• Silver
Glossary •
• Silver
Glossary •
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An excellent resource for silver terminology is An Illustrated Dictionary of Silverware. Annealing: The heat treating (softening) of metal after it has been work-hardened with steel tools, and is necessary between raising and forging stages. Annealing is also used to remove tension in a piece of metal before brazing, helping to reduce warpage. Argentium Sterling: A new firestain-free alloy with fantastic tarnish resistance. It contains a higher percentage of fine silver (93%, and the higher 97% fine silver). It can be stamped sterling. More on Argentium can be found here. Assay: It is impractical for a refiner to refine each individual shipment of scrap separately. To keep the operation efficient, a sample is taken of each refining shipment to determine its precious metal content. Drilling samples are taken from each end of the bullion. The assay laboratory does a miniature refining process on the two samples to determine the precious content. The bullion karat is actually determined by the percentage of fine gold left following the assaying process. For example, 2-100 milligram samples are taken. The samples are wrapped in lead, placed onto cupels and put into a special assay furnace. As the samples become molten, the base metals, including the lead, vaporize or absorb into the cupels, leaving only the precious metal on top. The precious metal buttons are dissolved in the acid so that the gold content can be determined. The remaining samples are reweighed. If the 100 milligram samples now weigh only 50 milligrams, this means that there is 50% fine gold in the bullion. Brazing: A joining process whereby a filler metal or alloy is heated to melting temperature above 800 °F and distributed between two or more close-fitting parts by capillary action. At its liquid temperature, the molten filler metal and flux interacts with a thin layer of the base metal, cooling to form a strong, sealed joint. By definition the melting temperature of the braze alloy is lower (sometimes substantially) than the melting temperature of the materials being joined. The brazed joint becomes a sandwich of different layers, each metallurgically linked to the adjacent layers. When brazing sterling, care must be used to prevent firescale or firestain which is formed at higher temperatures than soldering. Bright-cutting: A form of engraving which uses polished gravers to produce very reflective cuts. Casting: A manufacturing process by which a liquid material is (usually) poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solid casting is then ejected or broken out to complete the process. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods. Chasing:The technique of detailing the front surface of a metal article by indenting with various hammer-struck punches. This process does not remove metal, but reshapes it. Chasing is demonstrated here. This technique is demonstrated in the second part of the video. Checking: The hammering down onto the edge of a form. This technique strengthens and visually thickens the edge. Coin Silver: Sterling is 925/1000 parts pure silver and is a legally enforceable standard. Coin is more variable; the purity of metal matching, in theory, that of contemporary currency. Occasionally, during periods of shortage, coins were literally used as metal stock, especially in the colonial era. Because of the multiplicity of coinage in use, it has varied from 835/1000 to 925/1000. It was never an enforceable standard like sterling, but was a means for silversmiths, lacking a national standard of assay, to assure clients of the quality of their silver. By the 1820s, with flat-rolled silver stock readily available, it became an arbitrary benchmark set at 900/1000 and remained so until the British sterling standard was adopted by Gorham, Tiffany, and others in the 1850s. Colloidal Silver: A liquid suspension of microscopic particles of silver. A colloid is technically defined as particles which remain suspended without forming an ionic, or dissolved solution. The broader commercial definition of "colloidal silver" includes products that contain various concentrations of ionic silver, silver colloids, ionic silver compounds or silver proteins in purified water. Colloidal silver with concentrations of 30 parts per million (ppm) or less are typically manufactured using an electrolysis process, whereas colloidal silver with higher concentrations of 50 ppm or more are usually either silver compounds such as silver chloride and silver iodide or are solutions that have been bound with a protein to disperse the particles. Currently, colloidal silver is marketed as an alternative medical remedy, though there is no scientific evidence of its effectiveness for any medical condition. Excessive use can result in argyria, a form of silver toxicity. I. History and Applications Prior to 1938, colloidal silver was widely promoted as a "cure-all," and silver products were prescribed by physicians as topical antibiotics. However, with the development of more effective, less expensive antibiotics such as penicillin and sulfanilamide, medical use of colloidal silver ceased. From approximately 1990, there has been