ENAMEL PAINTING
ENAMEL painting is usually done on a background of opaque white enamel,
although other opaque colors are sometimes used. The metal must be
prepared in the regular manner, and one or two coats of enamel charged
and fired, the last coat being fired to as perfect smoothness as
possible. Instead of flushing the enamel smooth it is often advisable to
stone and fire it, by which processes a smoother surface is obtained.
After this last firing, the black flakes of metallic oxide which will be
found on the metal should be brushed away, leaving the piece clean and
ready to be painted. It is desirable not to have too thick a layer of
enamel, as in that case it is apt to chip off in some of the later
firings. If, on the other hand, the enamel layer is thin, it is quite
difficult to get it smooth.
[Illustration:
FIG. 9. COPPER PICKLE PAN.
]
Any picture desired may now be painted on the enamel surface, either
with ordinary china paints or finely ground enamel “slimes” mixed with
oil of cloves or oil of lavender. This painting may be done with a small
camel’s-hair brush and when finished should be fired until the enamel
fuses. The piece should be allowed to cool slowly and when cool should
be charged with a coat or two of clear fondant which, after being fired,
may or may not be stoned and polished, as the artist sees fit. If the
painting requires it, it may be touched up and fired several times
before being charged with the fondant, but the fewer times a piece is
fired the less chance there is for accidents which may prove fatal to
the work of art.
If the metal used is very thin, it will be necessary to enamel it on the
back as well as on the front, for a thin piece of metal which is
enameled on one side only will warp out of shape, but if enameled on
both sides will keep its shape perfectly. Of course the enamel on the
back may be of any color and need not be finished carefully, as it is
there for use not ornament.
An enamel painting must be fired with great care. First it must be
warmed by degrees before put into the muffle, so that the oil may have a
chance to evaporate. It should then be placed partly in the muffle and
not put way in and should not be heated to a red heat until the residues
of the oils shall have burnt away. If too hot a muffle is used, or if
the piece is fired too long, the painting will appear blurred and faint.
If the painting appears blistered after firing, it is due to the fact
that the oils used contained too much carbonaceous residue.
The fondant used on an enamel painting should be very finely ground,
much more so than for ordinary work, and the first layer of fondant
should not be fired to smoothness but only until it just begins to flow,
as was the case with the painting itself. The last layer of fondant
should of course be fired as smooth as possible.
* * * * *
If a large number of pieces are to be painted with the same design,
there are a number of mechanical means that can be used to take the
place of free-hand painting. We will outline one of these processes,
which is as follows.
Etch a copper plate with the outline of the design that is to be painted
on the enamel. The etching on the copper plate must be a positive, not a
negative; that is, the design must appear on the plate as it is to
appear on the enamel and not reversed as in ordinary etching. The design
must also be exactly the same size as the one to appear on the enamel.
The lines in the etching should now be filled with finely ground enamel
paints mixed with oil of cloves or some such medium. It is best to use
paint of the color that is to predominate in the picture, although in
some cases it will be found that black will give the best working
outline.
When the lines of the etching are filled with the paint, the plate
should be scraped smooth so that no paint remains on it except in the
etched lines. The plate should now be pressed against a piece of thin,
smooth, sheet rubber, to which the paint will stick in preference to the
copper plate, thus transferring the design to the sheet of rubber, where
it appears reversed.
The rubber with the design side down is now pressed upon the smooth
surface of the white enamel, which should be prepared in the same way as
it would be prepared for regular painting. The design is thus
transferred from the rubber to the enamel surface, where it appears
again positive.
The enamel surface now has on it the outline of the design either in
black or in color as the case may be. From this point on, the process is
the same as in regular hand painting on enamel, but as the outline has
been blocked in, the work is considerably easier. A speed and uniformity
are obtained by this process which it is difficult to equal with
free-hand work.
Another process whereby a number of similar designs can be easily
executed is by decalcomania. Decalcomania pictures are made in Germany
and can be obtained through any artists’ supply house. In this case the
white enamel background is obtained in the usual manner, after which a
decalcomania picture is transferred to the enamel surface. The enamel is
first covered with a very thin layer of size or gum as in the case of
foils. When the size becomes sticky, the decalcomania picture should be
placed face downwards on the enamel. The paper on the back of the
picture should now be wet with a sponge until it becomes loose, when it
should be removed and the remaining scum washed off with plenty of clean
water. The piece after being dried thoroughly is ready to be fired. The
rest of the process is the same as in regular painted enamel work. Great
care must be taken in firing the decalcomania work.
------------------------------------------------------------------------