About

Prof. Dr. Erhard Brepohl

Articles by


Prof. Dr. Erhard Brepohl

Article
Chain and Bracelet Catches 1

The first requirement of all catches is that they secure neckpieces and bracelets in such a way that they will not fall off the wearer. Once this is accomplished, there are other concerns that should be addressed. Making catches requires a high…

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Chain and Bracelet Catches 2

Box catches lend themselves to a wide range of shapes and are frequently used on chains, bracelets and cuff bracelets. They combine security with ease of use and the ability to be adapted to the needs of each design. After mastering the basics,…

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Cuttlefish Casting Method

Cuttlefish casting is a quick and fairly accurate casting method. Its applications are limited only by the thickness and overall dimensions of the shell. It is difficult to achieve fine details on the surface of the casting, but this is offset…

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Different Methods on How to Resize Rings

A ring fits well when it is no longer felt on the finger. If in the course of time the size of the finger changes or if the ring is to be fitted for another wearer, a sizing of the ring is necessary. The first step is to determine the finger size, which…

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Enameling Applications and Preparation

For more than two thousand years, goldsmiths have fused glass onto their work for color enrichment. Wonderful enameled work can be found from many ancient cultures, providing familiar icons of the technical skill and aesthetic sensibilities…

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Engraving Methods and Techniques

As important as the gravers are, it is hard to understate the importance of the devices used to secure work while engraving. Or to say it another way, even a properly sharpened graver in experienced hands will be difficult to use if the workpiece…

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Engraving Tools and Preparation

Many industries have need of specialized engravers, for instance those who make dies, who cut stones and glass, and others who carve reliefs. Though a goldsmith might call on a specialist for certain jobs, it is useful to have a general understanding…

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Goldsmithing Granulation Technique

The revival of granulation in our century has been accompanied by many wrong ideas and misunderstandings, many stemming from the incorrect notion that the secrets of a mysterious process were long lost. To better understand granulation,…

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Goldsmithing: Etching on Metal

Etching uses chemical corrosion rather than mechanical force to selectively remove metal. Simply put, the idea is to cloak parts of an object with an acid-proof paint then submerge the piece in acid. The caustic liquid eats away at exposed…

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Goldsmithing: Fusing Technique

When precious metal is heated to temperatures approaching its melting point there is a short span during which the outer layer or skin begins to melt while the interior remains solid. Or, to say the same thing technically, the interior remains…

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Goldsmithing: Repoussé and Chasing

The terms repousse and chasing are often confused and not without good reason since the two techniques are often worked together. One might as well think of ‘slipping and sliding’ to realize how difficult to establish a clear definition…

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Goldsmithing: Stone Setting Techniques

The pleasure and challenge of including gems in a jewelry object (beyond the intrinsic beauty of the gem, of course) is to resolve the various factors that come into play. A well designed setting must achieve several goals simultaneously –…

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Inlay Work

There are many techniques in which contrasting metals are placed side by side. Those that can properly be called inlay require a mechanical attachment to secure a soft material into a harder one.

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Metal Rolling and Drawing

Rolling can be thought of as a local, or isolated, deformation process during which thickness is decreased, length increased, and width remains unchanged. Drawing is different from rolling in that the pressure of drawing it not transmitted…

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Niello Metal Mixture

Niello is a deep black metal mixture that is fused onto metal for decorative effect. Though worked on three-dimensional objects, the effect might be considered graphic because it relies primarily on shape and pattern. The contrast of the…

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Precious Metal Refining

The principle of this ancient, valued procedure is described here because of its historical interest, and with the thought that young people coming into the field should be aware of the basic procedures of the trade, even though they may not…

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Sand Casting Method

Though sand casting has been largely replaced by centrifugal casting in recent decades, for hundreds of years it was the most popular of all casting methods. It still plays an important role in the production of large metal forms, and can offer…

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Special Repair Work

It is not uncommon for moving parts to wear out. This is to be expected because of increased friction as parts rub against one another. A common example can be found in connecting rings such as the jump rings that attach a charm to a bracelet or a…

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Testing Precious Metals and Alloys

The purpose of precious metal testing is to determine, first, whether a given sample is precious or base, and, second, to determine what proportion of an alloy is precious. Sophisticated equipment is used in a precious metal laboratory to…

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The Ancient Art of Fire Gilding

In the twentieth century there can be little doubt that electroplating is the best way to develop a gold coating on a metal object. It provides successful results in many colors and can be adapted to one-of-a-kind or mass production. Knowing…

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Understanding the Working Titanium

Because titanium behaves somewhat differently than the standard metals in the goldsmith’s workshop some special attention to its working is in order here. When sawing, begin the cut with a very light stroke, and increase the pressure only…

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White Metals and Alloys Testing

In practice an experienced eye will usually be able to determine by color and luster whether a piece is made of silver, a base white metal such as nickel silver, or a precious white alloy such as white gold or platinum. If this can be determined…