Glossary of Silversmithing Terms

Since my last post was a glossary of common glassworking terms, I thought I'd cross over into my other major love, metalworking. These terms are some of the more common ones in silversmithing, copper smithing, jewelry forging, and the like.

Annealing: (Yes, just like in glass.) In metalwork, it's treating metal by heating it to red hot. It removes tension in a piece of metal, just like it does in glass, by allowing the molecules to resettle in a less crystalline formation. Working a piece of metal with steel tools causes it to become harder and harder (work-hardening), to the point it may become brittle. Annealing also makes the metal soft enough to run through rollers, emboss with patterns, or use in a draw plate.

Argentium Silver: Also called "Argentium Sterling". It's a newer alloy that has a higher resistance to tarnish than traditional sterling silver. Also reputed to be free from the concern of firescale. It's 92.5% fine silver, making it a genuine sterling silver, it just has different metals making up the non-silver 7.5%.

Burnishing: Rubbing the surface of the metal with a tool to make it shinier. Usually accomplished with a burnishing tool. However, tumblers technically burnish metal to make it shiny, rather than polishing it.

Chasing: Detailing the front of a piece of metal by using punches and metal chisels hit with a hammer.

Coin Silver: By legal definition, sterling silver is 92.5% pure silver. Coin silver has a more wishy-washy standard. It is the purity of metal theoretically matching that of contemporary silver currency. Over the years it has varied from about 83% to 92.5%. It's never been a legal standard like sterling, but was meant for silversmiths as a way to assure clients of the content of their silver.

Die Forming: Stamping or hammering a sheet of metal into a mold with the outline of your desired object. (Similar to die casting, where molten metal is poured into the mold.)

Drawbench/draw plate: A bench that has a plate with consecutively smaller die openings in various shapes (round, half round, square, triangular, etc.) A pair of rough toothed pliers is used to hold the end of a piece of annealed wire, which is then drawn through the plates to reduce the thickness/gauge.

Electroplating: Putting a metallic coating on metal or other conductive surface using a liquid bath and an electric current. Used to make materials more attractive, protect against corrision, or to make printing plates. Used by glass artists to add interest in the form of metal accents (there called electroforming, as it consists of building up a conductive surface on the non-conductive glass, then causing the surface to be plated.) The thickness of the plated layer depends on many factors, including the concentration of the "bath" solution, the length of time the item is left in the solution, and the strength of the electric current used.

Engraving: Cutting lines into metal, used for drawing, detailing, or writing. Sharp metal tools or electric gravers can be used.

Fine Silver: Fancy way of saying "pure silver." By legal definition, must be 99.9% pure silver. Much softer than sterling silver, it is usually only used for small decorative objects such as jewelry or commemorative coins.

Fire Brick: A porous, lightweight brick that can withstand the heat of soldering and brazing, as well as the heat of torching PMC.

Firescale: A marring that appears on the outside of non-ferrous metals that have been brazed without flux. Must be removed with pickle or by abrasion.

Firestain: Purple marring that comes out on sterling silver when the heat of soldering/brazing oxidizes the copper in the sterling. (Argentium does not contain copper, and does not firestain.) Acid can be used to chemically remove the oxidized copper, though there may still be staining beneath the surface.

Forging: To form by heating and hammering.

Hallmark: Not the card company. It's a mark (like a maker's mark) stamped or engraved by the assay office, indicating the quality of tested precious metal. Common marks include "925", "sterling", or a rampant lion used in Great Britain.

Liver of Sulfur: Chemical used to darken sterling silver purposefully. Generally purchased as a solid which needs to be mixed with liquid. Will turn the entire portion exposed to the Liver of Sulfur a deep black. Artists then often buff the patina off the raised portions. By leaving the dark patina in the crevices, it adds depth to a piece. Note: hot, freshly boiled egg yolks in a ziploc bag with the sterling will do the same thing. It just takes more time.

Maker's Mark: The artistic "signature" or name of the individual jeweler or silversmith, stamped into an object created by that maker. A "house mark" is similar, though it represents a company rather than an individual.

Mokume-Gane: Technique sometimes replicated in polymer clay work! In metal, it means different metals have been fused or brazed together in layers, then run through a rolling mill to make the material easier to work with. The working billets are punched, filed, and hammered to produce layered patterns.

