Too many sources is what I had before and some conflicting, so a degree of confusion. Now I have so many of the bits and pieces put together and I have so much more clarity. Great to be on the school bench again. I will be seeing this a few times and taking notes.Thank you, great teaching.
I am so excited to find you and your Glaze Class series! I cannot afford $600, so thank you so very much for offering such valuable information for free!
Thank you so much for taking the time to do this, Mr Britt. It is very helpful and I'll definitely watch it over and over and copy all that in my notebook. Looking forward to part 2!
Thank you! I wish you came out with this a few years ago when I was still in school. I'm glad to see you back making videos and sharing some of your knowledge with us. Its extremely helpful.
You have clarified the Glaze Situation! We are working on Glaze Theory at college for a pottery class, and I knew there was something (a lot of something) missing from what they were trying to tell us! Thank you so much for taking the time to fill in the pits and valleys. Wonderful presentation!
Excellent excellent. Excellent this is absolutely wonderful and so generous of you to show us all of this I really really appreciate this. I am a chemist background and you explained it beautifully and I have so many Pottery questions. This is just wonderful. You did an excellent job. Thank you.!
I have 3-4 books that explain UMF and none did nearly as good a job as you, John! I was pretty baffled before, and my understanding increased so much, so quickly here. So thank you! I have questions: 1) Can you elaborate on "glass former" and what that means? I understand that a flux melts at the temperatures we fire to, and that a refractory material does not (and therefore helps stabilize/keep things from running) but the term "glass former"... could I think of this as the kind of "base" that the other two materials work from? What would happen, for example, if you put together a flux and a refractory material but you left out the "glass former"? 2) You mentioned that a frit is a manufactured, pre-fired glaze... is it then ground up and sold as a power? Is it defined as a glaze because it is composed of a flux/refractory/glass former, but primarily used as a flux when people are making their own glazes? Thanks a million, this was seriously so fantastic for someone who can't actually go to graduate school in ceramics but would really like to understand more about what they're doing.
Hello, here in Brazil we can´t find Gerstley borate anymore, can I use Gillespie borate instead? Thank you for your time, and for your classes. I really appreciat your book Mid-range glazes.
Yes Gillispie is a good sub...not the same but good now GB is gone. Bit more melts. Small amounts..it is great but some glazes have 50% so they run a bit.
The one thing that puzzles me having a small background in chemistry I know how to convert a carbonate to an oxide it's simply heat. If you take cobalt or copper carbonate put it in a glass beaker put it on a hot plate and keep it moving with a glass stir rod crank up the heat it'll turn into copper oxide so this happens at not too high of a temperature as a matter of fact I don't know the exact temperature I'd have to look it up but if we're putting a carbonate in a glaze and it goes onto a piece and then goes into a kiln doesn't it automatically turn into an oxide? I mean what benefit is there to using a carbonate over an oxide in this case?
Yes, you are right. But copper carbonate goes into the glaze easier, it is a fine powder.....sometimes copper oxide makes speckles. So depends on how they are processed. So another is zinc oxide...about 30 types...some very pure others with impurities. Some coarse. Some fine. So it makes a huge difference in your glazes.
@@johnbrittpottery you know I never even allowed my brain to go there how it actually physically incorporates with the glaze body now it makes sense to me. Thanks for clearing that up in my mind I've been pondering it for a long long time.
@@johnbrittpottery I think I'm going to ball mill some copper oxide and then do a microscopic comparison to see how fine I can get the copper oxide I'll post some pictures somewhere if I find anything interesting
I don’t understand any of this/: i’ve only ever used already mixed glazed at the studio i use. Is there any extremely dumbed down glaze info available? I don’t have ingredients to make my own. I just wanna learn how to glaze properly
If you first watch the ceramic materials workshop videos the video of John will make more sense. The cmw lectures on yt are more open to beginners , so a good background to better be able to understand this video. I am a beginner too.
this is so interesting i took Chem for nursing. so all this make sense. My question is. how do we know by a formula we are in the range of different firing cones. what numbers do i look at ? i understand the chemical part I need to know by number what are my ranges for them to be a cone ^6 7 etc.
You need the limits...(in the book in Overview section) for cone 6 (if I can remember) the alumina is between.0.2 and 0.5..and silica between 2.0 and 4.5...the boron is between 0.1 and 0.3. You can try googling cone 6 limits.
Hello John, is it possible to ad the temperatures in celcius. I´m from the Netherlands, and we don´t use fahrenheit here. And an other question . I have bought a new electric kiln. Is it useful to put extra cones inside for temperature control? Greetings Kees from Holland.
