Understanding Pottery Chapter 9 Oxides, Washes, Underglazes and Stains
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- čas přidán 20. 05. 2020
- Welcome to Understanding Pottery, Chapter 9: Oxides, Washes, Underglazes and Stains. In this podcast you will learn why these surfaces treatments are different and how to best use them in your creative process. This is the third chapter in the section titled Use of Raw Materials.
The next topic in the series is Geology for Potters.
Understanding Pottery is a series in production by Washington Street Studios. The video series is a digital textbook that will take you through the entire ceramic process from the raw material through the finished ceramic pieces. There are five sections and twenty-six chapters planned in the series and they are:
Section I: The Pottery Making Sequence
Chapter 1: What is Clay?
Chapter 2: Clay Properties and Drying
Chapter 3: Bisque Firing
Chapter 4: Tips for Successful Glazing
Chapter 5: Pyrometric Cones
Chapter 6: Glaze Firing
Section II: Use of Raw Materials
Chapter 7: Chemistry for Potters
Chapter 8: Glaze Chemistry
Chapter 9: Oxides, Washes, Underglazes and Stains
Chapter 10: Geology for Potters
Chapter 11: Use of Local Materials
Section III: Kilns and Firings
Chapter 12: Atmospheric Firings
Chapter 13: Wood-Fired Kilns
Chapter 14: Gas-Fired Kilns
Chapter 15: Electric Kilns
Chapter 16: Raku Kilns
Section IV: Solving Problems
Chapter 17: Kiln Performance Problems
Chapter 18: Clay Body Defects
Chapter 19: Glaze Defects
Section V: Practical Applications
Chapter 20: Pottery Myths, Errors and Misconceptions
Chapter 21: Thixotropy, Quartz Inversions and Other Pottery Mysteries
Chapter 22: Pottery and Physics
Chapter 23: Pottery Figurin’ (Math)
Chapter 24: Personal Safety with Pottery
Chapter 25: Critiquing Your Own Pottery: Design Principles You Can Use
Chapter 26: Tips for Buying Used Pottery Equipment
Show notes can be found at www.hfclay.com/the-potters-ro...
The Potters’ Round Table is brought to you by Washington Street Studios, a community pottery studio, gallery, and pottery school located in Harpers Ferry / Bolivar, WV. We exist to provide ceramic artists an affordable, fully equipped studio space for aspiring, emerging and established artists to share their creative energy and knowledge in an environment designed to support the ceramic artist. If you want to learn more about Washington Street Studios, visit our website at www.hfclay.com/.
At Washington Street Studios, we believe the sharing of creative energy and knowledge will improve the quality of our art and increase the appreciation of art within our community. We are striving to create an environment where the arts are shared and appreciated. We want to grow as a family of artists and contribute to our community. This podcast is one of our steps to share our passion for the ceramic arts, creative energy and knowledge with other artists and art lovers.
We also created an audio version to expand our audience. If you are looking for the podcast of our show search for the ‘The Potters Round Table’ on your podcast platform of choice.
The ending is so adorable when he reread the board. I'm a huge fan of this series, Phil is an amazing teacher and is so knowledgeable. Thank you for your work!
I’m sorry to say Phil passed away in July of 2021. He did leave a great legacy in these videos!
This guy is such a natural teacher, and so generous with his vast knowledge and experience. Thank you very much for this.
I agree, Phil was a natural teacher, unfortunately we lost Phil in July of 2021. Fortunately we captured much of his knowledge and talent in these videos! I hope you enjoy them all.
@@WashingtonStreetStudios A great loss to your community, I'm sure.
Now that's what I call teaching! Crystal clear and most helpful.
Susan Williams, Thank you, Phil would have been pleased to see this comment! He left us a great legacy. Thank you for watching and commenting. I hope you enjoy all the videos and find them useful. If you do, please share the channel with your friends and fellow potters to help grow our community.
These are a great series of lectures, I would highly recommend to anyone who would like to increase their knowledge and understanding of pottery to watch them. Phil is a great teacher . Thanks for making these available for free. I’ve signed up to your basic patreon package as a sign of appreciation, thank you .