a resurgence of the promotion of colloidal silver as an alternative medicine treatment, marketed with claims that it can prevent or treat numerous diseases. Colloidal silver products are legally available at health food stores in the United States and Australia and are marketed over the Internet as a dietary supplement. It is illegal in the U.S. and Australia for marketers to make claims of medical effectiveness for colloidal silver, but some websites still list its use for the prevention of colds and flu, and the treatment of more serious conditions such as diabetes, cancer, chronic fatigue syndrome, HIV/AIDS, and tuberculosis, among other diseases. Colloidal silver has been found to lack any antimicrobial effect, and there is no medical evidence that colloidal silver is effective for any of these claimed indications. Silver is not an essential mineral in humans; there is no dietary requirement for silver, and no such thing as a silver "deficiency." Currently, there are no evidence-based medical uses for colloidal silver. There are no clinical studies in humans demonstrating effectiveness, and several reports of toxicity. The U.S. National Center for Complementary and Alternative Medicine has issued an advisory indicating that the marketing claims made about colloidal silver are scientifically unsupported, and that the silver content of marketed supplements varies widely and can pose risks to the consumer. II. Toxicities and Interactions: Argyria Excessive intake of silver products may result in a condition known as argyria, one symptom of which is blue or gray discoloration of the skin. The discoloration occurs when silver is deposited in the skin and then darkened by sunlight, just as silver particles in photographic film darken when exposed to sunlight. Localized argyria can occur as a result of topical use of silver-containing remedies, while generalized argyria results from the ingestion of colloidal silver. Arygria is usually permanent, and there is no known effective treatment. While argyria is usually benign and limited to skin discoloration, there are isolated reports of more serious neurologic, renal, or hepatic complications. A death has been reported in the medical literature as a result of colloidal silver use; in that case, a 71-year-old man developed status epilepticus which the authors felt was due to silver toxicity. A number of case reports describe argyria after ingestion of colloidal silver marketed as an alternative-medicine treatment. Colloidal silver may theoretically interact with some medications, including tetracycline and quinolone antibiotics and penicillamine, reducing the effectiveness of those medications. III. Government Regulation In August 1999, the U.S. Food and Drug Administration (FDA) banned colloidal silver sellers from claiming any therapeutic value for the product, noting that such products were being marketed for numerous diseases without evidence of effectiveness. The FDA also banned over-the-counter sale of drug products containing colloidal silver due to the lack of safety or efficacy data. The product now has the status of a dietary supplement in the US; it can be promoted with general "structure-function" claims, but cannot be marketed as preventing or treating any illness. Following this ruling, the FDA has issued numerous warnings to Internet sites which have continued to promote colloidal silver as an antibiotic or for other medical purposes. In 2002, the Australian Therapeutic Goods Administration (TGA) ruled that colloidal silver-containing products were no longer exempt from therapeutic goods legislation and had to meet the requirements of other products covered by this law. The TGA found that "there are no current legitimate uses of colloidal silver and that the Surveillance Section of the TGA be requested to investigate the illegal availability of colloidal silver products because of concerns about their significant toxicity. The reasons for the recommendation were that: There is little evidence to support therapeutic claims made for colloidal silver products; the risk to consumers of silver toxicity outweighs the value of trying an unsubstantiated treatment, and bacterial resistance to silver can occur; and efforts should be made to curb the illegal availability of colloidal silver products, which is a significant public health issue. Additional information on colloidal silver's dangers can be found Quackwatch, Dr. Andrew Weil, and Rosemary's Story. Conservation: Primarily dealing with cleaning an object, doing the least amount of harm to its original finish. Crimping: A rapid raising process by forming radiating valleys from the center to the outer edge of a metal object then raised. Generally used on thinner gauge metal. Cross-Peen Hammer: Hammers with long, narrow faces running perpendicular to the handle and used for raising, forming, and planishing. Die Forming: The process of stamping or hammering a sheet of metal into a form which has the outline of the object. Also used when making duplicate objects. Drawbench: A narrow, waist-high bench equipped with a chain dragging a pair of drawtongs (large coarse-toothed pliers) used to grip the end of a piece of wire. This wire is then pulled through a series of consecutively