Clay Bodies Free online Glaze Course #28

[@aubreytauer7308]

And thanks always for your great videos and for popping in to the Facebook group and on Glazy so often…we really appreciate it!

[@betsy5552]

Always happy to see a video from you. Thanks so match for sharing

[@johnbrittpottery]

Thanks for watching!

[@Montanacreate]

You are a hero.thanks for sharing your knowledge

[@johnbrittpottery]

Glad to help

[@nandeeshacharya1818]

Thank you sir 🙏

[@johnbrittpottery]

Most welcome

[@waynoswaynos]

Legendary. Thank you. But I wonder, if quartz acts as a flux in glazes, why is it a Filler in Clay recipes? With a locally dug low fire terracotta clay that melts at about cone 06, if I add quite a bit of beach sand (containing silica and some calcium) it extends out to around Cone 4 or 5. Making it more refractory. But if I add it to a Cone 10 body the melting temp comes down to a Cone 5 or 6. I find that curious. I am rolling with it but find it odd. SiO2 itself melts at 1670˚C so I would think it would drive the vitrification temp upward in every case.

[@johnbrittpottery]

@@waynoswaynos silica is a glass-former not a flux. Usually 325 mesh... Beach sand is probably 25 mesh.

[@waynoswaynos]

​@@johnbrittpottery Thanks John. I was thinking glass forming and fluxing was the same action. My local landscaping supply sells a 325 mesh silica sand and local beach sand feels about as dusty But, I'll try a thousand different clay body options overnight and see you at school tomorrow.

[@rabooshka101]

👍✨Thank you!!!!

[@farookmohammad1025]

thanks a lot ...🌻 I have question I want to learn how to build kiln and iam asking if there's a book you recommend it for me about kiln . thanks again from Iraq 🇮🇶

[@johnbrittpottery]

Not sure in your country..the kiln book by Fred Olsen...but mainly theory. I would try a Facebook group on kiln building ( unless there is no Facebook in Iran?) Or search on KZbin...probably lots on there. Then asknthe person for plans.

[@aubreytauer7308]

The 4th edition of the Kiln Book by Fred Olson has a lot of theory but also has a ton of actual plans and specific information on how to build walls, arches, using the different materials etc. It would be nice if he would add in a little more about electric kilns so that you could actually build one, and spend a little more time on burners…a lot of people actually make up their own burners but it can be very hard to find good information on that. It is hard to find used, I had to get it through inter library loan so I don’t know how easy it would be for you to get a hold of it, but Ian Gregory has two books on kilns that are very good although no where as detailed as Fred Olson’s book. A basic book that has tons of good information in it is Pioneer Pottery by Michael Cardew…an old book but still has great information in it, and is pretty cheap on eBay and used book sites. Pioneer Pottery has so much incredibly useful information if you don’t always have access to all the ceramic things that other country’s might have, it even teaches you how to find and process all the things you need to make clay and glazes, even how to make your own frits!

[@MichelDreyer-r8g]

Jonh thanks for sharing, do you have any idea where i can get the book you recommended Ceramic Science? I will love to read it, thanks again

[@johnbrittpottery]

Just Google it....probably expensive...but university library's have it FREE. App State, Brevard College in this area..check your area...Worldcat is the site...ISBN 10: 0801957281 ISBN 13: 9780801957284

[@MichelDreyer-r8g]

Thanks fot he feed back! @@johnbrittpottery

[@austinmassaquou705]

Thanks for your contents. I want to know if you crash these minerial stones (feldspars) by hand or by any mean without adding any other chemical to it. Can it melt when subjected to high temperature?

[@johnbrittpottery]

I usually bisque fired them. That loosens the bonds and they break down easier. Feldspar melts a bit at cone 9...try it woth store bought feldspar

[@aubreytauer7308]

There is no Parian/self-glazing porcelain available in the US, I am pretty desperate to find a workable, translucent recipe for both plastic clay and slipcasting. I have an analysis of one of the UK modern Parian bodies but unlike glaze analyses I can’t seem to reverse engineer it into a recipe. I have an old recipe from the 18th or 19th century, of 33% kaolin and 66% Cornish Stone, but that seems not at all possible to use as a plastic body and I’m not sure how translucent or self-glazing it would be, it says (this is from the Potter’s Dictionary by the Hamers) to fire at 1200C. Any advice on finding something that works since no one in the UK will ship to me in the US?

[@johnbrittpottery]

What cone?

[@aubreytauer7308]

@@johnbrittpottery I’d prefer cone 6, but I can do anywhere below that to cone 9 as long as it is vitrified and can make more than fairly small objects (like a tumbler cup). My primary interest is using it with stains for various kinds of colored clay applications, that could get quite large ideally, but would still have translucency in areas not stained and would negate the need for me to put a clear glaze on. I’m aware of some of the cone 04 frit porcelains and am not disinterested in them, they are just quite expensive being half or more frit and they seem because of the lack of any mullite to have a size limit. Valentine’s clay’s Parian has some really interesting information that hints at what kind of feldspar they use and they have a full analysis of the clay, with a HUGE amount of potassium in it, trying stuff out on my Insight Account has gotten me fairly close to their analysis but not close enough and I’m somewhat baffled what feldspar they are using…

[@johnbrittpottery]

I just put a new video...go to 16:48 minute ...there is a Val Cushing Parian recipe which might fit the bill.

[@aubreytauer7308]

@@johnbrittpottery I’ll check it out, if it is the one that has American kaolins and quite a bit of ball clay in it which I have seen before it wouldn’t be translucent, but perhaps if I substituted in Grolleg for all the clays the rest of the recipe would work for self-glazing- I got hung up on the one I saw likely not being very white or translucent, but didn’t think that as long as it self-glazes the clays can be altered to something more like the Parian they sell today, hopefully! Thanks!

[@johnbrittpottery]

Just sub in New Zealand kaolin. White!!! And Translucent! And if not vitreous add more flux.

[@DisVietVetUSA]

betcha arm is sore from all that writing

[@johnbrittpottery]

Think I got carpal tunnel. Did 2 huge ones. The one coming is printed and cut out!!