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Post by jfox on Jan 9, 2019 11:18:27 GMT -6
Thanks for the treatise kinda came to those conclusions myself the hard way . cant find any evidence about the sublimation of KNaO. got any?
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Post by evan cornish-keefe on Jan 15, 2019 21:37:19 GMT -6
Hey Tom, Some of what you said is beyond me, and I'll do more research, but based on what I have seen and read multiple points of your statements don't make sense to me. "In that process, sodium undergoes thermal decomposition which renders it neutral." What does this mean, neutral in that it no longer acts as a flux? or that only from an unfritted source will become part of the crystal structure? or leaves the glaze as a gas? Sorry, i just don't follow. I use Lithium at cone 6 primarily because it's such an easy addition, as Lithium Carbonate doesn't bring other elements into the glaze, I consider it a slightly stronger flux than Sodium and certainly influences color response, i haven't noticed much effect on crystal structure, and I'm considering replacing it from my glazes because of it's solubility. Here's a link I found interesting: digitalfire.com/4sight/education/the_chemistry_physics_and_manufacturing_of_glaze_frits_340.html
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Post by tileman2 on Jan 17, 2019 6:20:34 GMT -6
Evan:
Google "Paulings Rules". Rule #4 is ionic Crystals." he also talks about electrostatic charges. All I was saying was: lithium, zinc, and silica all have hexagonal crystal lattices, with electrostatic ionic charges that attract each other. Sodium has a cubic crystal lattice , with an ionic charge high enough to interfere with the other three. Gordon's avatar is a sodium crystal. By "neutral" I meant sodium reaches a point where its charge is no longer high enough to interfere. At 2190F: sodium/potassium is no longer visible in X-Ray diffraction.
I read Tony's piece you referenced: he is just referencing long known and studied amphorous glass structures.
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Post by evan cornish-keefe on Feb 11, 2019 0:47:42 GMT -6
Hey Tom, If the charge of Sodium lowers in charge at high temperatures, does that remain true as temperature lowers again? And the fired glaze wouldn't show those fluxes under Xray diffraction? I'm curious to see sodium crystals in a glaze. And didn't realize Gordon's photo was of sodium. Would be cool to see examples of way sodium-lithium effects the glaze, do you have tests demonstrating that?
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