Jump to content


Photo
- - - - -

Breakage

Tiles breakage firing

  • Please log in to reply
33 replies to this topic

#1 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 19 July 2014 - 01:27 PM

Can anyone tell me why these broke during 04 firing? 4 out of 6 broke. Are these cooling breaks? I used paragons schedule that they have on you tube. But during the cooling phase the alarm sounded and flashes FTC (failure to cool). I don't understand that since this is what paragon is showing to do. Very confused.

Thanks
Linda

Attached Files



#2 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 4,064 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 19 July 2014 - 05:45 PM

I think we need more information. What is the clay? How were these stacked? How large are they. Were they dry? was it the top tile of each stack that broke?Did you have anything..like grog underneath them or in between them?

 

I am not familiar with the failure to cool alarm? Did the kiln not shut off?

 

Sorry for your loss. 

 

Marcia



#3 clay lover

clay lover

    Advanced Member

  • Members
  • PipPipPip
  • 939 posts
  • LocationSoutheast

Posted 19 July 2014 - 07:41 PM

Ditto. , never saw 'failure to cool' ???



#4 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 19 July 2014 - 08:43 PM

Totally dry. 3 weeks + in drying. Cone 5 B Mix Laguna. 12" tiles at 1/2" thickness. I stacked 4 on middle shelf and stacked 2 with 1 bullnose and triangles on top shelf. The 2 on top shelf broke. 2 of 4 broke on the middle shelf (4 stacked). The top one and bottom one broke. The bottom shelf had triangles and small bullnose with no problems. Had nothing underneath nor in between. I was told by Angela Pozo I could stack at least 4 safely. But no more. Hope this helps. Thank you.

Firing schedule I programmed:
Cone 04
Speed Medium (standard)
Preheat 1 hour
Hold 10 minutes
Cool 200* per hour

#5 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 4,064 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 19 July 2014 - 10:07 PM

Four seems like a lot but can't explain the top and bottom cracking. I fire my large slabs on edge. I have done that with small 4x4 tiles as well.
Marcia

#6 Min

Min

    Advanced Member

  • Members
  • PipPipPip
  • 575 posts
  • LocationCanada

Posted 20 July 2014 - 12:24 AM

I don't make tiles but my thoughts would be that firing a 2" total thickness of fine clay tiles on your middle shelf at the preprogrammed med speed with only a 1hr candle is just too fast. Even the 1" thickness might be too much for that fast a firing. 



#7 Babs

Babs

    Advanced Member

  • Members
  • PipPipPip
  • 1,119 posts

Posted 20 July 2014 - 12:43 AM

Top ones too fast temp increase and decrease.

Bottom ones shelf  a bit rough , tile adhering in places, weight of tiles too much??



#8 clay lover

clay lover

    Advanced Member

  • Members
  • PipPipPip
  • 939 posts
  • LocationSoutheast

Posted 20 July 2014 - 06:57 AM

in my Skutt, medium is too fast for everything.



#9 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 20 July 2014 - 09:52 AM

Oops. Sorry. Looked back at what I wrote down. I did slow speed. Maybe that's why the FTC alarm sounded? If I fire them standing up on edge this large will they not warp? Would I leN them against ghe sides of the kiln? I have another large batch of large tiles to fire. It may be easier/quicker and more foolproof for me to fire single layer then have to go back and wait 3 weeks for drying? Marcia how large are the ones you fired on edge? I do have tile setters. Will those work on tiles this large? Thank you for all of your help!

#10 Chris Campbell

Chris Campbell

    clay stained since 1988

  • Members
  • PipPipPip
  • 2,284 posts
  • LocationRaleigh, NC

Posted 20 July 2014 - 11:17 AM

What can you tell us about the ones that did not crack?

I have never seen cracks like these ... Smooth and contoured.

Chris Campbell
Contemporary Fine Colored Porcelain
http://www.ccpottery.com/

https://www.facebook...88317932?ref=hl

TRY ...   FAIL ...  LEARN ...  REPEAT


#11 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 20 July 2014 - 11:40 AM

What can you tell us about the ones that did not crack?
I have never seen cracks like these ... Smooth and contoured.


They came out perfect. Which is odd because one was the second from bottom and the other was top one of 4 and in middle of kiln.

#12 Chris Campbell

Chris Campbell

    clay stained since 1988

  • Members
  • PipPipPip
  • 2,284 posts
  • LocationRaleigh, NC

Posted 20 July 2014 - 01:40 PM

The cracks don't seem to follow any pattern I have seen. They don't look like stress cracks or jagged weight cracks or fast cooling ... :unsure:

 

Going back to construction ... did you mix together any small bags of leftover clay?


