Jump to content
Sign in to follow this  
mudma1999

COOL ICE - CONE 6 - PORCELAIN CLAY

Recommended Posts

mudma1999    0

When I was in Tacoma they were out of the NZ6 so I have had to order it from my local supplier at almost double the price, it came in last week so I can't wait to try it as I have another trip planed to go down south in August. If it works as well for me as it did for Heidi I will coming back with a car full!

Share this post


Link to post
Share on other sites
Min    778

Thanks for posting your results Heidi. How is glaze fit with NZ6?    Min

Share this post


Link to post
Share on other sites
Heidi K    2

Thanks for posting your results Heidi. How is glaze fit with NZ6?    Min

 

I've been having some trouble, but I've found many that fit fine.

I don't mix my own glazes yet, and many of the glazes I use are made at Seattle Pottery Supply. All of the glazes I have from there fit fine except my favorite, shadow green, which doesn't fit at all (the glaze cracks and will either chip off the piece or crack the clay if the clay is thin).

Amaco's PC Ancient Jasper doesn't seem to fit it (though I only tested it on one pair of earrings - the glaze cracked off the earrings), Laguna's Caribbean Crackle crackled to the point that it cracked the bowl I used as a tester, and Coyote's Gun Metal Green sometimes fits it. The first two tests were just at the rim over clear, and it seemed to fit fine (though with a smooth crackle effect), and then the third time it got so crackly that it gave the piece a hairline crack. I forgot that and used it again since, and it worked out beautifully (without the clear underneath it, and it didn't crackle), so more testing is needed with that one.

Share this post


Link to post
Share on other sites
oldlady    1,323

jim,  the store associated with Clay Times in Hamilton, va is closing since Polly Beach is moving to st augustine, fl.  on your recommendation, i bought 100 pounds of frost since it was half price.  there were 2 bags left when i closed the store yesterday, saturday.  it is still open today and will be tomorrow.  do you want to contact them to purchase the last of the Frost?  the number is 540-338-4249.  see www.theartspot.co       there is no 'm' BUT MAYBE THAT IS A TYPO.  oh, cropp. caps lock again. 

Share this post


Link to post
Share on other sites
OffCenter    82

Wow! Thank you, oldlady. That's very nice of you. I'll call them but the shipping will probably negate the savings. If Heidi wants it (Let me know, Heidi), she can have first dibs but I think she is in the Northwest and the shipping for her would really be a killer.

 

Chris and I disagree on which porcelain, Frost of Southern Ice, is the most translucent. Southern Ice is a beautiful clay that is a dream to handle but I think Frost is just a little bit more translucent. Cool Ice is supposed to be Southern Ice for cone 6. It is not nearly as translucent as Frost or NZ6. I hope you like Frost. My old pottery professor saw one of my Frost bowls at a show and the next time he saw me he said "Where the hell did you learn to throw glass!" Let me know what you think of it.

 

Jim

Share this post


Link to post
Share on other sites
oldlady    1,323

was there some question about a bad batch of frost?  i haven't found anyone to help get the boxes into the studio yet ( the strong young men avoid going past my house)  and i do not know how long it was at the store.  if there is a date of manufacture on the box i can check with the maker to see if it is a good or a bad one.

Share this post


Link to post
Share on other sites
OffCenter    82

was there some question about a bad batch of frost?  i haven't found anyone to help get the boxes into the studio yet ( the strong young men avoid going past my house)  and i do not know how long it was at the store.  if there is a date of manufacture on the box i can check with the maker to see if it is a good or a bad one.

 

I bought the bad Frost several years ago. I bought a lot of it so it lasted a long time. I doubt yours is from that batch. If you throw a couple of mugs with it and the bottom cracks no matter how much you compress and work the bottom, then you have a bad batch that you can only fix by putting a little paper in it.

 

Jim

Share this post


Link to post
Share on other sites
Biglou13    202

any of you clay  gurus....

 

what, or why is one clay more translucent than others?

 

is it the type of porcelain in the clay body? is epk, grolleg, tile 6, helmer  more translucent than another?

 

if so whats your guess?

Share this post


Link to post
Share on other sites
Matt Oz    67

any of you clay  gurus....

 

what, or why is one clay more translucent than others?

 

is it the type of porcelain in the clay body? is epk, grolleg, tile 6, helmer  more translucent than another?