smaller dies (round, square, triangular, etc.) reducing its thickness. Patterned dies may also be used to produce moldings, boarders, etc. Electroplating: The process of putting a metallic coating on a metal or other conducting surface by using an electric current. It is used to improve the appearance of materials, for protection against corrosion, and to make plates for printing. The article to be plated is thoroughly cleaned of grease and dirt by dipping it in acid and alkaline cleaning solutions. It is then put in a solution of the metal with which it is to be coated. The metal exists in the form of positive ions (atoms that have lost one or more electrons). The article is connected to the cathode (negative end of a source of electricity). The anode (positive electric terminal) is connected to another conductor which is also dipped into the solution. The electric current acts on the metallic ions in the solution. The ions are attracted to the cathode, and the coating is deposited on the article's metal surface. If the metal in the solution and the metal of the positive terminal are the same, the electricity may remove metal from the terminal to replace metal taken from the solution. The thickness of the layer deposited on the article depends on the strength of the electric current, the concentration of metallic ions, and the length of time the article has been in the solution. The terms triple-plated and quadruple-plated indicate various thicknesses of plating, not separate layers deposited on the surface. Ornamental and protective platings are very thin, usually from 1/1,000 to 2/1,000 of an inch (0.03 to 0.05 millimeter) thick. For plating gold, silver, copper, zinc, and cadmium, cyanide solutions of the same metals are often used. Copper and zinc may also be plated by acid-sulfate solutions. Chromium is plated with a chromic-acid solution and nickel is plated with nickel sulfate. Other metals plated for commercial use include platinum, lead, and tin. Alloys of two or more metals may be deposited by using a solution of salts of the metals that make up the alloy. Examples of alloys used for plating are brass, black nickel, lead-tin, and bronze. Electroplating is also used to reproduce medals or other objects in a process called electroforming. This process was formerly known as galvanoplasty. One kind of electroforming, called electrotyping, is the reproduction of type forms and engravings for the printing industry. Resource: Melvin Bernstein, "Electroplating," Discovery Channel School, original content provided by World Book Online, http://www.discoveryschool.com/homeworkhelp/worldbook/atozscience/e/177500.html, 11/15/2001 Engine Turning: An engraving technique in which a very precise intricate repetitive patterns or design is mechanically engraved into an underlying material with very fine detail. It is engraving on a two- or three-dimensional surface with a diamond stylus cutting very specific designs, mostly linear. You've probably seen examples engine turning on card cases, money clips, and dresserware. Engine turning is also called guilloché after the French engineer “Guillot,” who invented a machine “that could scratch fine patterns and designs on metallic surfaces.” Engine turning machines were first used in the 1500-1600's on soft materials like ivory and wood and in the 1700's it was adopted for metal such as gold and silver. The last machines were manufactured around 1948-1949. The machine improved upon the more time-consuming practice of making similar designs by hand, allowing for greater delicacy, precision, and closeness of the line, as well as greater speed. Find more information on engine turning and to see videos, go here. Engraving: The process of cutting shallow lines into metal with a sharp graver, reproducing artwork which has been drawn on a metal article. Unlike machine engraving, hand engraving removes metal when cutting. See a video here. EPNS: Electro Plated Nickel Silver. Etching: A process of dissolving metal with acid, leaving a recessed design. The upper, unetched surface is sometimes engraved. Finishing: Processes, accomplished either by hand or mechanical device with suitable compounds, to produce a desired surface. Firescale: A scale that developes on the outer surface of a non-ferrous objects without protective flux during brazing. The scale must then be removed chemically or by abrasive methods. Firestain: Oxidized copper in solid silver that can be found on many pre-colonial through early twentieth century pieces. If, after cleaning your silver (not silverplate) piece, a purplish stain remains, do not mistake this stain (cuprous oxide) for tarnish! Attempting to remove it will only damage your prized piece. It is not generally seen on pieces that have been produced by the large American silver companies after the early 1900s, but many one-person silversmithing shops still use this technique. I will not get into the technicalities of firestain here, but the stain is usually obscured with fine silver either by silverplating the object or through a process called depletion. The firestain under this fine silver layer, which may be a few thousandths of an inch thick, may not show up until after many years of polishing. Fold Forming: