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 42
FINISH—PLIQUE-À-JOUR
CHAPTER VIII
ENAMEL PAINTING 50
CHAPTER IX
PHOTOGRAPHS ON ENAMEL 57
------------------------------------------------------------------------
LIST OF ILLUSTRATIONS
FIG. PAGE
1 AGATE MORTAR AND PESTLE x
2 GRINDING WITH WEIGHTED PESTLE 2
3 ENAMELER’S SPATULA WITH WOODEN 10
HANDLE
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
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
[Illustration:
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.
------------------------------------------------------------------------
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.
[Illustration:
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.
------------------------------------------------------------------------