 

if so whats your guess?

 

The short answer is the purity of the kaolin, all the clay bodies discussed in this topic are using a very pure New Zealand kaolin (technically a halloysite), that explains the NZ in NZ6.

Share this post


Link to post
Share on other sites
Min    778

 

Thanks for posting your results Heidi. How is glaze fit with NZ6?    Min

 

I've been having some trouble, but I've found many that fit fine.

I don't mix my own glazes yet, and many of the glazes I use are made at Seattle Pottery Supply. All of the glazes I have from there fit fine except my favorite, shadow green, which doesn't fit at all (the glaze cracks and will either chip off the piece or crack the clay if the clay is thin).

Amaco's PC Ancient Jasper doesn't seem to fit it (though I only tested it on one pair of earrings - the glaze cracked off the earrings), Laguna's Caribbean Crackle crackled to the point that it cracked the bowl I used as a tester, and Coyote's Gun Metal Green sometimes fits it. The first two tests were just at the rim over clear, and it seemed to fit fine (though with a smooth crackle effect), and then the third time it got so crackly that it gave the piece a hairline crack. I forgot that and used it again since, and it worked out beautifully (without the clear underneath it, and it didn't crackle), so more testing is needed with that one.

 

 

Thanks very much for taking the time to write all this! Sounds like you are getting dunting/shivering from several of the glazes you tried. Did Tacaoma Clayart offer any suggestions as to glaze coe? (You might be able to add some high expansion frit to your shadow green and the other dunting glazes to help fit but then you would probably have to tinker with the alumina and silica also.) It's unusual for commercial glazes to dunt, usually they err on the side of caution and use a higher coe. Is there a chance that the glaze layer was thicker than the clay, especially with the Caribbean Crackle or shadow green?

 

Min

Share this post


Link to post
Share on other sites
Heidi K    2

Wow! Thank you, oldlady. That's very nice of you. I'll call them but the shipping will probably negate the savings. If Heidi wants it (Let me know, Heidi), she can have first dibs but I think she is in the Northwest and the shipping for her would really be a killer.

 

Thanks Jim, but yes, I think shipping would be a killer. I'll stick with NZ6 until I see Frost at Seattle Pottery Supply.

Share this post


Link to post
Share on other sites
OffCenter    82

 

any of you clay  gurus....

 

what, or why is one clay more translucent than others?

 

is it the type of porcelain in the clay body? is epk, grolleg, tile 6, helmer  more translucent than another?

 

if so whats your guess?

 

The short answer is the purity of the kaolin, all the clay bodies discussed in this topic are using a very pure New Zealand kaolin (technically a halloysite), that explains the NZ in NZ6.

 

 

Yeah, I figured the NZ was for New Zealand. I've got a bag of New Zealand Kaolin (supposedly the purest kaolin in the world) and sometimes sub it in a test batch of glaze for EPK and other kaolins. There has to be a lot of kaolin in the recipe to make a difference. I've got to get around to trying NZ6. It may replace my Frost.

 

Jim

Share this post


Link to post
Share on other sites
Heidi K    2

 

 

Thanks for posting your results Heidi. How is glaze fit with NZ6?    Min

 

I've been having some trouble, but I've found many that fit fine.

I don't mix my own glazes yet, and many of the glazes I use are made at Seattle Pottery Supply. All of the glazes I have from there fit fine except my favorite, shadow green, which doesn't fit at all (the glaze cracks and will either chip off the piece or crack the clay if the clay is thin).

Amaco's PC Ancient Jasper doesn't seem to fit it (though I only tested it on one pair of earrings - the glaze cracked off the earrings), Laguna's Caribbean Crackle crackled to the point that it cracked the bowl I used as a tester, and Coyote's Gun Metal Green sometimes fits it. The first two tests were just at the rim over clear, and it seemed to fit fine (though with a smooth crackle effect), and then the third time it got so crackly that it gave the piece a hairline crack. I forgot that and used it again since, and it worked out beautifully (without the clear underneath it, and it didn't crackle), so more testing is needed with that one.

