I chose these technique, because it was the most adaptable to my projects,can be transformed, recycled and manufactured in a small space and it can also be interrupted when it’s necessary.
The piece can be made with crystals, stringers, confettis, dichroic glass, metal foils, colored and with several widths of glass following previous design.
Several fusions in different temperatures are made as part of the process after the chosen material.
Proper molds and Kilns with electronic components are chosen to schedule different temperatures and phases of the planned fusion.
Most of my color pieces are made with 100% compatible glass, crystals, and metals manufactured by Bullseye factory (Oregon, USA). When I work with the brasilian glass,I color my glass with proper glazes, and I can ‘t mix for fusing the two glasses, because of different composition and different COE (coefficient of expansion), it can be “stressed” and breake in the future.
COMPONENTS
Vitrifiers:
SILICON DIOXIDE - SILICON (sand 60% to 80%) - Fusion at 1780º C
ALUMINA
Fusion Material:
SODIUM OXIDE (to lower the fusion of glassy material to 750º C)
POTASSIUM CARBONATE (POTASH)
LEAD OXIDE
Stabilizers:
CALCIUM (ALKALI) (to increase hardness and become non soluble in water).
TYPES OF GLASSES
THE SODIUM-CALCIUM GLASS (Silicon + Sodium + Calcium)
Comprises most colorless and transparent glasses, the cheapest and the easiest to fuse.
THE LEAD GLASS or CRYSTAL (Silicon + Potassium + Lead)
The glass is denser, with a higher light refraction index, higher plasticity, which allows engraving and carving.
The optical glasses belong to this category. For photograph machine lenses, one should add lanthanium oxide and toner, for the dispersion of colored light.
BORON-SILICA GLASS (Silicon + Boron + Phosphorus)
The glasses are used in laboratories and for in the household (type PYREX) because they have a high resistance to thermal shock and a reduced dilation coefficient.
THE COLOR GLASSES
The color glasses are obtained through the addition of coloring agents (iron oxides, cobalt, magnesium, etc.)
The creation of glass does not depend only of those oxides, but of the composition of the glass mass and of the temperature being used.
As sand usually contains some oxides, we must remove them to produce colorless glass.
The production of color glasses depends on the knowledge of the technique and of the chemical added.
For example: Adding copper oxide, we produce blue and green glasses and raising the temperature, the ruby-colored glasses.
The OPAQUE GLASS and the TRANSLUCENT GLASS (similiar to alabaster) are also obtained from physico-chemical variations, which makes their manufacturing quite complex.
The IRIDISCENT GLASS (similar to dichroyc lamps, rainbows etc.) can be obtained adding salts dissolved in water over the glass in recooking or adding metallinc oxides to the mass during its fusion and reducing the temperature in their recooking.