Heidy Freyre on sun 29 oct 06
Some time ago (sorry I can't actually find it in the archives and didn't
note the date) Rick Mahaffey wrote:
"We use a slip made with vinegar and with cat-tail plant fibers added.
(Learned this from Fred Olsen, who learned it from Vivika Heino) Make it
thick and wet with vinegar then add slip, then burnish when the area
becomes leather hard. This often works when a bisque bowl is broken. With
a little skill you can make the damage dissappear. I have even filled
in missing areas that are not too big with the Cat-tail mender slip."
What I would like to know is, does the cat-tail plant have to be green or
would a brown dried one have the same effect?
And I suppose after the attempted reparation I would have to bisque the
piece again before glazing?
heidy
Marcia Selsor on sun 29 oct 06
Heidy,
I saw potters use cat tail fuzz in Uzbekistan to add to earthenware
for the clay for handles. This clay was really prone to cracking when
it dried. The cat tall fuzz reinforced the joint like the nylon fiber
we use to add to clay.
Wjat I would use for repairing a big crack in a bisqued piece is
paper clay spooze. Works great. Wet your bisque crack and fill.
I rebuilt some extensive cracking on an architectural piece including
adding parts that blew off.
I found that you really need to wet the bisque very well, work the
patching spooze and rebisque.
Marcia Selsor
http://marciaselsor.com
On Oct 29, 2006, at 6:53 AM, Heidy Freyre wrote:
> Some time ago (sorry I can't actually find it in the archives and
> didn't
> note the date) Rick Mahaffey wrote:
>
> "We use a slip made with vinegar and with cat-tail plant fibers added.
> (Learned this from Fred Olsen, who learned it from Vivika Heino)
> Make it
> thick and wet with vinegar then add slip, then burnish when the area
> becomes leather hard. This often works when a bisque bowl is
> broken. With
> a little skill you can make the damage dissappear. I have even
> filled
> in missing areas that are not too big with the Cat-tail mender slip."
>
> What I would like to know is, does the cat-tail plant have to be
> green or
> would a brown dried one have the same effect?
>
> And I suppose after the attempted reparation I would have to bisque
> the
> piece again before glazing?
>
> heidy
>
> _
Marcia Selsor
http://marciaselsor.com
Nancy on tue 31 oct 06
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
Vince Pitelka on tue 31 oct 06
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/
Hilltop Pottery on wed 1 nov 06
Vince
Nope, did not spend 1000 nor 100 nor 10 hours on the piece. Yes it did
crack across the bottom...about 1/3 of the way from the center and up
both sides. It just didn't come apart. I usually don't repair
anything, just use it for test glazing or nice garbage can additions.
Nancy
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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