He tries to process the front edges of the shadow to get a natural look from light to dark. After he has set up this variation, Bruce then adds a little more matt crescent-shaped substance to form deeper shadows under the back of the head, as in the last two photos on the left. It also adds deeper shadows to the lower cheek area as in the upper right photo. He will return and treat these areas with his scrubs until he gets the tonal qualities in the shadows he is trying to achieve. When he finishes changing the shadows, Bruce puts the glass on a hot plate to dry. When it dries, it will cut a second matt layer to remove excess pigment, using dry sticks, cotton swabs, and scrubs as before. In the second photo on the right, he uses a dry stick to trim the image. With this image done, he signs it and launches it into the furnace up to 1235 * F as in the photo on the right in the center. The finished image can be seen in the lower right image. This image can be built into the pendant by fusing additional layers of glass on it, both above and below it. Warn about heat control: brown colors lose most of their color if you burn out at too high a temperature. Use only the minimum temperatures to secure the fuse by spending time on the temperature.
Melting.
Bruce makes his beads during the fusion process, where glass stacks, such as the left, heat up and turn into fused objects, such as the one on the right. This is one of the beads of Bruce's Scarab that he will showcase in this brochure. When used, the parts are placed on a ceramic shelf covered with a separator compound called a furnace wash. This prevents the glass from sticking to the shelf, but some things often stick to the glass and need to be ground. The shelf is then placed in a furnace and fired. Changes in the temperature inside the furnace for a typical melting run are shown below. The total firing cycle can be divided into three phases - heating, process, and cooling. The heating phase is when the temperature rises from room temperature to the temperature at which the process takes place. How quickly you raise the temperature during this phase depends mainly on how large the pieces are. The bigger the pieces, the slower you have to go to keep them from blowing apart from the differential heat, a phenomenon commonly referred to as thermal shock. This is more often the case at low temperatures when the atoms inside the glass are harder. The heating rate can be increased at higher temperatures.1600 - melting or process heating phase 1200 - 800 - annealed cooling phase. The processor fusion phase - anywhere there is always a process or fusion phase. This can be the maturation of glass paints or the fusion of glass pieces. Each time process has its own specific temperature and duration. Many times this phase can be slightly modified by replacing the extra time for lower temperature operation. Bruce uses this with a great advantage when it slows down melting, trying to allow air to flow between the layers of glass. Typical melting temperatures for use with the glass used by Bruce (apple) are 1350 * F for fixing, 1450 * F for full melting and 1550 ° F for flat melting. The difference between the two is the amount of glass flow that occurs - practically no glass flow when fastened to the shelf with a flat melt adhesion. Holding time in the furnace at process temperature depends to a great extent on the quantity of glass and on the speed of furnace heating. The cooling phase is the last part of the firing cycle and is often the most important phase in the finished product. The first part of this phase includes emergency cooling up to 1000 * F by ventilation of the kiln. If this is not done, unsightly crystals can form and grow on the glass surface, a condition known as derivation. It may take several cycles of opening and closing the oven door to make it settle at this temperature. The next part of this phase, part of slow cooling or annealing, is designed to minimize the stress and deformation trapped in the glass. This is the temperature range in which the chains of atoms in the glass can still move. If the temperature in this region drops too fast, the outer surface freezes, and the inner part still wants to shrink and move, trying to relieve the stress.
This is important because the voltage captured can lead to a breakdown of the part at a later stage. The lowest temperature at which glass ceases to move for reasonable periods of time is called the deformation point. Below this temperature stress, glass can no longer be melted and the cooling rate can be increased until it reaches the heatstroke point of the glass. The extent to which the temperature can be reduced during the cooling phase depends on the thickness of the glass. Developing the details of your firing schedule will require experimentation to recognize your furnace. Different parents react differently and cannot change the temperature so quickly. Many factors can affect your success. More information about melting can be found in the section "More than you ever wanted to know about beading".