. This ringing sound lasts for a couple of seconds, then fades. On the other hand, fake bronze or bonded bronze (a mixture of bronze powder and resin) will create a dull, heavy sound. The perfect placement of tin molecules within the copper molecules acts like a wall that allows reverberation of sound instead of absorbing it.
Pure bronze is heavy, like most metals. If a bronze piece is small, you may try to carry it. You have to feel that pull and weight upon carrying the piece. The mixture of resin and bronze powder is significantly lighter.
Color and Patina
The color of bronze varies, depending on the amount of copper and tin. It has a wide variation of color because its contents have a lot of variation as well. Bronze that has more tin content usually has a lighter shade, while if it has more copper, it has a darker shade. The shine that bronze has is also easy to tarnish. This happens before patination. The patina will form on the surface as a result of the copper content. Bronze that stays shiny for a long time is fake.
One of the unique characteristics of bronze is its malleability. It is commonly used in making sculptures. Bronze expands from a small amount when transforming from liquid into solid. This is desirable when pouring bronze into a mold. It fills the holes of the mold and when chiseled, it does not easily crack. If you want to know if a bronze piece is real, you can chisel a small part of it with a small amount of force and it will not crack. If it does, then the bronze piece must be made of resin, since it is significantly softer than bronze.
Iron as Bronze
Other than resin and bronze powder combination, other artists and manufacturers also use iron as an alternative. It is cheaper than bronze but stronger and harder than resin. Most of the time, it can pass of as bronze. One of the easiest ways to determine if it is bronze is sticking a magnet to it. Bronze is non-magnetic while iron is highly magnetic.
It is important to inspect bronze pieces and parts. Sculptures are commonly duplicated using fake bronze. Mechanical parts are critical, as the bronze’s authenticity can affect the performance of the equipment.
Learn more about bronze parts and manufacturing at Diversified Bronze & Manufacturing Inc.