Fold forming is a new, quick, easily learned way of shaping sheet metal with hand tools. Forms are derived from the natural plasticity and ductility of the metal. Lewton-Brain invented fold-forming, which is internationally recognized as a new way to work metal. Shaping is extremely efficient and rapid (many take 3-7 minutes working time). Tools are simple: fingers, hammers, anvil, and mill. Complex relief forms are made from sheets of metal often on one annealing. They resemble chased, constructed, and soldered forms, and can be made with most metals, including steel. Forging: A process that has as its primary purpose: the alteration of the original thickness and cross-section of metal. This is usually through hammering wire, rods of metal, ingots (as would be forged into sheet by modern day Colonial Williamsburg silversmiths), or heavy sheet stock (for forming most flatware). Forming: A process which has as its primary purpose: altering a sheet of metal so that it changes planes, three-dimensionally. Changes in the metal's thickness are incidental by-products of the process of forming. Fused Plate: Excerpted and edited from Sheffield Plate: Its History, Manufacture and Art by Bertie Wyllie (London, 1908). Sheffield plate [fused plate] is the name applied to a variety of articles of domestic use or ornament, made of copper coated with silver by a special and now abandoned process. Many of them were actually manufactured in Birmingham, but as the secret of producing the material was discovered and brought to perfection in Sheffield, the name of that town was naturally connected with it, and thence transferred to articles constructed from it. In 1742 a workman named Thomas Bolsover was mending the handle of a knife made of silver and copper, when, accidentally overheating it, he caused the metals to fuse and flow, and found that as a consequence the silver adhered to the copper as a thin coating. Being an intelligent man, he perceived the commercial value of his chance discovery, and began the manufacture of articles which, with all the appearance of silver, were both cheaper and stronger than those made of the pure metal. He apparently, however, confined himself to applying the silver direct to the surface of the copper after the latter had been given the shape destined to it, and was thus limited to the production of small articles such as snuffboxes, knife handles, toilet articles, etc. It was reserved to Joseph Hancock to realize that by making the plate first and working it into the desired form afterwards he could almost indefinitely extend the possibilities of the material. The process in its final and highest development was as follows. The groundwork was a mixture of copper and brass, either metal alone having serious defects. This was cast into an oblong ingot, one to 12 inches in thickness, 21 inches in breadth, and of a length regulated by the size of the plate desired. The surface of this was brought by planing, grinding and other means to the highest possible pitch of smoothness and evenness. A sheet of silver of a finer quality than standard, with a thickness up to one inch according to the quality aimed at, and of the same superficial extent as the copper bar, was leveled and polished in the same way and accurately fitted to it, neither surface at any time being soiled by contact with the workman's fingers. A sheet of copper, rather smaller than the other two and in. thick was laid upon the silver, and on the top of all was added a piece of iron, four inches thick, one inch wide, and a little shorter than the three others, to protect them from the direct contact of the strong iron wire with which all were firmly bound together. The junction of the edges of the silver and copper blend was treated with a flux of borax and the whole was submitted to the heat of a furnace until the silver was seen to be melting, when it was instantly removed, care being taken to avoid pressing upon the upper or lower surfaces, as the liquid silver in that case would have been squeezed out from between the two enclosing plates and the operation ruined. It was then left to cool, and after being thoroughly cleansed presented the appearance of a copper ingot with one silver side. This was passed again and again between gradually approximated rollers, with occasional annealing, until the desired thickness had been attained. The great extension of surface thus produced had the drawback of exaggerating any small defect in the union of the two metals, increasing it to a blister of an inch or more in diameter. It was, however, fortunately found easy to remedy this. The blister if unbroken was heated, pricked, and then rubbed level with a burnisher; if, as sometimes happened, the silver had flaked away it was replaced by coatings of pure leaf silver rubbed in with a burnisher. The plate when passed as flawless was cut into the desired form and molded as far as possible into shape, the edges where necessary being soldered. At first only one surface of the copper was plated with silver and thus its usefulness was necessarily restricted, but it was a simple matter to apply the silver to both sides and thenceforward whatever was made in solid metal could be reproduced in plate, and firm after