Thank you for your support mosseyw, we love being able to share this information with the community! Be sure to check out our livestream of 'An Introduction to Glaze Testing' on Saturday, 9/12 at 2PM eastern!
Whenever I come across one of your videos I always know I'm going to understand the topic thoroughly and all questions will be answered. Never disappoints! Thank you all so much!
Doug Rubenstein, Phil was a treasure, unfortunately he passed away last year. We will have his videos on this channel as long as there is a 'CZcams', so please enjoy! Hopefully our future videos will be as valuable.
What a ‘find’ this series of lectures is. I’ve been looking for an accessible explanatory course for ages. Clearly explained. Thank you
Thank you Wendy. Please share the channel with your friends and fellow potters to help us spread the word!
I have sent your lecture to all of our members at Potters Addict Ceramic Art Centre. Kelowna BC Canada, next week they start their basic glaze and decorating course so thank you very much. Phil. Bonnie Anderson EH!
Bonnie Anderson, Thank you very much for promoting the channel. I hope you all find the materials presented useful! Unfortunately Phil passed away in July and can't be a part of the celebration! I'm very happy that we captured much of his knowledge on this channel.
This was amazing! Thank you so much! I have struggled to understand the difference between oxide, stain, wash, etc. Every other site I checked talked about examples and assumed you already knew the most basics. I learned a lot watching this. Definitely subscribing and sharing.
Janet, thank you for the encouragement, normally I would say subscribe and share, but you got it!
Great information !😊❤
Thank you for the encouragement.
excellent well explained information
Pete Arnold, Thanks for the encouragement!
These shorts are so helpful..I wish I could be closer but I am clear across the u.s. from you and cant get there.. thankyou
The miracle of the internet makes us neighbors! Thanks for watching and please share the channel with your friends and fellow potters to help us grow our community.
Thank you for this lucid and somewhat comprehensive review in an organized and scientific manner. This will provide confidence and clarity for me in decorating my ceramics! I have liked and subscribed and will review your earlier presentations.
Corinne, Thank you for your encouragement! There are lots of videos and I hope you enjoy them all. Please share the channel with your friends and fellow potters.
Thank you thank you thank you!! Concise and clear, and so much info! So generous.
Thanks, I hope you enjoy all the videos
So lucid and well explained. If only all pottery teachers went through the terms - with examples - as meticulously. What a pleasures! Thank you 👏👏
Merle Huntley, thank you for your encouragement! Phil was a blessing to us all and a valuable resource for the ceramic community. Please share the channel with your friends and fellow potters to help us grow our community!
Watching this podcast now, just wonderful!!!
I hope you enjoy all the videos.
Great content. Thanks a lot
Thanks for the encouragement and keep watching
Great lecture, it helped me to learn about the english terms (i'm mexican) to name the different coatings, very useful to understand books about decoration techniques.
bcarrave, that's great news! I hope you enjoy and learn from all the videos on the channel. And please share the channel with your friends and fellow potters to help us grow our ceramics community!
I just restarted doing pottery after a twenty year hiatus. I recently bought some Mason stains but wasn't sure what to do with them and how they differed from oxides. Your lecture really clarified how I can use them. I especially appreciated the chart at the end. Thanks!
Dawn, it's great to know the video is helpful! Please share the channel with your friends and fellow potters to help us grow our community. And keep watching!
excellent, simple and with great clarity, thank you
Thank you for the encouragement and I hope you enjoy all the videos!
You are answering all of my questions. Thanks you.
Glad to help
It’s so very exciting to me to be able to find this channel. Your explanation is divine. I’m really looking forward to learning more.
This great grandma hasn’t played with clay since high school. I am having such fun.
Thank you so much!
We are very happy you have found us! Please share with your friends and fellow potters, and let us know how you are getting on with your pottery!
A well-informed presentation of what can be a very confusing topic. Keep up the good work.
Thanks Neil. There are lots of videos available, I hope you enjoy them.
awww thank you so much I am so impressed with this #9 exactly the info I was looking for, I am so grateful. love to you all. xx
Much more to come, tell your friends!
A great refresher course! Thank you!