 

 

Thanks very much for taking the time to write all this! Sounds like you are getting dunting/shivering from several of the glazes you tried. Did Tacaoma Clayart offer any suggestions as to glaze coe? (You might be able to add some high expansion frit to your shadow green and the other dunting glazes to help fit but then you would probably have to tinker with the alumina and silica also.) It's unusual for commercial glazes to dunt, usually they err on the side of caution and use a higher coe. Is there a chance that the glaze layer was thicker than the clay, especially with the Caribbean Crackle or shadow green?

 

Min

 

 

Thanks Min,

 

Yes, I think I'm getting both dunting and shivering. Tacoma Clay Art told me I could try adding a certain frit (I wrote the number down in my studio) to try to increase the coe, but I haven't done it yet. I think I should experiment a little, because shadow green is a wonderfully reliable glaze otherwise and pairs well with so many of my other glazes that I would love to be able to use it on the NZ6, but as of yet I've just been lazy and have busied myself making lots of pure white pieces to showcase the translucence.

The piece that the Caribbean Crackle broke was thin at the bottom where the glaze pooled and got quite thick, so yes, I think it's likely that they were close to the same thickness or the glaze could have even been slightly thicker. The shadow green has never been close to the same thickness as the clay, but always shivers. The time it cracked the clay was on a saucer - the center of the saucer was maybe just under 1/8 of an inch thick (guessing, as it didn't break, only showed multiple crack lines on the unglazed bottom), and where the glaze chipped off I could see it was about 1/32" thick at the most. The glaze was also lifted slightly from the center of the saucer, so it really appeared to me that it wasn't shrinking as much as the clay and was therefore forced to arc as the clay shrunk.  I also tried it (shadow green) on a pair of earrings and the glaze came clear off the clay, like the ancient jasper did. It came off almost in one piece (it stuck slightly around the hole).

 

I can easily avoid the Caribbean Crackle or Ancient Jasper for anything I make with NZ6, but I'd really like to be able to use Shadow Green, so I'll see if I can find it in me to tinker and test.

Share this post


Link to post
Share on other sites
Heidi K    2

 

 

any of you clay  gurus....

 

what, or why is one clay more translucent than others?

 

is it the type of porcelain in the clay body? is epk, grolleg, tile 6, helmer  more translucent than another?

 

if so whats your guess?

 

The short answer is the purity of the kaolin, all the clay bodies discussed in this topic are using a very pure New Zealand kaolin (technically a halloysite), that explains the NZ in NZ6.

 

 

Yeah, I figured the NZ was for New Zealand. I've got a bag of New Zealand Kaolin (supposedly the purest kaolin in the world) and sometimes sub it in a test batch of glaze for EPK and other kaolins. There has to be a lot of kaolin in the recipe to make a difference. I've got to get around to trying NZ6. It may replace my Frost.

 

Jim

 

Jim,

I thought you might be interested to know - I just finally got a batch of frost tumblers out of the kiln yesterday, and without a doubt, the NZ6 is more translucent. I compared the entire batch, but specifically I picked a frost one that was particularly thin and light, and a NZ6 one that was slightly thicker, and still the NZ6 one had more translucence. I was pretty disappointed in the frost tumblers after working for months with the NZ6 (not to mention that my clear glaze crawled on EVERY SINGLE ONE). Looks like I'll be driving to Tacoma for my clay afterall!

Share this post


Link to post
Share on other sites
mudma1999    0

I just finished my first round of tests on NZ6 and Frost and I have to agree that NZ is by far more translucent, easier to throw and easier to trim. Most of my glazes fit fine except of course for the most used one, clear so I'm trying a low expansion made with 3249. It seems fine but I want to do some further testing with stains added. I will use up my remaining couple of boxes of frost but after that I'm on to NZ

I did notice that frost is still a little whiter but it cracks a lot so I was losing a fair bit of work.

Share this post


Link to post
Share on other sites
terrim8    79

The world is going crazy for New Zealand pure halloysite . It has an extremely low iron content- I think my supplier said less than 1/2 % iron contamination and I believe this article confirms that.It is from a very pure hydrothermal deposit in New Zealand. That means we can find it here if we try hard enough. North America has many hydrothermally formed deposits- just have to find the right one!

 

http://link.springer.com/chapter/10.1007/978-3-642-27682-8_42#page-1

 

https://en.wikipedia.org/wiki/Halloysite

Share this post


Link to post
Share on other sites
curt    117

Hehe, no need to die wondering!   ;) Dragonite from Utah is even better if clean halloysite is what you want.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×