firm went into the business, ever and anon introducing further improvements. The possibility of embossing the metal beyond a certain point without fracturing the coating of silver was remedied by casting or stamping the raised ornament in silver, filling the hollows with a form of pewter, and soldering the result to the appropriate part of the general design. Another difficulty, the concealment of the inner core of copper which was seen as a thin red line when a cut edge was exposed, was met about 1784 by George Cadman, who adopted the practice of soldering on an edging, generally ornamented, of solid silver so as to cover the junction, and the presence of this is one of the trustworthy tests by which genuine Sheffield plate may be recognized. The labor of rolling the metal by hand was done away with about 1760, by the firm of Tudor, Leader & Sherburn, who first employed horse-power, and for more than half a century the trade both in Sheffield and Birmingham continued to flourish. In 1736 there were under 10,000 inhabitants in the former city; in 1760 when Horace Walpole passed through it, buying for two guineas a pair of candlesticks of the local plate, which he thought "quite pretty," and pronouncing it to be "one of the foulest towns in England," there were two-and-twenty thousand who remitted eleven thousand pounds a week to London. It would be impossible, were it desirable, to enumerate all the varieties of the articles turned out, or to overpraise the beauty and elegance of most of them. The designs were identical with those in favor with the gold and silversmiths of the period, which was happily one when exceptionally good taste prevailed. The appreciation of light and well-proportioned curves and the skilful employment of well-contrived pierced work are conspicuous features. The success was, however, doomed to be short lived and to come to an end as swiftly as it had grown up. In the year 1800 W. Cruikshank was already experimenting with a process of electro-plating, and in 1837 Mr. Spencer in England, and in 1838 Professor M. H. Jacobi (1801-1874) in Russia, working independently, succeeded in contriving methods which could be made commercially profitable. Two years later Messrs Elkington in London and M. de Ruolz of Paris started in business on those lines, and the slower and consequently more costly manufacture at Sheffield and Birmingham rapidly died out. Of recent years old Sheffield plate after long neglect has come into fashion again, and genuine articles in good condition have greatly gone up in value, often exceeding in cost those of more modern date in sterling silver. Concurrently fraudulent imitation has regrettably increased. In some cases the whole object is a modern reproduction in electro-plate, but more often really old articles from which the original plating has been worn off in course of time have been replated, both equally being in the eyes of the connoisseur, unworthy of serious attention and comparatively valueless. The difference after a little experience is not difficult to detect, though inexpressible in words. The pressure to which the Sheffield plate was submitted produces a definite color and texture which is absent from the surface produced by the deposit of silver in a liquid medium by electrical means, and the coat of silver is spread by the latter uniformly over the whole surface without a break, while in the former the junction between the embossed ornaments and the silver strips covering the cut edges may often be detected on careful examination. Guilloché: See Engine Turning Gilt: Gold plating over the entire surface of a silver (not silverplated) object. Objects that are partially goldplated are called parcel gilt (or partially gilt). Hallmark: A mark or series of marks stamped or laser-engraved by a country's assay office indicating the quality of the precious metal tested (e.g., "Sterling," ".925," ".840," ".800," or an image of a "rampant lion"—indicating sterling as used in Great Britian). The object may also contain the country, assay office, maker's mark, housemark, duty mark, etc. Much more on hallmarks can be found here. Head: A short, polished, cast metal mushroom-type stake that fits into a horse and is used for planishing and burnishing metal objects over. Horse: Held in a vise, this straight or L-shaped holding devise accommodates heads. The length of a horse varies depending on the size or depth of the piece being fashioned. House Mark: A mark stamped or laser-engraved by the company (e.g., "Gorham," "Reed & Barton," "Tiffany," "Kalo") that created the object for its own line or for a retailer (e.g., "Shreve, Crump & Low," "J.E. Caldwell Co."). In addition, there may also be a maker's mark, indicating the company's craftsman who created or oversaw the creation of the object. Insulators: Coffee and teapots are normally found with ivory, plastic, hardwood, or compressed fiber positioned between the body and handle to block heat transfer of the liquid to the handle. Insulators can also be found on other objects, such as water kettles and burners, that may transfer heat to the handle. Laser Welding: A technique used to join or fill metal through the use of a laser. The beam provides a concentrated heat source, allowing