Marcia Selsor on thu 14 feb 02
Dear Ron,
In my class in Italy we used a terra cotta clay that actually softened
hands. made them feel great.
BUT
this clay had to be soaked in water 24 hours AFTER it was fired or it
would disintegrate.
It was true. I saw what must have been a similar clay in Spain actually
disintegrate after a bisque firing.
I am thinking there must be some sort of calcine going through changes.
Any clues?
Meanwhile I loved the softening qualtiy of this clay. My terra cotta
that I mix just sucks my hands dry.
Marcia in Montana
Ron Roy on fri 15 feb 02
Hi Marcia,
I am baffeled - could it be there is oil in that clay?
I remember doing some cement casting - black cement - Laforge or something
- I was firing it up to cone 10 and it was working just fine - then I
started adding stuff - like grog.
At a certain level of grog - I can't remember how much - the tiles would
disintegrate.
It was very strange - I would unstack the kiln and lean the tiles against
the wall - every once in a while I would think - now I am sure I left that
tile there - but it would not be there - I finally noticed the pile of
crumbes on the floor.
I stopped doing that - but did think it must be due to
expansion/contraction differences in the two materials.
RR
>In my class in Italy we used a terra cotta clay that actually softened
>hands. made them feel great.
>BUT
>this clay had to be soaked in water 24 hours AFTER it was fired or it
>would disintegrate.
>It was true. I saw what must have been a similar clay in Spain actually
>disintegrate after a bisque firing.
>I am thinking there must be some sort of calcine going through changes.
>Any clues?
>Meanwhile I loved the softening qualtiy of this clay. My terra cotta
>that I mix just sucks my hands dry.
>Marcia in Montana
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
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