Sandi Finney on wed 8 feb 06
I picked up the following Cone 9 Crackle Glaze and tried on stoneware and fired in gas reduction
to Cone 9/10. My results were a lovely translucent white shiny and WITHOUT crackling of any
kind.
Cornwall Stone 85
Whiting 15
Could anyone advise?
Pat Southwood on thu 9 feb 06
Sandi and others,
your recipe of
Cornish stone 85
whiting 15
is a bog standard base glaze for stoneware, from which many variants have
been extrapolated. If memory serves me correctly it is a Leach recipe from "
A potter's book"
It may well have crackled on someones clay body, but it is obviously a
good fit on yours!
You could try an e/w glaze on your s/w body (obviously fired at e/w temps.)
This will probably crackle because it is a bad fit, although you will not
have vitrified the clay, so it depends on your purpose.
Best Wishes
Pat Southwood
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Ron Roy on thu 9 feb 06
This glaze does not have a particularly high expansion/contraction rate and
your clay body probably has a higher than average expansion rate.
You may find some crazing will happen - or lowering it warm into ice water
may do it just right - or maybe just putting it on thicker.
the trouble with normal crazing is it usually gets smaller as time passes
and sometimes you want the large spaces.
So inducing crazing is better if you want the look to stay the same.
Here is a glaze that will probably craze for you - perhaps do a little line
blend - equal parts of this one and that one to try and find out when the
crazing starts.
It is very close to the original and very little clay - I would add 2%
bentonite to help keep it up in the bucket.
G 200 spar - 67.0 (can use Custer)
Whiting - 15.0
EPK - 4.0
Silica - 14.0
Total 100.0
RR
>I picked up the following Cone 9 Crackle Glaze and tried on stoneware and
>fired in gas reduction
>to Cone 9/10. My results were a lovely translucent white shiny and
>WITHOUT crackling of any
>kind.
>
>Cornwall Stone 85
>Whiting 15
>
>Could anyone advise?
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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