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Post by zachjmoore on Aug 27, 2018 15:57:09 GMT -6
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paul
Junior Member
Posts: 51
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Post by paul on Aug 27, 2018 16:19:21 GMT -6
Nice Ones !  |
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Post by tileman2 on Aug 27, 2018 20:13:26 GMT -6
Good work Zach. I noticed the lack of spike/ needle randoms. Which means you ditched the sodium.
Tom
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Post by hughey on Sept 1, 2018 2:27:14 GMT -6
Beautiful work. Looks like you have found some great glaze recipes.
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Post by walterwhite on Sept 7, 2018 13:34:22 GMT -6
Could we trouble you for recipes? Beautiful results
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Post by zachjmoore on Sept 26, 2018 13:21:17 GMT -6
Good work Zach. I noticed the lack of spike/ needle randoms. Which means you ditched the sodium. Tom Hey Tom, There is actually still a good bit of sodium in these glazes. I took a look at the formulas and all of them have around a 7% total amount of Na2O. Although, I don't know what a normal high/low amount is. |
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Post by zachjmoore on Sept 26, 2018 13:23:33 GMT -6
Could we trouble you for recipes? Beautiful results I'm going to keep some of them to myself while I continue to develop and use them for my own work, but I'd still be willing to share some! Which ones are you looking at? |
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Post by walterwhite on Dec 29, 2018 14:45:06 GMT -6
Could we trouble you for recipes? Beautiful results I'm going to keep some of them to myself while I continue to develop and use them for my own work, but I'd still be willing to share some! Which ones are you looking at? I was hoping for the recipes to 2,4,5, and 6 |
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Post by tileman2 on Dec 29, 2018 18:11:36 GMT -6
Good work Zach. I noticed the lack of spike/ needle randoms. Which means you ditched the sodium. Tom Hey Tom, There is actually still a good bit of sodium in these glazes. I took a look at the formulas and all of them have around a 7% total amount of Na2O. Although, I don't know what a normal high/low amount is. Zach: most of the 7% is coming from the frit. Frit is processed at temperatures above our firing range. In that process, sodium undergoes thermal decomposition which renders it neutral. It is the sodium that comes from glaze additions that react. |
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Post by evan cornish-keefe on Jan 3, 2019 20:13:14 GMT -6
Hey Tom, There is actually still a good bit of sodium in these glazes. I took a look at the formulas and all of them have around a 7% total amount of Na2O. Although, I don't know what a normal high/low amount is. Zach: most of the 7% is coming from the frit. Frit is processed at temperatures above our firing range. In that process, sodium undergoes thermal decomposition which renders it neutral. It is the sodium that comes from glaze additions that react. Hey Tom, I'm curious why you think sodium is responsible for that type of crystal formation? Is that your own observation, I've never noticed any correlation so wonder it that's just anecdotal, would be interested to learn more. Thanks |
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Post by tileman2 on Jan 4, 2019 6:22:01 GMT -6
Evan:
Will condense the answer as much as possible.
Lithium, silica, and zinc all have hexagonal crystal lattices. A lattice is the molecular chain that holds the atoms in an arranged order. When you fire to cone 6; you break this chain apart: called thermal disassociation. Potters call it an eutectic melt. Sodium has a cubic crystal lattice, but it also has a much stronger isoelectric point ( fancy word for stronger molecular magnet) Crystals are a hexagonal closed pack (HCP) arrangement of atoms, so upon soaking zinc and silica form their original hexagonal lattice. If sodium is present ( cubic crystal) with higher isoelectric point: it will distort the hexagonal lattice, or form spikes which are cubic crystals.
At cone 10 and up, sodium thermally decomposes: which is different from disassociation. Thermal decomposition means the atom have lost their molecular charge (cations) which means they cannot reform or attract other elements into a crystal lattice. If you ever noticed, you see differences in cone 6 and cone 10 crystal formations. Lithium is used at cone 6 because it has the weakest isoelectric point; meaning it does not have any influence over the crystal arrangement.
If you want to study: research crystal lattice, hexagonal closed pack, thermal disassociation, thermal decomposition, and isoelectric points. You might find reduction potential interesting as well.
Sodium comes from many places: the alumina hydrate often used has up to 10% sodium content. Some brands of silica, as well as some zinc ( mostly yellow).
Tom
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Post by jfox on Jan 8, 2019 8:13:56 GMT -6
Tom what do yo mean sodium thermally decomposes?what would it turn into?thermal decomposition applies to compounds, for instance sodium carbonate would evolve Carbon dioxide and sodium oxide would remain and form ionic liquid you would have to heat it to a gaseous state before it would decompose.some compounds can exist as gases the rest decompose. In a liquid melt like our glaze sodium would look for more stable partners like silicate and aluminates. interestingly the highest known temperature of thermal decomposition is carbon monoxide at over 7000 degrees F en.wikipedia.org/wiki/Thermal_decompositionen.wikipedia.org/wiki/Ionic_liquid |
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Post by tileman2 on Jan 8, 2019 19:23:01 GMT -6
Jim:
The University of Illinois -Champaign- did an extensive feldspars study using X-ray defraction and atomic microscopes. At 2190F sodium/ potassium was depleted and only anions were detectable. Ougland and Brindley did a study for the British Ceramic Society "Quanitive Study of the effects of high temperatures on silica, kaolin, and feldspar." Same conclusions. As you already know that the phase change of KnaO is from solid to gas.
Itching for a chemistry food fight are ya? It has been awhile.
Tom
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Post by jfox on Jan 8, 2019 20:08:31 GMT -6
too tired to fight but do like to see some references for some of your "theories"
on another area of clay research starting this week my daughter is essentially in command of the curiosity Rover on mars
the rover has arrived at an area that she has been analyzing clay minerals spectrographiclly from satellites orbiting mars over the next year she gets to choose what areas to sample and analyze. Over the past few years her and her associates at cal tech have been building a reference library of clay mineral signatures both natural and some they synthasysed created by instruments identical to those on the rover.
Im suprised that KNaO sublimates so readily as the boiling point of NaO is 3500 F
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Post by tileman2 on Jan 8, 2019 21:24:11 GMT -6
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