Chris Campbell
Contemporary Fine Colored Porcelain
http://www.ccpottery.com/

https://www.facebook...88317932?ref=hl

TRY ...   FAIL ...  LEARN ...  REPEAT


#13 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 4,064 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 20 July 2014 - 02:22 PM

Could you have caused any stress when drawing the patterns?

 

Marcia



#14 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 20 July 2014 - 04:08 PM

No no mixing of the clays. Here is my process that I go through step-by-step.

I cut the clay right out-of-the-box from Laguna Clay I cut each pug in thirds which is exactly what I need to cut out one tile. I then roll it through my slab roller. II which is also brand new. I might mention too that my kiln is new and only used 3 times...once was the conditioning firing. I started out on one and between two canvases and roll it at 3 inches first. I I turn it and then I roll it at about 2 1/2 inches. I continued do this until I reach the 7/8 inch mark which is where it needs to be 1/2 inch after the final firing. I think carefully place a sheet rock underneath the tile. And then place one on top so that I can remove the canvases. I then just trace my pattern onto the wet clay very lightly. I've been trim off the excess clay leaving about half inch all the way around. I sandwich the tile between two pieces of sheet rock to dry to leather hard stage. I've been trim the tile to the actual tile pattern and then I traced my design on top. I'll let that dry another three hours. I then carve my design. I do that about 3 times because I'm doing it very lightly to go in little by little. I'm actually just outlining it all so there's some definition between the background and the actual design. I never rest my whole hand on the tile I'm only using my fingertips. I've been put the sheet rock back on top and place it on the drying rack. Then I flip it every 24 hours for three days for drying evenly. And replacing sheet rock as it becomes wet. During the whole process of drying I do keep it covered with sheet of plastic After that I take it off completely and put it on a heavy-duty wire industrial baking rack to dry completely. I llet all tiles dry for three weeks before I clean them up ready to fire for bisque firing. Thank you everyone for your trying to help.

#15 High Bridge Pottery

High Bridge Pottery

    Advanced Member

  • Members
  • PipPipPip
  • 511 posts
  • LocationNewcastle Upon Tyne. England

Posted 20 July 2014 - 04:28 PM

I quite like the cracks, it looks a bit like a person.



#16 JBaymore

JBaymore

    Moderator

  • Moderators
  • 3,023 posts
  • LocationWilton, NH USA

Posted 20 July 2014 - 04:29 PM

Does anyone ELSE have access to your studio where the kiln is?

 

best,

 

.......................john

 

PS: I've only seen cracking like this in 40+ years from one type of thing.


John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

http://www.JohnBaymore.com

#17 Chris Campbell

Chris Campbell

    clay stained since 1988

  • Members
  • PipPipPip
  • 2,284 posts
  • LocationRaleigh, NC

Posted 20 July 2014 - 04:46 PM

What was that one thing? I've never seen this kind of cracking.

Chris Campbell
Contemporary Fine Colored Porcelain
http://www.ccpottery.com/

https://www.facebook...88317932?ref=hl

TRY ...   FAIL ...  LEARN ...  REPEAT


#18 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 20 July 2014 - 04:53 PM

Does anyone ELSE have access to your studio where the kiln is?
 
best,
 
.......................john
 
PS: I've one seen cracking like this in 40+ years from one type of thing.


No.just me and my husband here and he stays clear. What was that one thing?

#19 JBaymore

JBaymore

    Moderator

  • Moderators
  • 3,023 posts
  • LocationWilton, NH USA

Posted 20 July 2014 - 04:58 PM

Looks like the stack of tiles were put down hard.  Broken in handling.

 

I was wondering if someone else had picked up that stack and set it down harder than it should have been.

 

Other that that........ I've never seen that kind of cracking.  Bizzare.

 

best,

 

.....................john


John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

http://www.JohnBaymore.com

#20 JoLinDesigns

JoLinDesigns

    Advanced Member

  • Members
  • PipPipPip
  • 44 posts

Posted 20 July 2014 - 05:30 PM

Looks like the stack of tiles were put down hard.  Broken in handling.
 
I was wondering if someone else had picked up that stack and set it down harder than it should have been.
 
Other that that........ I've never seen that kind of cracking.  Bizzare.
 
best,
 
.....................john



Only I handle them and I placed them very gently one x one so I know that wasn't it. I never picked up more than one tile at any time during the whole process. Yes. Bizarre!! Thank you.





Also tagged with one or more of these keywords: Tiles, breakage, firing

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users