Daniel Semler on wed 27 sep 06
Hi Jane,
I guess its not too surprising its matte at cone 10. There's very =20
little silica for all that alumina. Normally to lower the temp I'd say =20
drop clay and rebalance for silica vs alumina but in this case I'd be =20
inclined to try more silica and get it too gloss up a little. I think =20
its just got too little silica to glass up at that temp. You could do =20
a line blend just adding silica. There is however a little problem. =20
I'm not really sure what your crystals are but I'd guess wollastonite =20
or pyroxene, maybe both. I'm guessing that your kiln cooled slowly and =20
the glaze crystallised as it cooled.
Having said all that one thing that concerns me is that changing =20
the si:al ratio might affect what you have in the surface, but you =20
want to change that anyway. So I think that what you may be looking =20
for is a sort of gloss that crystallises well on cooling. Something =20
with a bunch of whiting can do that. You could lower the alumina a =20
little to loosen things up a little too which might help =20
crystallisation a little too.
I would certainly be interested in seeing pics and might be able to =20
offer more after that.
Thx
D
Jane Murray-Smith on wed 27 sep 06
Hi,
I need some suggestions as to how to tweak a high fire glaze recipe that
is a little dry and not too interesting at cone 10 but has beautiful tiny
crystals and a glassier surface beyond cone 12? (It would take too long to
explain how this happened, but the entire bottom of the kiln was very
overfired, and I only had cone 11 in the pack and the number was so melted
it was unreadable))
I was thinking of a line blend with the original recipe on one end, but
need advice on what to try on the other to get it to mature at a lower
temperature.
nep sye 55
whiting 16
talc 13
kaolin 16
I can email photos of the effects I am looking for if anyone wants to mail
me off list.
I am open to another recipe that would result in a similar effects..
janepots@shaw.ca
Thanks, Jane
Ron Roy on thu 28 sep 06
Hi Jane,
Do a five part line blend lowering the clay.
Number 1 has 15 EPK
Number 5 has 11 EPK
Mix 500 grams of each.
To get #3 mix equal amounts of 1 and 5
To get #2 mix equal parts of 1 and 3
3 and 5 gives #4
Remember - when you take clay out of a glaze you may get running.
RR
On 27-Sep-06, at 6:58 PM, Jane Murray-Smith wrote:
> Hi,
> I need some suggestions as to how to tweak a high fire glaze recipe
> that
> is a little dry and not too interesting at cone 10 but has beautiful
> tiny
> crystals and a glassier surface beyond cone 12? (It would take too
> long to
> explain how this happened, but the entire bottom of the kiln was very
> overfired, and I only had cone 11 in the pack and the number was so
> melted
> it was unreadable))
> I was thinking of a line blend with the original recipe on one end, but
> need advice on what to try on the other to get it to mature at a lower
> temperature.
>
> nep sye 55
> whiting 16
> talc 13
> kaolin 16
>
> I can email photos of the effects I am looking for if anyone wants to
> mail
> me off list.
> I am open to another recipe that would result in a similar effects..
> janepots@shaw.ca
>
> Thanks, Jane
>
> _______________________________________________________________________
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>
Ron Roy
RR#4
15084 Little Lake Rd
Brighton, Ontario, Canada
K0K 1H0
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