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mending a big crack in bisque, rick mahaffey's recipe

updated thu 2 nov 06

 

normana on wed 1 nov 06


nancy,
it can be repaired with paperclay,am assuming it is in bisque state, it
might take two firings to do it, depending on the width of the crack,
not at all hard to do,. weather it is worth doing, thats your call.
norman aufrichtig

Vince Pitelka wrote:
> Nancy wrote:
>> Have you done this on a functional piece? I made a large pasta bowl and
>> did
>> a lot of carving detail on the outside. I dried it like I always do but
>> let
>> someone else load the kiln and inside the bowl they placed 5 other
>> pieces.
>> I have a crack across the entire bottom and it goes through the piece.
>> I'm
>> not sure if I try to fix it that it will be as strong as if I just
>> rethrow
>> it.
>
> Nancy -
> It is never worth it trying to fix a functional pot, unless you are
> talking
> about something on the magnitude of Adelaid Alsop Robineau's
> "1000-hour-jar," which she is rumored to have spent 1000 hours
> carving. In
> that case, it did crack in the bisque, and she did repair it. Otherwise,
> your time is far better spent chalking this up to experience and making
> another pot.
>
> If your bowl cracked across the bottom and not up either side, then I
> don't
> think you can blame it on how it was stacked in the bisque firing. That
> kind of crack usually comes from lack of compression in throwing, or from
> uneven drying. A common scenario is when a freshly-thrown bowl or
> plate is
> left out in the open too long, and the walls and outer edge of the base
> start to stiffen, while the center bottom is much wetter and is only
> drying
> from the upper surface. Later on it has to "catch up," and a crack
> appears.
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft, Tennessee Technological University
> Smithville TN 37166, 615/597-6801 x111
> vpitelka@dtccom.net, wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka/
> http://www.tntech.edu/craftcenter/
>
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