for narrow, deep welds and high welding rates. Maker's Mark: The name or artistic mark stamped, engraved, or laser-engraved on an object created by an individual silversmith or jeweler. Model Making: Numerous processes and materials used to produce casting patterns that will then be duplicated in metal. Mokume-Gane: Laminated metals that have been fused or brazed together like a sandwich, and passed through a flat or wire-forming rolling mill to make the material easier to fabricate or raise. The sandwich or "billet" can also be forged without the use of the rolling mill. Patterns are then punched, filed, and hammered to produce a desired pattern. Niello: A black metallic alloy of sulfur, copper, silver, and usually lead, used as an inlay on engraved metal. It can be used for filling in designs cut from metal. The Egyptians are credited with originating niello decoration, which spread throughout Europe during the Middle Ages. Patina: Patina can mean three things: 1. The fine scratches on an object that have developed over time from handling and polishing, 2. The natural darkening that is seen in the recesses of ornamental pieces and engraving, 3. A factory-applied chemical used to darken the recesses of a design to enhance its details and give it a three-dimensional look. Patinate / Repatinate: To apply or reapply a chemical to darken the recesses on ornamental pieces and engraving that had naturally developed over time. This process is sometimes applied to objects that have had their darkening removed from dishwashers or chemical strippers such as Tarn-X. Planishing: The act of hammering or refining the surface of a metal object with highly polished hammer faces. This process refines the surface after raising and may be used as a decorative element. Great care must be used, for even a speck of dust will make an impression in the metal being hammered. Polishing: The process of refining a metal surface by use of abrasive compounds applied by hand or a polishing wheel attached to a long-spindled motorized arbor which runs at high speed. Various finishes may be obtained with a wide variety of abrasive compounds applied to the polishing wheels such as rouge–this compound imparts the brightest finish. More abrasive compounds will produce less reflective finishes, emphasizing the object's form. Preservation: To stabolize an object from further deterioration. This may entail using an archival wax to maintain the surface finish. Raising: The technique of forming a flat sheet of metal over a cast iron T-stake or head, forming and compressing the metal to take a hollow form. This labor-intensive process is the purest form of silversmithing. Refinish: To make an object look new by removing all scratches and imperfections. Repair: To fix (best possible outcome) a damaged or worn area on an object. Repatinate: See Patinate. Repoussé: A technique used to roughly emboss a metal object with ornament from the back or inside with larger punches than those used in chasing. This process does not remove metal, but reshapes it. Repoussé is demonstrated here. The technique is demonstrated in the first part of the video. Restoration: To either make an object or damaged area on that object look new, or to make it look its age without any noticeable damage or repairs. Restore: To repair and finish an object to its original condition. Rolling Mill: A hand or motor-driven cast iron mill with polished or patterned hardened steel rollers that reduce the thickness or impart a texture on metal sheet or wire. Functions like a hand cranked clothes ringer. Scratch Brush: A long-spindled motorized arbor using fine wire wheels rotating at slow speed, burnishing the surface of a metal object after soldering. Soapy water is used as a lubricant between the wheel and object. May also be used as a texturing wheel to soften the luster of metal. Sheffield Plate: See Fused Plate
Silver
Silver as an Antimicrobial Silver is widely used in topical gels and impregnated into bandages because of its wide-spectrum antimicrobial activity. The antimicrobial properties of silver stem from the chemical properties of its ionized form, Ag+. This ion forms strong molecular bonds with other substances used by bacteria to respire, such as molecules containing sulfur, nitrogen, and oxygen. Once the Ag+ ion complexes with these molecules, they are rendered unusable by the bacteria, depriving it of necessary compounds and eventually leading to the bacteria's death. Silversmith: One who fashions silver objects and wrought items such as forged flatware. The first silversmiths who settled in this country set up our banking system and produced its first coinage. Sinking: The hammering of a flat piece of metal into a concave hemispherical shape in the top of a tree stump or any dished form. A small bowl shape is formed in the center of the sheet producing a lip, enabling the piece to "ride" the end of a raising stake, aiding in the raising process. Snarling: The embossing from underneath or inside an object with a long-armed steel tool, with one end placed in a vise. Snarling is accomplished by placing a form over the snarling iron's tip (which may be any shape) and tapping the back end of the arm which is secured in the vise. The vertical