I'm from Argentina and we use Celsius too. Here's a conversion of some temperatures he mentioned: 3100 = 1704 ; 2350 = 1288 (^10); 2232 = 1222 (^6); 1878 = 1025 (^05); 1650 = 899 (Na melting point),
@@nedludd8633 Not to be contrary, but not everyone has new kilns and kilns are routinely 1 cone off from top to bottom. Witness cones are the best thing to keep your work consistent. Thermocouples are inaccurate and degrade with use so the temperature cannot be relied upon. Types S is the best but many have type K and they are old. The kilns fires based on thermocouple so I only trust witness cones not thermocouples! JMO!
Too many sources is what I had before and some conflicting, so a degree of confusion. Now I have so many of the bits and pieces put together and I have so much more clarity. Great to be on the school bench again. I will be seeing this a few times and taking notes.Thank you, great teaching.
I am so excited to find you and your Glaze Class series! I cannot afford $600, so thank you so very much for offering such valuable information for free!
That is exactly why I am doing it! More to come. Please do exercises or it is just cerebral.
Thank you so much for taking the time to do this, Mr Britt. It is very helpful and I'll definitely watch it over and over and copy all that in my notebook. Looking forward to part 2!
Tranks for the lecture. As a beginer that clarified lots of thinks on how the ceramics materials works, and now it can have more sense for me.
Thank you! I wish you came out with this a few years ago when I was still in school.
I'm glad to see you back making videos and sharing some of your knowledge with us. Its extremely helpful.
such great lesson, watching it over and over and it is getting more clear. You are awesome teacher, John
You have clarified the Glaze Situation! We are working on Glaze Theory at college for a pottery class, and I knew there was something (a lot of something) missing from what they were trying to tell us! Thank you so much for taking the time to fill in the pits and valleys. Wonderful presentation!
Glad to help. Gonna do one on Glazy soon...
Let me know if I forgot something or can clarify something.
Thanks John, Your explanation makes it easier to understand.
Amazing video. More clear and concise than what we got on my masters degree.
Best video on glazing chemistry I've found. Thanks so much!
Please have more!
So many book and here I am finally understanding what UMF actually is
Thank you for explaining this in a way I can understand!
Thank you soooo much! These videos are helping me learn so much.
Excellent excellent. Excellent this is absolutely wonderful and so generous of you to show us all of this I really really appreciate this. I am a chemist background and you explained it beautifully and I have so many Pottery questions. This is just wonderful. You did an excellent job. Thank you.!
Thx..I tried.
Excellent video John, thanks for taking the time to explain this, I finally get it :-)
Great vid. Can't wait for the sequel!
UMF, its better than nothing! Thanks Britt!
Thank you very much indeed. Looking forward to see your next demo.
Thanks so much for this video. Going to take me a long time to figure all this out!!! :)
Just superrrrr. Love and thanks from Turkey, Bodrum. So openly teaching🤭🤗👍
you are so great. Thank you so much
This is so clear and easy! Thank you!
Thanks for sharing your knowledge! :) Your video makes it very easy to follow.
Thank you so much! So well explained!
I have 3-4 books that explain UMF and none did nearly as good a job as you, John! I was pretty baffled before, and my understanding increased so much, so quickly here. So thank you! I have questions:
1) Can you elaborate on "glass former" and what that means? I understand that a flux melts at the temperatures we fire to, and that a refractory material does not (and therefore helps stabilize/keep things from running) but the term "glass former"... could I think of this as the kind of "base" that the other two materials work from? What would happen, for example, if you put together a flux and a refractory material but you left out the "glass former"?
2) You mentioned that a frit is a manufactured, pre-fired glaze... is it then ground up and sold as a power? Is it defined as a glaze because it is composed of a flux/refractory/glass former, but primarily used as a flux when people are making their own glazes?
Thanks a million, this was seriously so fantastic for someone who can't actually go to graduate school in ceramics but would really like to understand more about what they're doing.
Sorry didn't see this..Glass former is Silica and or Boron sometimes Phosphorous
Frit contains flux, refractory, and glass former but is dominated by flux ..so people can add kaolin and Silica to have a glaze at any temperature
Thank you John for sharing !
Thank you!!!!!! you are my new idol!!!!!!!
Great video, thank you so much for sharing!
Thank you!
Muchas Gracias!!! 👏👏👏
Thank you Soo much for this course
Thank you!!!!!
Thank you soo much...
