Jump to content


Photo

Unusual glaze problem


  • Please log in to reply
8 replies to this topic

#1 Jeanine Marie

Jeanine Marie

    Newbie

  • Members
  • Pip
  • 4 posts

Posted 08 May 2013 - 03:59 PM

I have what I think might be an unusual glaze problem. I made a decorative piece from Laguna #60 stoneware clay, which was bisque-fired at cone 04. I glazed the top of the piece by pouring a random pattern of dry orange shino glaze, letting that dry thoroughly, and then pouring a random pattern of luster shino. The rest of the piece remained unglazed. The piece was then fired to cone 10 in a gas reduction kiln. When the piece was unloaded, the luster glaze, where it overlapped with the dry orange shino, began to flake. It did not flake entirely away but left a layer underneath that looks granular, like sugar. It did not flake where there was no overlap with the dry orange shino. This doesn't seem like typical shivering when there is a misfit between the clay body and the glaze. I've used clay from this same batch and the same combination of glazes before without this problem. My searches of the web haven't turned up a problem exactly like this one. I'd be grateful to hear if anyone else has had a similar problem and ideas as to what might have caused it so I can avoid it in the future.

#2 TJR

TJR

    Advanced Member

  • Members
  • PipPipPip
  • 1,318 posts
  • LocationCanada

Posted 08 May 2013 - 04:02 PM

Any chance of a picture? That might help us figure this out.
TJR.

#3 neilestrick

neilestrick

    Neil Estrick

  • Members
  • PipPipPip
  • 2,841 posts
  • LocationGrayslake, IL

Posted 08 May 2013 - 05:05 PM

Lots of glazes don't play nice with shino, including other shinos. I would guess that is the root of the problem, however it may be an application problem. I wouldn't let your glazes dry too much between overlapping applications. Dry enough to pick up is dry enough. If totally dry, the first glaze layer can come loose from the pot when the second layer is applied.

Neil Estrick
Kiln Repair Tech
L&L Kilns Distributor
Owner, Neil Estrick Gallery, LLC
www.neilestrickgallery.com

neil@neilestrickgallery.com


#4 Jeanine Marie

Jeanine Marie

    Newbie

  • Members
  • Pip
  • 4 posts

Posted 08 May 2013 - 06:33 PM

Lots of glazes don't play nice with shino, including other shinos. I would guess that is the root of the problem, however it may be an application problem. I wouldn't let your glazes dry too much between overlapping applications. Dry enough to pick up is dry enough. If totally dry, the first glaze layer can come loose from the pot when the second layer is applied.


Thank you, Neil. I had no idea it was best not to let a glaze layer dry before applying a second glaze.

#5 Jeanine Marie

Jeanine Marie

    Newbie

  • Members
  • Pip
  • 4 posts

Posted 08 May 2013 - 06:35 PM

Any chance of a picture? That might help us figure this out.
TJR.


Hi, TJR. I'll try to get a photo of the problem and post it here. I'm afraid it will be hard to capture, but I'll do my best.

#6 TJR

TJR

    Advanced Member

  • Members
  • PipPipPip
  • 1,318 posts
  • LocationCanada

Posted 09 May 2013 - 08:17 AM


Any chance of a picture? That might help us figure this out.
TJR.


Hi, TJR. I'll try to get a photo of the problem and post it here. I'm afraid it will be hard to capture, but I'll do my best.


NEIL is a bit of a glaze expert around these parts. He may have answered your question for you. Layering of glazes is always tricky, Shinos especially.
TJR.

#7 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 2,110 posts
  • LocationCentral, PA

Posted 09 May 2013 - 09:15 AM



Any chance of a picture? That might help us figure this out.
TJR.


Hi, TJR. I'll try to get a photo of the problem and post it here. I'm afraid it will be hard to capture, but I'll do my best.


NEIL is a bit of a glaze expert around these parts. He may have answered your question for you. Layering of glazes is always tricky, Shinos especially.
TJR.


Even though I only work with ^6 these days, I have found over the years that it is a bad idea to let one glaze dry before applying a second over top. I usually pour/dip/splash on the first glaze, wait until no longer glossy, then apply the second glaze. My only other thought would be to wonder if that area of the kiln has a cold spot. You as the potter would know.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#8 OffCenter

OffCenter

    Advanced Member

  • Members
  • PipPipPip
  • 1,372 posts

Posted 09 May 2013 - 09:58 AM

Maybe the two glazes are on too thick? The best way to layer glazes is spraying. That way you can control the thickness of each glaze. Do let the glazes dry before another is added. This cup has 6 different glazes layered onto it. None are shinos but I've never found shinos to be any harder to layer than any other glaze. http://ceramicartsda...image&img=2562.

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#9 Jeanine Marie

Jeanine Marie

    Newbie

  • Members
  • Pip
  • 4 posts

Posted 09 May 2013 - 10:52 AM

Any chance of a picture? That might help us figure this out.
TJR.


Hi, TJR
Here is a photo of the problem. I hope it shows up clearly enough. Thank you once again for your help.
JeanineMarieAttached File  glazeproblem.jpg   446.27KB   28 downloads




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users