vibration that results gives a "kick," raising a bump on the outside of the object. This technique is usually used in conjunction with chasing. Soldering: A process in which two or more metal items are joined together adhesively, by melting and flowing a filler metal into the joint, the filler metal having a relatively low melting point. Soft soldering is characterized by the melting point of the filler metal, which is below 800 °F. The filler metal used in the process is called solder. Soldering is distinguished from brazing by use of a lower melting-temperature filler metal; it is distinguished from welding by the base metals not being melted during the joining process. In a soldering process, heat is applied to the parts to be joined, causing the solder to melt and be drawn into the joint by capillary action and to bond to the materials to be joined by wetting action. After the metal cools, the resulting joints are not as strong as the base metal, but have adequate strength, electrical conductivity, and water-tightness for many uses. This technique does not possess the strength of brazing solders when joining higher temperature metals such as silver. Spinning: Spinning, a technique that originated in the early 19th century, can be used for most metals. A metal disk is set on a lathe behind an appropriately shaped metal or wooden chuck, and during rotation the metal is pressed onto the chuck with long-handled, polished steel tools.. Britannia metal was often spun; a typical, modern spun object is the aluminum saucepan. As in most metalworking techniques, the metal is periodically softened by annealing, or heating, when it has become hardened through being worked. See a video here and here. Spring Hammer: A 5' cast iron beam supporting a long-handled, highly-polished pivoting hammer with a 3" diameter face. The hammer is mounted on a spring mechanism allowing the hammer head to bounce off a highly polished adjustable anvil used to flatten the bottoms of trays and anything else that requires a perfectly flat surface. The spring hammer head bounces off the anvil perfectly flat, avoiding a costly crescent-shaped miss-hit of a hand-held hammer head's edge. Stainless Steel: This is essentially a low carbon steel which contains at least 10% chromium by weight. It is this addition of chromium that gives the steel its unique stainless, corrosion-resisting properties. The chromium content of the steel allows the formation of a rough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. If damaged mechanically or chemically, this film is self-healing, providing that oxygen, even in very small amounts, is present. The corrosion resistance and other useful properties of the steel are enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel and nitrogen. Better quality stainless flatware contains 18% chromium and 8% nickel. Carbon steel rusts when exposed to air and moisture. This iron oxide film (the rust) is active and accelerates corrosion by forming more iron oxide. Stainless steels have sufficient amounts of chromium present so that a passive film of chromium oxide forms which prevents further surface corrosion and blocks corrosion from spreading into the metal's internal structure. Harry Brearley of the Brown-Firth research laboratory in Sheffield, England, is most commonly credited as the "inventor" of stainless steel. In 1913, while seeking a corrosion-resisting alloy for gun barrels. Stake: Any polished cast iron or steel tool placed in a vise and is used for forming and planishing metal over. This tool is generally large enough to be used without a horse. Sterling Silver: An alloy of fine silver (92.5%) and copper (7.5%) most commonly used when fashioning holloware and flatware because of its strength. Fine silver (99.99% pure) is generally too soft when producing large functional objects. U.S. law states that all objects marked "sterling," "925" or "925/1000" MUST contain no less than 92.5% fine silver. Surface Gauge: A vertical steel rod mounted with an adjustable arm fastened to a heavy base. The adjustable scribe-type pivoting arm can be raised or lowered to check the height or to scribe a level line around an object in order to mount a wire or anything else that must be level. Often used on top of a surface plate. Surface Plate: A perfectly level steel, cast iron or granite table of any dimension; used to check the level and flatness of an object. Often used in conjunction with the surface gauge. T-Stake: Any polished, cast iron or steel tool in the form of an elongated "T" and used in a vise for raising, forming or planishing metal. Vermeil: See Gilt Weighted Sterling: Reinforced holloware and dresserware. These pieces are most often filled with pitch, but may also contain plaster, lead, or some other material because the metal can be as thin as .003". If these pieces were not weighted, they would almost collapse! The total weight of the silver alone in a large candelabra may be as low as a few ounces. Weighted objects have been produced for decades, allowing more consumers to afford silver. In most cases, objects of this type are impractical because their structural integrity often suffers with daily use and cleaning. |
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