QUARTZ GLASSBLOWING ANSWERS TO FREQUENT QUESTIONS

1. How pure is your Raw Material?

 Our standard raw material, which is GE 214 fused quartz tubing and rod (also GE 124 for solids parts) is 99.995% by weight pure SiO2. The specifics of this and other Momentive (formerly GE) products including a chart of trace element contaminates can be found at THIS LINK to their website.

Other raw materials from other manufacturers are available with similar levels of purity upon request.
2. What is Annealing and why is it necessary Annealing is a process of controlled heating and cooling to remove thermal stress from glass and metal products after they have been worked or welded. Basically it requires heating to 30-50 degrees Centigrade above the Stress Point temperature, holding there until the entire part stabilizes in core temperature, and then slowly cooling to below the Stress Point.

A thorough explanation of "The Annealing of Fused Quartz" as pertains to Momentive products can be found in a .pdf document linked here.
3. What are the melting / softening temperatures of quartz? (Thermal Properties) The Softening Point of our quartz is 1683 deg. C. At this point it will start to deform and "sag" under its own weight. The actual melting point (at which the glass would pool and drip) is not clearly defined for fused quartz as it is for "softer glasses." Instead, fused quartz simply becomes more and more soft and liquid as its temperature is raised over a broad range above the softening point.

This link on the Momentive website will give you more information about the thermal properties of fused quartz glass.

4. What are the Optical properties of quartz? This link on the Momentive website will give you more information about the Optical properties of fused quartz glass.

5. What are the Electrical properties of quartz? This link on the Momentive website will give you more information about the Electrical properties of fused quartz glass.

6. How does quartz glass React to various chemicals? This link on the Momentive website will give you more information about the Reactivity properties of fused quartz glass.

7. How much do various gasses Permeate through fused quartz? This link on the Momentive website will give you more information about the Gas Permeability properties of fused quartz glass.

8. How much pressure can I place within a quartz tube or behind a quartz plate before it is likely to rupture? This link on the Momentive website will give you more information about determination of the Pressure Holding limits of fused quartz glass.

9. What are the other Physical Properties of fused quartz products? This link on the Momentive website will give you more information about the Mechanical properties of fused quartz glass.