This is our most popular video since starting the channel, we are surprised by it's popularity. Thank you for the encouragement!
Thank you so much!! You're such a joy as a teacher!!
Elizabeth, you're welcome, enjoy the channel and share it with your friends and fellow potters to help us grow our community.
Incredibly useful! Thank you so much for sharing ❤️
starcrossing, we are pleased that you find the content useful. Please share the channel with your friends and fellow potters to help us grow our community!
Great job answering questions I had. Thanks
Cindy, this episode is our most popular of all our videos! I also found it very useful and informative.
Amazing thank you!!!
Sally, we are really glad that you enjoyed the video! Please share our channel with your friends and fellow potters to help us grow our community! Check out Jenna's demonstration video for underglaze transfers as a follow-on to this video (czcams.com/video/19GGFF08ugY/video.html)
Great show and thank you for full description of how to use pottery materials. #Keepupthegreatwork
Thanks for the encouragement and please share the channel with your friends and fellow potters.
This information was very helpful. I learned a lot. Thank you.
I agree this lecture provided a lot of good information on surface decoration, something I don't know much about!
Remarkable man.. ❤
Yes he was!
Very educational and informative! Thanks!
Tracy, Thank you for the encouragement! Please share the channel with your friends and fellow potters to help us grow our community.
Of course I enjoyed the show, it was really great and I have just subscribed, thanks!
puchululina, that's great to hear! Please share the channel with your friends and fellow potters to help us grow the community!
Thank you! I took your clay course at Hood. You're a great teacher.
Joe, I've forwarded this comment to Phil. We all agree, Phil is a great teacher and the best resource we know for a scientific view of ceramics!
Wow, this was very helpful and informative for me and gives me a much better understanding. Thank you so much!!!
ICH, Thank you for the encouragement! We hope you enjoy all the videos!
I love this lesson ! Time to learn some chemistry :)
I agree Erman, this one taught me a lot and I was able to use it right away! Enjoy the chemistry, it's very good as well!
Wow SO helpful! Thank you for sharing your ceramics knowledge.
Claire MacDonell, thank you very much for watching our videos and we are happy you found it informative! Please share the channel with your friends and fellow potters to help us grow our ceramics community. I hope you enjoy all the videos.
This was so useful. Thank you so much!
MaZ, this is one of my favorite lectures. Mostly I'm a 'dip-glazer' and after this lecture I started using some underglazes. Really expanded my decoration techniques! Thanks for watching and keep sharing!
Thanks
Thanks Phil for putting all of this valuable information in one place and explaining it so well. I enjoin experimenting to get different results and your explanations have answered some questions I had about why I was getting some of my end results. Some more successful than others and some pleasantly surprising when the kiln door was opened. I have taken copious notes today and also jotted down new things to try with the materials I already have and what I still need to purchase. Wish me luck.
Best of luck and thank you for the support! It's great to know the information is useful and inspires experimentation!
Please share the channel with your friends and fellow potters to help us grow our community.
Great information here, And it supports what I already know about the topic. Thank you.
This is one of the most viewed videos we posted, and it is information that is really already known!
Thank you Phil!!
Phil gave us a great legacy in these videos before he passed, we have been blessed.
@@WashingtonStreetStudios May his creative soul rest in peace!
excellent explanation, thank you
Audrey, this is our most popular video this month! We're happy you enjoyed it. Please share it with your friends and fellow potters.
These videos are incredible thank you
Ri m, Thank you and please share the channel with your friends and fellow potters to help us grow our community.
@@WashingtonStreetStudios HA unfortunately I have neither that is why I've been looking so hard for something like what you've been creating! thank you!
Very informative, I am a potter in Tasmania and being self taught I found this very good as the terms used are complex. Great explanation. Am running a 100 cubic foot gas trolley kiln and use mainly stoneware bodies reduction fired. Thanks for the info, regards, John.
John, it's great that you find our channel useful, thank you for the feedback! Your kiln sounds awesome! Do you have a website? You are the first potter I know of from Tasmania!
Please share the channel with your friends and fellow potters to help us grow our community.
