GLAZE-BASE (j) Drying
The drying procedure of the glaze-base and the drying time of a glaze-base depend on the temperature and humidity of where you are working, the type of glaze-base, its thickness and how absorbent the bisque is. There are four drying stages:
a. Dry enough to move.
b. Dry enough to clean:
c. Dry enough to decorate.
d. Too dry to decorate.
a. Dry enough to move: A few seconds after applying the glaze-base to the tile, you will see, looking at it from the side, that it has a brilliant, damp texture which, in seconds, shrinks as it dries. When this texture disappears, the piece is dry enough to be moved. You can lift it, touching only the back or sides, which will have to be cleaned and move it to a shelf to continue drying. If you do not want to waste time waiting for it to dry, put three or four bars of wood on the left side of your basin. As soon as you have poured the glaze-base over the tiles, while still shiny and drying, move them onto these wooden bars. While you have been working the glaze-base has collected round the wooden frame the tiles are balanced on. which can cause them to stick slightly, so when lifting them, hold them at two opposite corners and slightly turn each tile so it separates without tilting it. Having the bars on the table at the side of the container allows you to keep the tiles at the same level and not tilt them, so the glaze-base does not run and become uneven when being moved. Continue preparing tiles until the bars are full. By then, the first ones prepared will be dry enough to move onto the shelves. When moving them always use the top shelf first as, when you slip them onto the shelves, the glaze on their backs can be scratched off and fall, damaging anything that is underneath.
b. Dry enough to clean: After an hour, the tiles should be dry enough to be stacked for cleaning, face to face, glaze to glaze, without being damaged. Put them into groups of six to ten pairs. The drying time depends on the temperature and humidity of where you work and the type of bisque the tiles are made of and can take up to twelve hours. The more industrially made the worse they are and the longer they take to dry.
c. Dry enough to decorate: The glaze-base must be dry before you can begin decorating. This could take up to twenty-four hours. It has to be dry enough so as not to be pulled off by the dampness of your paintbrush. Dampness can also cause the colors to spread. You cannot see this happening, but, when fired, it can make the sharp outlines of your work look thicker and blurred, and the colors appear softer. If you want the tiles to dry more quickly after you have cleaned off the glaze-base, put them into a tile-stand, or lay them out where they are going to be decorated. Keeping the tiles together in piles helps to retain the humidity. In an emergency, put them in the kiln on low heat for a short while. Remember, it is easier to clean them when they are damp, but they should be dry for painting.
d. Too dry to decorate: When left for a long time, the glaze-base on your tiles can be so dry that, when painting, it will transfer to the brush like dust. To correct this problem, wet the glaze-base by lightly sprinkling it with clean water. Leave it for a while so the water spreads out evenly.
Alternatively, hold the tile horizontally, with the glaze-base facing down, and lower it into a basin of clean water. The tile should just touch the water, for a second, so that the front is damp and the back is still dry.