Hello, here in Brazil we can´t find Gerstley borate anymore, can I use Gillespie borate instead? Thank you for your time, and for your classes. I really appreciat your book Mid-range glazes.
Yes Gillispie is a good sub...not the same but good now GB is gone. Bit more melts. Small amounts..it is great but some glazes have 50% so they run a bit.
@@johnbrittpottery Thank you very much ☺
The one thing that puzzles me having a small background in chemistry I know how to convert a carbonate to an oxide it's simply heat. If you take cobalt or copper carbonate put it in a glass beaker put it on a hot plate and keep it moving with a glass stir rod crank up the heat it'll turn into copper oxide so this happens at not too high of a temperature as a matter of fact I don't know the exact temperature I'd have to look it up but if we're putting a carbonate in a glaze and it goes onto a piece and then goes into a kiln doesn't it automatically turn into an oxide? I mean what benefit is there to using a carbonate over an oxide in this case?
Yes, you are right. But copper carbonate goes into the glaze easier, it is a fine powder.....sometimes copper oxide makes speckles. So depends on how they are processed. So another is zinc oxide...about 30 types...some very pure others with impurities. Some coarse. Some fine. So it makes a huge difference in your glazes.
@@johnbrittpottery you know I never even allowed my brain to go there how it actually physically incorporates with the glaze body now it makes sense to me. Thanks for clearing that up in my mind I've been pondering it for a long long time.
@@johnbrittpottery I think I'm going to ball mill some copper oxide and then do a microscopic comparison to see how fine I can get the copper oxide I'll post some pictures somewhere if I find anything interesting
I don’t understand any of this/: i’ve only ever used already mixed glazed at the studio i use. Is there any extremely dumbed down glaze info available? I don’t have ingredients to make my own. I just wanna learn how to glaze properly
Tons of stuff...free on Facebook, Ceramics Arts Daily...I gave DVD on my site , etc.
If you first watch the ceramic materials workshop videos the video of John will make more sense. The cmw lectures on yt are more open to beginners , so a good background to better be able to understand this video. I am a beginner too.
@@johnbrittpotteryHi John, nice lecture. Edouard Bastarache
@@edouardbastarache7045 Nice to hear from you Edouard ! Long time. Hope you are well in Quebec!?
😮😮😮😮
this is so interesting i took Chem for nursing. so all this make sense. My question is. how do we know by a formula we are in the range of different firing cones. what numbers do i look at ? i understand the chemical part I need to know by number what are my ranges for them to be a cone ^6 7 etc.
You need the limits...(in the book in Overview section) for cone 6 (if I can remember) the alumina is between.0.2 and 0.5..and silica between 2.0 and 4.5...the boron is between 0.1 and 0.3. You can try googling cone 6 limits.
I have another video describing this...think it is called Understanding Stull...
Here is another....go down to numbers...digitalfire.com/glossary/limit+formula
Why do they are have O’s next to them it means oxide right but what if your using an non oxide were would that go
For example the best one I can think of is silicon carbide
Which chemical formula is sic
Sodium carbonate is heated and the carbon dioxide goes off as a gas to yield sodium oxide.
@@farmlife4533 silicon carbide is heard. Burns off the carbon and yields silica
Does this mean the H20 is a Flux, or does that one not count?
No, water evaporates...it doesn't count
@@johnbrittpottery Yeah, that makes sense. Probably should have caught that one myself.. Thanks!
Hello John, is it possible to ad the temperatures in celcius. I´m from the Netherlands, and we don´t use fahrenheit here. And an other question . I have bought a new electric kiln. Is it useful to put extra cones inside for temperature control? Greetings Kees from Holland.
I'm from Argentina and we use Celsius too. Here's a conversion of some temperatures he mentioned: 3100 = 1704 ; 2350 = 1288 (^10); 2232 = 1222 (^6); 1878 = 1025 (^05); 1650 = 899 (Na melting point),
@@Neldidellavittoria Thank you.
If you look in my book I have a cone chart with both. Sorry I didn't do that but forgot.
Hi Kees Electric kilns are very even in temperature and controllers are very accurate now so there is no point in putting in extra cones .
@@nedludd8633 Not to be contrary, but not everyone has new kilns and kilns are routinely 1 cone off from top to bottom. Witness cones are the best thing to keep your work consistent. Thermocouples are inaccurate and degrade with use so the temperature cannot be relied upon. Types S is the best but many have type K and they are old. The kilns fires based on thermocouple so I only trust witness cones not thermocouples! JMO!
oooh.. alchemy.