The Chemistry of Patina in Chemicals

A wide assortment of chemicals, both industrial and household, can provide a wide spectrum of beautiful patina effects. Many artists use them as decorative surface embellishments both for texture, color, or both. There are also a number of paints that when properly applied will impart a certain “oil paint” appearance to the surface it is on. These types of materials are usually called “patina” chemicals. Some common types of these chemicals include lampworking pigments, alkyds, alkes, and varnishes. Each type of chemical has its own advantages and disadvantages for use in different painting techniques.

Copper is one of the most well-known metals used in creating patina chemicals. This metal is soft, ductile, and extremely malleable making it ideal for chemical forming. It was probably discovered by accident when explorers found copper nuggets embedded in the ice off the shores of Canada. Copper has many desirable properties and is very effective for many art applications. Copper can be formed into rings, necklaces, bracelets, and even knives.

Iron is another metal commonly used in patina creations. Like copper, it can be formed into all kinds of attractive patterns. Like copper, it can be formed into a hard polish, soft polish, brushed chrome, and a variety of other finishes depending on how it will be used. For this reason, iron is often seen combined with other metals in combining patina effects. Examples of combination metals include aluminum oxide (sometimes called “black steel”), phosphorous (an inert dye), and boron.

Aluminum oxide is a popular choice for many people because it provides a non-reflective surface that makes it great for applying to flat surfaces. But if the flat surface is too small (or simply too dark) for aluminum oxide, the best choice is to use zinc white. Zinc white can be applied to nearly any flat surface and provides a high gloss and mirror-like appearance. However, the most attractive combination of chemicals for a patina are those that create a surface with both a low gloss and the reflective property of gold. This technique is called chemical patina.

Other common combination patinas are those that create a gold-like appearance on metals with a silver-like appearance. Commonly these are called golden patina and silver patina. In these cases, the silver or golden patina is often deliberately allowed to darken before it is coated with the gold. The coating can be nearly invisible once it has been applied. Commonly these patina coatings are applied to old metals to give them an aged, rusty appearance. These can be deliberately done with alloys as well as with copper, iron, aluminum, brass, and other metals.

Other combination patinas can be created using chemicals such as ferric oxide, which turns metal into a blacksmith’s forge. Ammonia and aluminum oxide provide a bright metallic luster when mixed together in mixtures that are applied to flat surfaces. The resulting patina is attractive and durable and can also provide some amount of insulation from the metal surface.

A third commonly used combination patina is created using the results of other chemicals. Commonly these are referred to as varnishes, and they provide an attractive, protective, non-porous coating that is easy to clean. They can be applied to metals and plastics as well as to leather. The chemicals involved often contain ammonia, although the products can also contain other chemicals such as tannic acid.

Chemical-patina combinations offer a multitude of advantages. These patinas are attractive, durable, and even cost effective. Additionally, they can be applied to a wide variety of surfaces and offer the advantage that they offer a self-leveling protection against erosion, cracking, and bonding with other materials. However, if the chemicals in your project have an alcohol content greater than 40%, you should pay special attention to the compatibility of the chemicals with your intended surface. This can be especially important if your intended surface is made out of copper alloys.

City Chemical is a producer of chemicals and some of them are: 1,4-Naphthoquinone, 130-15-4, Triolein, 122-32-7, Antimony Trioxide, 1309-64-4, Silver Nitrate, 7761-88-8, Aluminum Fluoride, 7784-18-1, Ammonium Iodide, 12027-06-4, Cupric Oxide, 1317-38-0, Humic Acid, 1415-93-6, Triethylsilane, 617-86-7, Zinc Chromate, 13530-65-9.

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