The Project Gutenberg EBook of How to Enamel, by Howard M. Chapin This eBook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org. If you are not located in the United States, you'll have to check the laws of the country where you are located before using this ebook. Title: How to Enamel Being a Treatise on the Practical Enameling of Jewelry with Hard Enamels Author: Howard M. Chapin Release Date: July 10, 2020 [EBook #62603] Language: English Character set encoding: UTF-8 *** START OF THIS PROJECT GUTENBERG EBOOK HOW TO ENAMEL *** Produced by The Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) HOW TO ENAMEL BEING A TREATISE ON THE PRACTICAL ENAMELING OF JEWELRY WITH HARD ENAMELS BY HOWARD M. CHAPIN AUTHOR OF “LIFE OF DEA. SAMUEL CHAPIN,” ETC. FIRST EDITION FIRST THOUSAND NEW YORK JOHN WILEY & SONS London: CHAPMAN & HALL, Limited 1911 Copyright, 1911 BY HOWARD M. CHAPIN Stanhope Press F. H. GILSON COMPANY BOSTON, U.S.A. CONTENTS Page List of Illustrations v Preface vii Introduction ix CHAPTER I Preparation of the Enamel 1 CHAPTER II Preparation of the Metals 8 CHAPTER III Charging 14 CHAPTER IV Firing 23 CHAPTER V Stoning 29 CHAPTER VI Polishing 37 CHAPTER VII Foils—Paillons—Glitter Enamel—Dull Finish—Plique-à-Jour 42 CHAPTER VIII Enamel Painting 50 CHAPTER IX Photographs on Enamel 57 iii LIST OF ILLUSTRATIONS FIG. PAGE 1 Agate Mortar and Pestle x 2 Grinding with Weighted Pestle 2 3 Enameler’s Spatula with Wooden Handle 10 4 Charging 14 5 Metal Tray and Tile 24 6 Firing 30 7 Carborundum or Emery Stone 37 8 Stoning 44 9 Pickle Pan 51 10 Polishing 58 11 Pickle Pot 65 v PREFACE The aim of this book is to explain practical enameling in such a way that one entirely unacquainted with the subject will, after a little study, not only understand the fundamental principles of the art, but with a little practice be able actually to achieve creditable results in this most fascinating branch of the jeweler’s craft. vii INTRODUCTION Enamel is really a glaze applied to metals just as other glazes are applied to porcelain, glass, and earthenware. We will confine our attention to what is known as hard enamel in contradistinction to japans, lacquers, and enamel paints, which are often called soft enamels. Hard enamels are compounds of glass with different metallic oxides which produce the different colors. These compounds are fused together at a very high temperature and on cooling become extremely hard. They fill the gap between glass and china, the transparent fondants being to the layman indistinguishable from glass, while the opaque whites may be easily mistaken for china, and the countless other varieties form a chain of scarcely perceptible gradations from one extreme to the other. Fig. 1. Agate Mortar and Pestle. The use of enamels is both very ancient and very widespread, for we find the process known to the ancient Egyptians and to the Chinese, although the highest development in the art was reached in France in the sixteenth century. We would refer the historical student to Cunynghame’s “European Enamels” in English and Luthmer’s “Enamel” in German. Jewelry enameling is usually divided into five different classes, viz: champlevé, cloisonné, incrusted, plique-à-jour, and enamel painting. Champlevé enamel is that in which a part of the metal is cut away, leaving a depression which is filled with enamel to the level of the surface of the metal, thus giving a sort of inlaid effect. If the enamel surface is not filed off flat but allowed to have a concave or convex surface the piece is said to be “flushed.” Technically enamel is “flushed” if it is not “stoned.” When transparent enamels are used and the background under the enamel is cut in relief, it is called “Baisse- taille enamel.” Cloisonné enamel is hardly distinguishable from champlevé when finished, but is made differently. Instead of cutting depressions in the metal to hold the enamel, metal wires are soldered on the smooth surface of the metal, thus forming partitions or fences between which the enamel is placed. Incrusted enamel is that in which the enamel is charged directly on the metal surface without any raised metal edges to hold it. It is generally used in small daubs or beads to reproduce the effect of precious stones. Plique-à-jour enamel is similar to cloisonné except that the wires are soldered to each other without any background, thus forming a sort of filigree, the spaces within which, when filled with enamel, somewhat resemble a stained-glass window. In enamel painting a picture is painted on the enamel. Usually white opaque enamel is used for the background, and the painting is executed with finely ground enamel or china paints, after which it is covered with a layer of transparent enamel which serves as a protection for the painting. ix x xi xii CHAPTER I PREPARATION OF THE ENAMELS Enamel is generally bought in the form of hard chunks more or less flat and varying from the size of an acorn to that of a large dinner plate. When it is made it is poured into a mold where it hardens in the form of a disk or slab generally a foot or more in diameter, and later gets broken into smaller pieces during transportation. These chunks of enamel may be readily broken up by a hammer, and if they are first wrapped in a piece of cloth the small particles will not fly about and get into one’s eye, and no enamel will be lost. When the enamel has been broken up so that none of the pieces are larger than a pea, it should be washed in clean water to free it from any dirt that it naturally contained or that it received from the cloth in which it was wrapped during the hammering process. Cleanliness cannot be too much emphasized, for the slightest particle of dirt mixed in with the enamel may often completely spoil a piece of work. Enamel if heated quite hot and then plunged into cold water will become so brittle that it can be broken up by the hands, but when treated in this manner is said to be harder to grind. Fig. 2. Grinding with Weighted Pestle. After the enamel has been broken up into small pieces it should be put in an agate or porcelain mortar and ground to a fine powder. This will take from twenty to twenty-five minutes of steady grinding, the length of time depending on the quality and quantity of the enamel, the strength used, etc. Water may or may not be mixed with the enamel during the grinding process, as the grinder prefers. If water is added the process may take a little longer but a very disagreeable noise is eliminated and the work may perhaps be slightly easier. Agate mortars are cleaner and so better than porcelain ones but are so much more expensive that they cannot be used for grinding large amounts. For this grinding machines or weighted pestles, such as Cunynghame describes in his “Art Enameling upon Metals,” should be used. The enamel should be ground until it is about the size of fine sand, and soft, not gritty, when rubbed gently between one’s thumb and forefinger. It should now be rinsed in clean (the purer the better) running water, the enamel being thoroughly stirred up and washed, the fine particles, “dregs” or “slimes” as they are called, being allowed to flow away. Often from ten to thirty per cent of the enamel is lost in this process. The remaining wet enamel powder is ready to be used. It may be kept for weeks under water in a glass jar or druggist’s salve box, but in time is said to deteriorate. If the enamel is to be used immediately it may be placed upon a clean copper or china palette which will be found very serviceable. It should be kept constantly wet and if possible under water. If, however, it becomes dry, it may be washed as described above and will probably be found in good condition; if not a slight grinding may assist matters. If enamel is not ground fine enough it is apt to have pit-holes in it when fired, and if it is not absolutely clean it is likely to have both pit-holes and black spots in it. Sometimes enamel is washed in nitric acid as well as water but this is generally not necessary. It is very important, however, to use water that contains very little iron, for iron will cause black spots in the enamel. If enamel is to be kept for any length of time it should be kept either as chunks preferably or as coarsely ground powder. When coarsely ground it may be kept dry in a dirt-proof jar or bottle. The “dregs” and “slimes” if washed clean may be kept and used for paints in painting on enamel. When enamel is bought in the form of a powder it is generally necessary to grind it finer and wash it thoroughly. 1 2 5 6 7