TortoiseAvenger Posted July 6, 2014 Report Share Posted July 6, 2014 My recipe calls for "silica". My supplier stocks "Amorphous Silica." Do you think the two are interchangeable? Link to comment Share on other sites More sharing options...
Wyndham Posted July 7, 2014 Report Share Posted July 7, 2014 Silica comes in different fineness or mesh. 200, 325, 400 mesh. most potters use either 200 or 325. I was given some Amorphous Silica once but did not notice any difference, though others say it will melt earlier and change the look of a glaze. Amorphous Silica I believe cost more than 200 mesh. try some and see what you think. Wyndham Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted July 7, 2014 Report Share Posted July 7, 2014 So have they melted the silica into glass then reground? Link to comment Share on other sites More sharing options...
PeterH Posted July 7, 2014 Report Share Posted July 7, 2014 You might want to check if your supplier lists flint or quartz. I've never bought "silica" in the UK other than as flint or quartz. Quoting from Digitalfire http://digitalfire.com/4sight/material/flint_316.html The terms flint, quartz and silica have come to be used interchangeably in ceramics and you will see them all employed in recipes Regards, Peter Link to comment Share on other sites More sharing options...
oldlady Posted July 7, 2014 Report Share Posted July 7, 2014 my vote is for silica 325 because i have seen it specified in some of my favorite glaze recipes. i thought amorphous simply means that if not stored tightly in a sealed container it will absorb moisture from humidity in the air. how that would affect anything is ????? edited at 11:54 pm. duh!!!!!!!!!!!! i was thinking of the word anhydrous. i will now go stand in the corner. Link to comment Share on other sites More sharing options...
TortoiseAvenger Posted July 7, 2014 Author Report Share Posted July 7, 2014 In my world, a water absorbing substance is called hygroscopic. It matters when weighing things out because the more water something absorbs, the heavier it becomes. Thus, 100 g of a hygroscopic substance might only be 95 g of that substance, if the other 5 is water. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted July 8, 2014 Report Share Posted July 8, 2014 Amorphous silica is a very fine particle size. Chemically.... same source of SiO2. Because of the intimacy of the mix with smaller particles in a glaze coating, it CAN cause a differenece in the melting of a recipe calling for larger mesh sizes. Same way ball milling a glaze can change how it melts. It is WAY more hazardous to weigh out dry... becasue of the particle size and dusting. best, .......................john Link to comment Share on other sites More sharing options...
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