Vitreous enamel

This is a commonly used, yet fanciful term, implying that an ordinary latex or oil-based paint has the same properties as true, fired enamel. This detail has occasionally been used in folktales such as The Three Little Pigs in which the wolf comes down the third little pig's chimney, and in Alice's Adventures in Wonderland where Bill the lizard is sent down the White Rabbit's chimney to get Alice out of the house. Some paints are called "enamel paints". The story of Santa Claus teaches that he comes down the chimney to get in the house. This produces tiny specks of both colours; although the eye can be tricked by grinding colors together to an extremely fine, flour-like, powder. This type of chimney often shows vertical cracks on the exterior of the chimney which worsen as the internal rebar rusts. Different enamel colours cannot be mixed to make a new colour, in the manner of paint. Fundamental flaws (the difference in thermal expansion rates between steel rebar and concrete which caused the chimney flues to crack when heated) bankrupted the US manufacturers and obsoleted the technique.

Enamel can be either transparent, opaque or opalescent (translucent), which is a variety that gains a milky opacity the longer it is fired. Reinforced Concrete Chimneys: Popular during the 1970s to 1980s. The last creates delicate shades ranging from pure violet through wine-red and warm gray. Unreinforced masonry chimney do not stand up to earthquakes well. Color in enamel is obtained by the addition of various minerals, often metal oxides cobalt, praseodymium, iron, or neodymium. Tiles are used to line the flue to keep the corrosive combustion products from eating away that the chimney flue lining. Some techniques of enameling:. Masonry (brick or stone fireplaces and chimneys) with or without tile lined flue.

According to some sources, the word enamel comes from the High German word smelzan (to smelt) via the Old French esmail. Otherwise it's a good alternative to the more costly masonry chimney. Enameling was a favorite technique of the Art Nouveau jewellers. Within a hundred yards or so of salt water this type of chimney tends to rust out. The bright, jewel-like colors have also made enamel a favored choice for designers of jewelry and bibelots, such as ancient beads, the fantastic eggs of Peter Carl Fabergé, enameled copper boxes of Battersea enamellers, and artists such as George Stubbs and other painters of portrait miniatures. Manufactured or 'Prefab' fireplace with sheet metal fire box and double or triple walled metal pipe running up inside a wood framed chase with a chase cover and cap/spark arrestor at the top to keep the birds out and the sparks in. Other practitioners include the ancient Greeks, Celts, Russians, and the Chinese. Types of fireplace include:.

The ancient Egyptians applied enamels to pottery and stone objects. A fireplace consists of foundation, hearth, firebox, facing, ashdump door, cleanout door, lintel, lintel bar, breast, damper, smoke chamber, throat, flue, chimney chase, crown, cap or shroud, and spark arrestor. Enamelling is an old and widely-adopted technology. They also cost a lot more to build. The durability of enamel has given it many functional applications, including: early 20th century advertising signs, interior walls of ovens, speckleware cooking pots, exterior walls of high quality kitchen appliances, cast iron bathtubs, storage silos on farms and process equipment such as chemical reactors and tanks for the chemical and pharmaceutical process industries. Brick or stone fireplaces have greater durablity and can be designed to meet exact specifications for opening size, depth, and facing material. Disadvantages are its tendency to crack or shatter when the substrate is stressed or bent. Prefab fireplaces have become popular because of their lower construction cost but offer a limited range of sizes and styles.

Vitreous enamel has many excellent properties: it is smooth, hard, chemically resistant, durable, can take on long-lasting, brilliant colors, and cannot burn. This is so the fireplace doesn't suck out warm air. Also, an "enamel" is a decorative object, usually very small, having an enamel coating, such as a piece of champlevé or cloisonné. Some fireplaces have been closed off not allowing them to be used, either the top of the chimney has a concrete slab installed over it or the bottom has had a board nailed to it. Vitreous enamel can be applied to most metals. Many lower priced new homes are not equipped with a fireplace at all, its heating function long since taken over by central heating and its social function by the home entertainment center. It is often applied in a paste form and may be transparent or opaque when fired. Alternatively, flame-shaped paper streamers wave vertically in the air, held up by the updraft produced by a heating element.

The powder melts and flows to harden as a smooth, durable vitreous coating on metal, glass or ceramic. Gas fireplaces very often burn off a small amount of their fuel in a flickering display meant to recall that of a wood fire. In a discussion of art technology, enamel (or vitreous enamel, or porcelain enamel in American English) is the colorful result of fusion of powdered glass to a substrate through the process of firing, usually between 750 and 850 degrees Celsius. In many places, coal, wood or peat burning fires are being replaced by cleaner, safer and often cheaper gas and electric fires. Counter enameling, not strictly a technique, but a necessary step in many techniques, is to apply enamel to the back of a piece as well - sandwiching the metal - to create less tension on the glass so it does not crack. One famous use of this tradition in the United States during the Great Depression was President Franklin Delano Roosevelt's "fireside chats", weekly radio addresses in which he made use of the family gathering time to state his views on issues of national importance. Sgrafitto, where an unfired layer of enamel is applied over a previously fired layer of enamel of a contrasting color, and then partly removed with a tool to create the design. After the workday, it is often the place a family meets at night before retiring to sleep.

The stencil is removed before firing, the enamel staying in a pattern, slightly raised. As a result, people then and now gather around a fireplace for conversation, planning, or celebration in a more intimate fashion. Stenciling, where a stencil is placed over the work and the powdered enamel is sifted over the top. The sensation of direct heat, and the mesmerizing leaps and flickers of a wood fire, make its use enjoyable in cold conditions even today. A 3D type of enameling where a sculptural form is completely or partly enameled. In colder climates throughout the world, the fireplace or hearth has traditionally been the central feature of the household, as it gives warmth to aid survival through an extended winter. Ronde bosse, French for "round bump". A chimney or other vent allows gas and particulate exhaust to escape the building.

It has a stained-glass like appearance. A fireplace is an appliance built into many homes, consisting of a space designed to contain an open fire, generally for heating but sometimes also for cooking. Plique-à-jour, French for "braid letting in daylight" where the enamel is applied in cells, similar to champlevé, but with no backing, so light can shine through the transparent or translucent enamel. It is a form of Grisaille. Limoges, named after the town in France where it was invented, is the technique of "painting" with an especial enamel called "blanc de limoges" over a dark enamelled surface to form a detailed picture, often human figure.

Grisaille, French term meaning "greying", where dark, often blue or black background is applied, then limoges or opalescent (translucent) enamel is applied on top, building up designs in a monochrome gradient, paler as the thickness of the layer of light color increases. Cloisonné, French for "cell", where thin copper, silver or gold wires form walls which separate different areas. Champlevé, French for "raised field", where enamel is fired around raised fields of metal, leaving the metal exposed. The surface of the metal is decorated with a low relief design which can be seen through translucent and transparent enamels.

Basse-taille, from the French word meaning "low-cut".