@@WashingtonStreetStudios hi , I haven't got a website as I am a little old fashioned and not very tech minded. My email is ridgebacktiger@gmail.com I had to stop potting a few years ago for family reasons and have moved my kiln to another site and am currently rebuilding my studio. I was a tree faller and was injured back in the eighties and was looking for another vocation and by chance discovered pottery. Someone I met helped me build a small wood fired kiln next was a 30 cubic foot downdraft wood fired kiln, next was a 4 burner 30 cubic foot gas kiln and when I left mainland Western Australia to live in Tasmania I brought a 100 cubic foot gas trolley kiln with me. I pretty much dived into pottery head first. By the time I had set up here in 1997 I had done a small business course and got a bulk gas tank hooked up and went for it. I didn't know how to pull a handle for a coffee cup properly and attach it but after a week I had learnt enough to get going. Well things can be hard when your learning but working up to 16 hour days 7 days a week my pottery became a reality. I did get some customers that took large orders every month, mainly cups, casseroles, bread crocks etc. My main clay body was Walkers pb103 from Victoria which was fine 120 mess stoneware body and I used a very heavily grogged sculpters clay for bigger pieces. I used a tonne of clay per month for a number of years. I absolutely love pottery. My studio is taking time to finish as the weather here is very unpredictable , am working on my pugmill bench at the moment and when the weather clears will concrete some more floor. Most of my work now is going to be mostly for charity raising, I would like to meet another potter to share the studio with me and will teach my grandkids as I'm on my own now. I will be checking out all your stuff from Washinton studios as you explain things really well , your a born teacher, thanks very much for your show. Ceramics is a vast field and you put things in perspective in a simple direct way, thanks again, regards,John Navarro.
John, what a great story, thank you for sharing! You make me want to visit Tasmania and check out your studio! If there is anything we can do to help or topics you would like covered, let us know!
Wow this is immensely helpful 🙏
Kate C, we are happy you find the videos helpful, tell your friends and fellow potters. And I hope you enjoy the entire series!
Thank you very much! This is very helpfull
This is one of my favorite videos, thanks for watching and please share with your friends and fellow potters.
Thanks, very informative
We’re happy you found the video useful, please share the channel with your friends and fellow potters to help grow our community!
More fun stuff from a talk by Phil.
I will be mixing some powdered pigment with Transparent Glaze and Terra Sigliatta and firing on test tiles in my wee kiln. Just to see what happens, expecting naught will mean I may be pleasantly surprised or not.
Cheers...Freddie
Sounds like fun!
Very great lecture, I love this sir. God bless you richly
We hope you find value in all the lectures! And God has blessed us very richly indeed!
Thanks so much for explaining the science and differences behind the different types of applications 💕
Happy that you found it helpful. Subscribe to our channel and you will be notified when more videos are available. There are 26 chapters planned for this series!
Thanks for great lectures and clarity, seflessly made available. There is one problem that I experience with underglazes (not covered here) and that is Shivering. It seems that the underglaze doesn't bond well to the pot but forms a stronger bond with the glaze and then peels off only where the underglaze is applied. Higher firing doesn't solve the problem.
Shivering is likely caused by a mis-matched shrinkage level between the glaze and underglaze. If the underglaze is low-fire or mid-fire and you fire it to a higher temperature, you can get shivering, and other nasty results. Phil could explain this better, but he passed last July. If you are looking for a replacement, I have made a slip from the claybody and colored it with mason stains. If you use the colored slip on greenware, it tends to stay on the pot better. Some of the color could disappear at high temps, but it's worth a shot if your underglaze is shivering.
Good luck!
@@WashingtonStreetStudios Thank you and so sorry about Phil. A Great loss.. It is low-fire and the underglaze peels off with the glaze leaving the white body exposed. Sorry, I should have said bisque-firing with underglaze at higher low-temp firing (1060C) doesn't solve the problem. I have tried at stoneware temps and don't have the problem but as Phil mentioned the colours are no longer bright and bleed slightly. As a last ditch approach I am trying other clay bodies - shrinkage must definitely be the culprit. Thanks again..
