Specifications

If it is not dry, the brush may pick up the glaze, rather than
put it down. If the glaze starts to shift or crawl while
painting, then more drying time is needed. Crawling can
also be caused by over fired bisque or bisque that has been
sitting around too long, collecting a greasy film. Do not
force faster drying with hair dryers; this can cause the glaze
to perform badly. If a quicker drying time is needed, use
indirect heat or a fan to dry the piece.
When possible, each successive coat of glaze should be
applied at a 45˚ angle to the previous coat to help prevent
streaking and unevenness. Do not be afraid of applying too
much glaze. The problems are more varied when glaze is
applied too heavily, but too thin an application is a much more
common error. Apply the number of coats recommended on
the jar or the technique that you may be following.
It is difficult to establish exactly what is meant by a "coat"
of glaze. The personal traits and work habits of an individual
vary the application. What does three coats mean in glaze
application? Usually a glaze requires three flowing coats for the
proper thickness in order for the glaze to perform to the desired
finish. Three coats could translate to four coats for someone
who is termed a light glazer. While some people may only
require two flowing coats to achieve the right deposit of glaze
onto the surface of the ware, some people will need more than
three coats of glaze. If glaze is applied according to the flowing
method just described, you should have the right amount for a
coat. A good rule to follow is to apply one coat and if there is
still bisque showing through the glaze, do not consider it the
first coat. When the bisque is fully covered in appearance then
that would be the first coat. The next two coats would fill the
requirements of the three coat term. The thickness of a post
card is about the recommended thickness for proper coverage
after 3 applications. You will learn through glazing pieces over
time whether you are a light or heavy glazer and will adjust the
application of glazes to fit your individual habits.
Clear glazes require two coats only, unless lusters or fired
metallics are used over them. Using more than two coats of
clear glaze on top of underglazes and one strokes can cause
the color to float up into the glaze. When two coats of clear
glaze have been applied and allowed to dry completely, it
should not be cold to the touch nor should you be able to see
through the glaze. If you cannot distinguish the colors under-
neath, then sufficient coverage has been made.
Occasionally you will run into problems when you are
glazing your ware. Hard spots in the bisque are areas that
resist glaze. Do not try to continually apply glaze to this area.
Flow one heavy coat on, letting it dry completely before
attempting to apply more glaze. With successive coats, glaze
the area with a fully loaded brush and a light touch. Each coat
must dry thoroughly or the previous coat will be lifted.
Application of glaze with a sponge is sometimes
beneficial, especially when a textured look is desired or when
an extra smooth application is necessary. For best results, use
a silk decorating sponge with spring to it. Synthetic or sea
wool sponges do not work well for all over glazing; they
produce a texture or a mottled look.
To apply glaze with a sponge, dampen the sponge and
remove the excess water with a paper towel. Pour the glaze
onto a tile, then dip the smoothest area of the sponge into the
glaze. Pat the glaze into place, overlapping slightly with each
pat. A light touch will apply glaze; a heavy touch will pick up
glaze. Pounce the sponge up and down in a straight motion.
Do not slide the sponge across the bisque surface as you
would a brush. Keep the sponge full. Before you reload the
sponge, look over what you have done to see if a heavy
deposit needs to be picked up and redistributed. Four to five
coats applied with a sponge is needed to achieve the three
brushed coats required for most glazes.
Textured looks are obtained by applying all the coats with
a sea wool sponge, allowing the glaze to dry thoroughly
between each coat. Non-flowing glazes will actually be
textured after firing. Flowing glazes will look pebbled, but
feel smooth to the touch.
Semi-transparent glazes tend to appear streaked and
uneven on very smooth pieces if all the glaze is applied with a
brush. If the glaze is applied entirely with a sponge, a pebbled
look will happen. The best way to achieve a perfect finish for
semi-transparent glazes is to alternate sponging and brushing
the coats to the surface. Apply four coats with this method.
Rolling A Glaze
For hard to reach spots inside containers, pouring or
rolling a glaze in the inside surface is a simple alternative to
glazing with a brush. The inside must be free of any debris
and clay dust. Any clay particles left inside the piece can
cause crawling problems. Excessive glaze in or on the
bottom of the piece can cause it to split, pit or crawl. These
problems can be overcome by making sure the excess glaze
is removed by inverting the piece as the glaze dries.
How to Roll:
•Choose a gloss glaze if possible. Smoother application is
easier and allows better cleaning of the fired surface.
•Thin the glaze to the consistency of light cream using
distilled water or Media. Mix enough glaze to completely
cover the area. More glaze is absorbed by the bisque
during this method due to the extra water. The glaze will
be thicker after rolling it into the inside due to absorption of
the bisque. Save all excess glaze and mark it accordingly.
•Dump the diluted glaze into the piece and rotate the piece
with a continuous motion, covering the entire inside
surface with glaze. Drain out the excess glaze and
continue to rotate the piece momentarily to avoid glaze
pile ups in any one place. Keep the piece inverted to dry.
This helps avoid the piece splitting during the firing and
avoids pitting of the glaze
•When the glaze is firm, turn the piece upright and check
for possible missed areas. Glaze these areas with a brush.
If a colored glaze was used, apply one or two light coats
with a brush to the top areas that may show. Wipe off any
glaze on the outside surface with a damp sponge.
•After the correction has been made, allow the piece to dry
before completing the rest of the glazing. You may notice
the dye from the glaze migrating to the outside of the
piece. There is no need for alarm as it fires away; the
glaze is not moving to the outside surface.
18
Glazes