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cracks when rolling clay coils


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#1 JoyB

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Posted 25 July 2012 - 06:56 AM

Hi everyone. I am having problems with cracks appearing when I roll a coil and bend it into a round. I try to keep the clay as damp as possible and roll the coil on marble. When I roll onto a rubber mat to make a design in it its fine, its only when I come to bend the coil. My stoneware clay is about 12months old but I have tried it with new bags and get the same result. I have even put WD40 on the rubber mat to help with rolling but when I bend it still cracks. I watch dvd's of people doing this and they dont have cracks so I wonder what I am doing wrong? I hope someone can help?

Cheers Joy

#2 Lucille Oka

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Posted 25 July 2012 - 07:56 AM

The clay is probably too dry. Make it wetter not just on the outside but the ball or wad that you are using and re-wedge so that the moisture is evenly distributed throughout the lump. Also extruding the coil can help eliminate cracks as well; as the clay pushes through the die the cracks will be healed.


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#3 Chris Campbell

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Posted 25 July 2012 - 10:10 AM

I roll coils on damp surfaces ... Spray water on your canvas or cloth, not your clay. Wetting the clay directly just creates a slippery outer surface not a evenly soft clay. If the clay is too hard and dry to work with, try wrapping it in a damp towel and place it in a plastic bag overnight to rehydrate it.

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#4 Karen B

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Posted 25 July 2012 - 11:18 AM

Hi everyone. I am having problems with cracks appearing when I roll a coil and bend it into a round. I try to keep the clay as damp as possible and roll the coil on marble. When I roll onto a rubber mat to make a design in it its fine, its only when I come to bend the coil. My stoneware clay is about 12months old but I have tried it with new bags and get the same result. I have even put WD40 on the rubber mat to help with rolling but when I bend it still cracks. I watch dvd's of people doing this and they dont have cracks so I wonder what I am doing wrong? I hope someone can help?

Cheers Joy



A foolproof way is to roll your coils on a slab of clay. Works wonders.

#5 bciskepottery

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Posted 25 July 2012 - 07:19 PM

As you bend your coil, also push it inwards.

#6 JoyB

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Posted 26 July 2012 - 02:31 AM

Thanks to all for your info and I will give it a go

Cheers

Joy

#7 Mel21

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Posted 27 July 2012 - 12:53 PM

Hi everyone. I am having problems with cracks appearing when I roll a coil and bend it into a round. I try to keep the clay as damp as possible and roll the coil on marble. When I roll onto a rubber mat to make a design in it its fine, its only when I come to bend the coil. My stoneware clay is about 12months old but I have tried it with new bags and get the same result. I have even put WD40 on the rubber mat to help with rolling but when I bend it still cracks. I watch dvd's of people doing this and they dont have cracks so I wonder what I am doing wrong? I hope someone can help?

Cheers Joy



Hi Joy,

If your using a stoneware that is too gritty or even has the finest of grog in, it will be prone to cracking more so when rolling or bending than a smooth throwing stoneware such as Earthstone Extra Smooth. It could also be that your clay is too dry/of an inconsistent moisture content. If you wanted, you could dry it out completely, crush it up into reasonably small pieces, slake it down with water (leave it to soak in the water until saturated, probably overnight, then pour off excess water, squash it in your hands to make an even consistency throughout, put on a plaster bat to soak most of the water out until it reaches a soft kneading consistency and then re knead to start from scratch - at least then you know that the moisture content is even all the way through and it is not too dry or dryer in some areas than others - if it is a year old I suspect this is the most likely cause of your problems - so try it.

Best,

Mel




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