الجليز معادلة كيميائية السليكا فيها اساسها، اللون الأحمر اصعب جليز ويمكن التلوين بغير الألوان والفرن مخرجاته مفاجئة
I am very thankful for these wonderful lectures.Every thing is explained so clearly. would like to know how Terra sigillata turns out in electric kiln and also how much flux should be added to make an engobe.
I will forward this question to Phil and post his response. Really good question!
Hi,
Thanks for your comments and for your questions. Terra sigillata is generally used to provide a very fine-grained (fine textured) surface coating, typically for burnishing, or simply to change the surface coloration. It doesn't really matter how it is fired, except that at higher temperatures (above bIsque) the sheen of the coating may be lost, and the color will be affected by the kiln atmosphere (oxidation vs. reduction).
You can think of an engobe as something that is somewhere between a slip (plain clay) and a glaze, or think of an underfired glaze. Engobes generally do not get as “glassy” looking as glazes when fired, but they are also more dense/vitrified than just plain clay. There is no set amount of flux that is used in engobes, it depends upon how glassy you want the engobe to look; more flux makes it more like a glaze; less flux makes it more like a slip. So the amount also depends upon what temperature you are firing to.
Phil
@@WashingtonStreetStudios Thank you so much
thank you very much
You are welcome!
Great
Thank you for the encouragement!
I appreciate all the great and informative information you provided and continue to provide. The question I continue to ask is the effect and or colors from these techniques from Low Fire vs High fire clays. What can you add to this?
Gamer, I am not sure I understand the question, so please forgive me if this is not the answer you are looking for! And to be clear, Phil passed away last July, so I will try to answer based on the knowledge I gained working with Phil over the last decade.
Generally, the higher the temperature, the more muted the color of the clays become. Low fire clays tend to keep a lot of their color, for example terra cotta, which keeps most of the red color after being fired. Mid fire clays that are red or brown when they are in the raw state, will turn a darker brown, red or rusty color when they are fired to maturity at cone six. White mid fire clays will fire to white, grey or buff colors. And at high fire (cone 8 and above) the white clays will be much the same. Red and brown clays will have the colors mute to a light brown and many will produce spots, especially when they are fired in reduction. Similarly the colors in the oxides, and washes will be muted as well. Stains will often lose all their color, unless they are encapsulated to resist or survive the high temperature, and most stains labeled mid or high fire, are ecapsulated stains.
I hope this helps, let me know if you have specific questions!
Thank you for your in-depth tutorial. :-) Can an underglaze be applied on top of a glaze? And should a clear glaze be coated over the underglaze if it will to be used on kitchen wares?
XMa, Thanks for the questions!
Underglaze should not be used on top of a glaze. Once glaze is fired it no longer absorbs water, the underglaze will not adhere well. And yes, you should use a translucent glaze over underglaze. It does not have to be clear, and opaque glazes will render the underglaze invisible.
Thanks and keep watching.
@@WashingtonStreetStudios Noted. Many thanks!
Thank for this super explanation about differents effect of decoration ... Sorry for my bad English but it isn't my mother langage ...
Jean-Claude Godefroid, Thank you for the encouragement! Please share the channel to help us grow our community and we hope you enjoy all the content!
I'm interested in a food safe glaze for low temp wood firing. too bad ashes will not do it because i heat with wood, and could come up with an oil drum full of ashes any year.
Unfortunately our glaze expert and instructor for this series, Phil Berneburg, passed away last July. You could try glazey.org to try and find a recipe. I wish you luck, it's a pretty tall order!
Hi, you have the most informative video about ceramic stains in CZcams period! When I was looking at the chemical composition of mason stains, I noticed reds and yellows contained Zirconium Silicate to encapsulate CdSe and CdS because the company indicates both of these cadmium compounds are fugitive at high temps. I didn't see any trace of Zr or Si in the greens, blues and purples. Is this because CoO, Al2O3, Cr2O3 (and ZnO??) that make up blues and greens are stable, and less fugitive at high temps? Can you comment on this please?
Unfortunately Phil, the expert, passed away last year, but I did learn from Phil over the decade we were in business together. You are correct, the blues and greens are more stable at higher temperatures. And I like your terminology about compounds being fugitive at higher temperatures. Great use of language to use creative words and still be understood! Well done.
