Debbie's bowl was one of those projects...
I have attempted the bowl three times all together. Each time the first fuse ended up the same, despite my best attempts at the desired result. The previous two times I attempted to slump the bowl, the glass cracked due to thermal shock, no matter how slowly I ramped up the kiln.... The third attempt was successful.... Lesson to me, let the piece be what it wants to be. Don't force it.
DEBBIE'S BOWL
The first step in creating any plate or bowl is to choose the design and then the materials and tools you wish to use.
Since our bowl was an attempt at a randomly layered piece, I choose to work in 90 COE glass by Spectrum.
Tools used for this project are the cutting pen, running shears, nip pliers and a mosaic cutters.
The second step is to cut your base piece. This is the piece that you will fuse the other pieces of glass onto. I turned the bowl mold upside down and traced the outline onto paper.
Once I have the circle traced, I cut it out and glue it to the piece of clear glass. This actually provides me with an accurate template to score around with the glass pen. Once the base piece is cut out, I then have to grind the edges to eliminate any sharp or jagged points... The base piece is then cleaned under warm water.
The third step is to cut up the smaller pieces of colored glass... In this project I used three types of iridized thin glass... Purple, pink and a clear.... I use the mosaic cutters to come up with random sized pieces.
Step four is probably the easiest step.... You simply place the colored pieces of glass onto the circular base piece, stacking them randomly until you have about two or three layers.... When fired flat, this should, in theory, produce an effect that resembles ice....
Step Five is fusing the pieces together in the first firing.... You can call this a flat fuse... The attempt was to fuse the piece to a point where it doesn't fuse fully flat, but rather in a state where colored pieces would melt into a mounded state looking like ice.... This means ramping the kiln to around 1300 - 1400 degrees F... Because this is not an exact science you must check on the piece every 15 - 20 minutes... Some how I missed the critical point and ended up with a fully fused piece...
Step Six is preparing the mold. Most molds used for glass sagging or slumping are composed of unfinished greenware.. This holds up to the extreme heat and can be used over and over again. Other mold types are made from copper, staineless steel and brass... Metal molds are generally used to SLUMP OVER ONLY... They tend to expand and contract and can damage or destroy a finished piece.... no matter what you use, you must first prepare the mold by coating it in at least three coats of Kiln wash.... Kiln wash is a product that prevents the glass from sticking permanently to your mold. It comes in a powdered form and must be mixed with water. It is applied with Haik brush to the mold....
Step Seven is sagging the flat fused piece into the mold.... For this step, the mold is placed into the kiln with the flat piece carefully positioned on top. Because the piece is now MUCH closer to the heating elements in the kiln a very slow ramp up is required... The kiln will be brought from the ambient temp to 500 degrees slowly. This reduces "thermal shock" which will crack the piece. Once the kiln hits 500 degrees, we can then ramp up to bring it to 1250 - 1300 F to soften the glass enough to let gravity take over and sag the bowl into the mold, thus taking it's shape. Once the piece is fully sagged, the kiln is turned down or off and the lid kept closed. This allows the piece to cool down slowly and stay at a constant temp throughout it's thickness. This is called annealing and removes stress from the piece so it won't crack or shatter over time.
The final piece....
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