Q: What should my VM13 Opaque look like after firing?
A: VM13 Opaque should not have a dull eggshell look to it. On the contrary, fired VM13 Opaque should exhibit a textured medium shine/gloss to the surface. This can be achieved by raising the opaque firing temperature by 10-20∞C higher than the recommended 890∞C.
Q: I have increased my VM13 opaque firing temperature by 10-20∞C, and my opaque is still coming out with a dull and flat appearance. What can I do?
A: Calibrate your furnace with a silver strip test.
Q: How can I calibrate my porcelain furnace without a silver strip test?
A: Make a porcelain tab of VM13 WIN (Window) at 0.5mm thickness and fire it at 900∞C. What you are looking for is a clear, non-cloudy tab that you can read fine print through. Once you achieve the desired appearance, then you know you have found the correct dentine firing temperature. Then add an additional 10-20∞C to find the best opaque firing temperature.
Q: I have calibrated my furnace and my opaque still comes out underfired and dull.
A: Make sure that you are using a honeycomb tray with platinum pins. A ceramic tray will act as a heat sink and can deprive the ceramic of approximately 20∞C. Also, it is better NOT to use firing pegs that have ceramic bases; they will also act as a heat sink.
Q: My VM13 shades are coming out too chromatic.
A: Do not put a heavy coat of VM13 Wash Opaque on the framework. When you apply the Wash Opaque, you are NOT trying to mask out the framework. You are enhancing a bond between the metal and the opaque.
Q: My VM13 is turning green after I fire it.
A: The silver content in the alloy you are using is too high. Vita recommends alloys with 20% or less silver content. If possible, it is best to use a silver-free alloy.
Q: I want to continue with the alloy that I am presently using, but it does contain silver. What can I do?
A: Use an anti-greening liquid with VM13. This will help prevent the silver oxides from contaminating the porcelain.
Q: When I was grinding on the restoration, the porcelain delaminated all the way to the exposed framework.
A: The opaque layer may be too thick. The VM13 Opaque is designed to mask out the framework with thin layers. DO NOT make your wash opaque (WO) too thick. The 2nd Opaque is the layer that is intended to mask the framework.
Q: Why isnít the 2nd bake fusing with the 1st bake?
A: Make sure that you are using VM13 on both bakes. This is also an indicator that the temperature may be too low.