❤thx
You are most welcome!
this is an amazing lecture! i am starting to experiment with an iron oxide as a stain. if i put a clear glaze over it, should i do that before firing the piece with the oxide, or after? thank you for this video!!
noelle raffo, thank you for the encouragement and the good question. If your clay is raw, and you intend to bisque fire the piece, you can stain the piece raw, bique fire it, then apply clear glaze. If your piece is already bisque fired, or if you single fire, then you can apply the glaze right over the stain. You can also bisque fire, stain, bisque fire again, glaze and glaze fire, but that is really a waste of energy. A good friend of mine is a sculptor, and she will stain, or paint with underglaze multiple times and bisque fire multiple times as well, until she gets the result she is looking for. It's difficult to get it wrong to the point you can't fix it! Enjoy the experimentation and let us know how it works out.
im curious about making flux to add dimension to glazes--do you cover this topic in your classes? thanks for sharing !!
If you have a specific goal, please let us know and we'll respond as best we can. We are planning a Potters' Round Table on Ash Glazes., and ash is a powerful flux, in February 2021.
For now you can check out the following videos to learn more about fluxes:
czcams.com/video/E0liBYRYSEg/video.html What Glaze Recipes Can Tell You
czcams.com/video/bZRJAVwifwA/video.html An Introduction to Glaze Testing Part 1
czcams.com/video/PqQl8mN6nI0/video.html An Introduction to Glaze Testing Part 2
And for more in depth information:
czcams.com/video/fKJL4mRKfa8/video.html An Introduction to Glaze Chemistry Part 1
czcams.com/video/qOZ3s_0YO7c/video.html An Introduction to Glaze Chemistry Part 2
@@WashingtonStreetStudios thanks!!
Would that make any sense to add wood ash as flux to an oxide wash?
Since the wash is not a glaze, adding wood ash, or a flux, would not have a predictable or repeatable outcome.
How long have you been in Harpersferry? I lived in Inwood for three years.
We opened in August 2017.
Can Engobe be applied on bone dry clay or a bisque?
Yes to both
I'm making underglaze pastels and pencils using mason stains and EPK Kaolin. Can iron oxide be used like mason stains in chalk? I'm trying to make soft pastels as the commercial chalks are very hard.
Rosie, I've sent this question off to Phil and will post his response. Thank you for the question, it's a good one!
Hi Rosie,
Thanks for your email and your question. Plain iron oxide will not be as stable as Mason stains, meaning that it will tend to dissolve in a lot of glazes that are applied over it, and the color will fade away or disappear. Mason stains are pre-fired / pre-reacted colored compounds that are designed not to dissolve at low (earthenware) firing temperatures.
Good luck, Phil
@@WashingtonStreetStudios Thank you so much.
If any person can tell about online class of glaze compound &glaze chemistry of tiles. I need very... I want to new somthing in glaze.. So 🙏 tell me and drop the link..
Sorry, Phil was our glaze chemistry expert and he died last year. John Britt has some excellent material on his channel and I highly recommend it (www.youtube.com/@johnbrittpottery).
23:17 Sean Connery: are you saying it should be stirred, not shaken?
Yes, you got it!
At 05:21 you give an example on something that can be used as a flux.. I can't hear what's been said.. phonetic I hear "glystry gory" can anyone help me out?
Sorry it took a while to respond, Phil suggested adding Gerstley Borate as a flux. And another videos he has suggested taking a small sample to test at a new material, rather than adding it to the entire batch. I hope this helps!
⭐️⭐️⭐️⭐️⭐️
Thanks
Does anyone know why yellow spots appear on liquid clay after baking? And can it be prevented?
The yellow spots are likely impurities in the clay body. What temperature or cone are you firing to? If you fire to cone 6 or above, most of the impurities should burn off. If it turns darker, it's a more substantial impurity like iron oxide.
Back when amaco underglaze 2 ounce jars were 2..3..4 dollars. Lol.
Yes indeed, prices have changed!
Great talk. Please drop the highly distracting music.
Sorry Dottie, if you find it too distracting, perhaps you can find the information elsewhere.