|
Post by hughey on May 21, 2017 19:23:45 GMT -6
So I am patiently awaiting the arrival of my kiln and have been reading Fara Shimbo's Crystalline Glazes Understanding the Process and Materials and it is all making sense to me except for those damned charts with all of the colorants listed for her glaze recipes. The top of the chart has the headings RO/R2O, R2O3, and RO2 and then the colerants listed under those headings have decimal point numbers which in my mind don't relate to the percentage parts for the main glaze components. Sorry to be so dense, but I can't find an explanation in the book or on the web. Can anyone explain?
On the positive side, my partner and I got the garage cleaned out today and the electrician is coming tomorrow morning to run the electrical connection for the kiln. I also tried my hand at throwing a double walled vessel this morning and was moderately successful. I didn't keep the result, but at least I got a result... baby steps.
paul
|
|
|
Post by bill2015 on May 24, 2017 10:06:29 GMT -6
hughey, The RO/R2O, R2O3, RO2 refer to elements used in calculating the Unity formula of a glaze. The "R" is the symbol for any element. RO & R2O reference fluxes: Na2O and ZnO ( sodium and zinc) for example R2O3 references stabilizers or refractories: Al2O3 (alumina) for example RO2 references glass former: SiO2 (silica) for example
The colorants are likely writeen as less than 1 percent
|
|
Guru
New Member
Posts: 11
|
Post by Guru on May 25, 2017 6:36:51 GMT -6
Little bit of UMF (Unity Molecular Formula). The idea of UMF (by Hermann Seger) is that all oxides involved in glaze are represented by (interpolated) mol sum of all fluxes (Alkaline Earths & Alkali Metals) where mol sum of all fluxes is equal to 1. Sounds complicated but actually is easy to understand (https://www.youtube.com/watch?v=HyLjAg1_8_4&t=4s).
Today following oxides are commonly used in UMF ("R" is just a replacement for element in oxide):
SiO2 // Glass (RO2) Al2O3 // Intermediate (R2O3) B2O3 // Glass (R2O3) ___________
// Alkaline Earths (RO) MgO // Flux CaO // Flux SrO // Flux BaO // Flux
// Metallic oxide fluxes (RO) ZnO // Flux PbO // Flux
// Alkali Metals (R2O) Li2O // Flux Na2O // Flux K2O // Flux ___________
BeO // Other P2O5 // Glass TiO2 // Glass SnO2 // Opacifier ZrO // Opacifier ZrO2 // Opacifier
// Colorants V2O5 Cr2O3 MnO MnO2 FeO Fe2O3 CoO NiO CuO Cu2O CdO ...
// Other F
If it was anything unclear, feel free to ask. Cheers!
|
|
|
Post by hughey on May 26, 2017 19:12:59 GMT -6
Thanks for the explanations. I've gotten a few more books and am beginning to get my bearings.
Paul
|
|
fa
New Member
Posts: 21
|
Post by fa on Jun 6, 2017 10:09:05 GMT -6
All that stuff is somewhere on the Digitalfire.com website. Lots of recipes there.
|
|