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Author Topic: AAAUUUUGGGHHHHHHHHH!!!!!!!!!  (Read 2212 times)

Cyndy

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Re: AAAUUUUGGGHHHHHHHHH!!!!!!!!!
« Reply #5 on: November 16, 2015, 03:28:48 PM »

Porcelain is what porcelain wants to do.........I've had pots make it all the way to the glaze fire, then crack. I've had porcelain fire in a wood fire and come out better than any of the other clays. Persnickety stuff. But we love the outcome.
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Wetherby

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Re: AAAUUUUGGGHHHHHHHHH!!!!!!!!!
« Reply #4 on: November 09, 2015, 10:14:33 PM »

Deb,
I had similar experience with Ice cone 6 porcelain.  I compressed the clay, the walls/floor where the same thickness, dried covered very slowly, etc.  It cracked during slow bisque.  Took a hammer to it.

Sharon
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Arnold Howard

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Re: AAAUUUUGGGHHHHHHHHH!!!!!!!!!
« Reply #3 on: November 09, 2015, 05:51:47 PM »

I've seen the same types of cracks in fused glass where a change in thickness of glass occurs.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
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rbogle

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Re: AAAUUUUGGGHHHHHHHHH!!!!!!!!!
« Reply #2 on: November 08, 2015, 09:35:16 PM »

Bummer Deb.....I do very little handbuilding and have never handbuilt with porcelain....but that sure is a lot of cracking!!

I'm guessing it might be good to make the next set with a white stoneware or maybe a different porcelain?

As I was pondering this I did remember a time when I rolled out some small porcelain slabs and I didn't use clay fresh from the bag.  I used porcelain scraps that I had left over from some previously slabs.  I smushed them all together and then rolled out another slab.....everything looked great and all was well during drying....at bisque I saw a couple of very small cracks....after glaze there were several much larger cracks.  The moral of my story is that I should always used fresh or well wedged clay before rolling out a slab.

Maybe that helps??

Ray

Deb Thuman

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AAAUUUUGGGHHHHHHHHH!!!!!!!!!
« Reply #1 on: November 08, 2015, 07:30:23 PM »

I used ^6 porcelain and bisque fired to ^03. When I rolled out the slabs, I used a rolling pin and rolled in every direction. I did stack the planter pots on top of the drip plates - although I did that last time and had no problems.

It was 55 degrees when I started and I took the temp up slow. At least I thought it was slow enough. I live in a desert and these pieces had been drying for at least a month. They were bone dry.

What went wrong? I'm going to use patch attach on the cracks. The pots were made for my use and I want to try to save my work.

TIA
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