Patina: In brief, it's a darkening or color change on a piece of metal. Many kinds of metal form a natural patina over time (a classic example is the way copper left out to the weather will turn green. The green is the patina.) It can also be used to refer to the fine scratches that objects acquier over time from being handled and polished, which causes the surface to appear differently than it did when the item was new. Often used to refer to a purposefully-induced color change, brought about by applying chemicals to the metal to change the surface colors or darken crevaces. "Liver of Sulfur" is one common way to patina silver to a deep black. Heating copper will create a multicolored darkened patina. Applying chemicals to do this is called "Patination" or simply "applying a patina".

Planishing: Hammering or refining the surface of a metal object with a highly polished, smooth planishing hammer. May be a decorative element. Planishing hammers must be kept highly polished to a mirror finish, and any contamination of the piece or the hammer face will mar the metal being hammered.

PMC (Precious Metal Clay): A clay substance formed by suspending recycled silver in a burnable medium. Common brands are PMC and ArtClay. The clay can be formed in similar fashion to pottery clay, and high-temperature stones can be incorporated before firing. Once the clay dries to the "greenware" stage, it can be filed, filled-in, or added-to. The clay is then finished by firing in a kiln (or with a butane or propane flame). The suspension medium burns out, the piece shrinks slightly as a result, and the object left is 99.9% pure silver, or fine silver. After firing, it can be cleaned and polished exactly as you would any other fine silver piece, and can be worked, have stones set in it, or anything else you would do with fine silver. Cannot be fired in a home oven, but some kinds can be fired on a fire brick with a butane torch.

Polishing: Does anyone really not know what polishing means? Can be done in a number of ways. One of the most common is to use a progression of increasingly fine-grained sandpaper to create a more smooth, matte surface on the object, then using a polishing wheel or hand polisher with increasingly fine grits of polishing compound (for example, jeweler's rouge, which creates a mirrorlike finish.) A rock tumbler filled with stainless steel shot or ceramic shot, plus a little mild dishwashing liquid or burnishing compound, can take the place of the use of the polishing wheel.

Refinish: Just like with furniture, it's making a metal object appear new(er) by removing scratches and imperfections, or even re-patinating.

Restore: See above. Repairing and replicating the original condition of the object.

Repoussé: Sort of the opposite of chasing. Roughly embossing metal from the back or from the inside surface with a larger punch/object than would be used in chasing the front/outside.

Rolling Mill: Hand driven or motorized mill with polished, hardened steel rollers that reduce the thickness of the sheet of metal. Can be used with patterned rollers, plates, or found objects to emboss texture onto sheet metal or wires. Looks much like a clothes-wringer or lasagna noodle press.

Scratch Brush: I just call this a "wire brush". Can either be a hand-held brush that looks like a wicked metal toothbrush, or can be wire disks on a dremel-type tool, or a wire wheel on a polishing wheel. Used to burnish the surface of metal after soldering. Can be used to create a matte/brushed finish on a piece of metal as well.

Silversmith: Person who creates silver objects and wrought/forged items like flatware.

Soldering: The lower-temperature version of brazing. Used to join low-temp metals. Most of the time when silver is joined with solder, it's merely called "soldering". However, silver is a higher temperature metal, and what is really being done when you "solder" silver is brazing. Solder comes in several forms: Sheet, wire, and liquid. It also comes in several "types". For example, the soft, wire-coil solder (available in several % of lead and lead-free varieties) used in stained glass will not work with sterling silver. Sterling silver solder is usually referred to as hard solder.

Soldering Pick: Usually made of tungsten, the pick will not stick to the solder, and is useful for moving around cold solder on a hot piece of metal, or for "dragging" the molten/flowing solder to a new area in the event that the solder has crawled to the wrong location.

Soldering Tweezers: These tweezers function backwards, meaning that when they are pinched, they open, and when they are released, they close. Makes it easier to hold tiny bits of solder, as you don't have to maintain pressure or worry about relaxing your hand and letting the solder bit drop.

Sterling Silver: Alloy of fine silver and copper (usually). By legal definition, must contain 92.5% fine silver. Fine silver is much softer than sterling, and is usually too soft for functional objects such as flatware, but it is sometimes used in jewelry. Any item stamped "925" or "sterling" must legally contain 92.5% silver.