"Ron Roy (by way of Richard Gralnik on tue 12 oct 99
Ron Roy dug up this bit of helpful information for me and I thought I'd share
it with the list:
Since this glaze recipe calls for copper oxide and I don't have any I
wondered if you could substitute copper carb. The next question is how
much copper carb to use instead. Ron's answer (Thanks!) -
For every 1.0 of copper oxide you will need 1.3 of carbonate.
Richard
----------------------------Original message----------------------------
Hi Patty,
I'm guessing this is a cone 10 glaze. I have used frit 3134 to get some raw
clay into the recipe - it will stay suspensed much better. I'm fairly sure
this will look very close to your original and has the added advantage of
having a lower expansion which should help with the crazing.
RR's revision
-----------------
F4 SPAR............. 46.00
F3134............... 10.00
WHITING............. 19.00
OM-4................ 10.00
SILICA.............. 15.00
BENTONITE........... 2.00
TIN................. 3.00
COPPER OX........... 3.50
----------
Total............... 108.50
If it works you can then mix up a big batch and add some of the older
recipe to it and use it up over several batches.
RR
>----------------------------Original message----------------------------
>I am having a problem with one of my glaze recipes and would appreciate some
>advice. After sitting unused between glazing sessions, this particular glaze
>settles to the bottom as a thick, almost dry cake. I must drain all the
liquid
>and then chip away the settled ingredients which was about 3 inches thick and
>add it back to the liquid. After the last time I used it, I added a
commercial
>glaze stabilizer. Although it has stabilized the glaze so that it no longer
>settles, it is now so thick that it not only takes a longer time to dry
when I
>dip my pieces for glazing, but the fired glaze no longer looks as nice as
>it did
>before I added the stabilizer. Question #1: Can I salvage the remainder
of my
>glaze? Question #2: Is there a substitution I can make in future batches to
>avoid this problem?
>
>The recipe is as follows:
>
>Soda feldspar 5500g
>Whiting 2200g
>Bentonite 200g
>Flint 1400g
>Tin oxide 300g
>Copper oxide 365g
>
>Any help or suggestions would be greatly appreciated!
>
>Patty Herr, Potter
>therr@earthlink.net
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Edouard Bastarache on wed 13 oct 99
------------------
Hello all,
James Chappell says the following on page 419 of =22The Potters Complete =
Book of
Clay and Glazes:
1-=22Copper carbonate
(...)
Copper oxide can be used as a substitute if the amount is reduced by
one-half=22
2-=22Copper oxide
(...)
Copper carbonate can be substituted for copper oxide if the amount is
doubled=22
Later,
Edouard Bastarache
edouardb=40sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/=7Eedouardb/
-----Message d'origine-----
De : Ron Roy (by way of Richard Gralnik =3Crgralnik=40desktalk.com=3E)
=3Cronroy=40pop.total.net=3E
=C0 : CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
Date : 12 octobre, 1999 14:54
Objet : Copper Oxide/Copper Carbonate conversion factor
----------------------------Original message----------------------------
Ron Roy dug up this bit of helpful information for me and I thought I'd =
share
it with the list:
Since this glaze recipe calls for copper oxide and I don't have any I
wondered if you could substitute copper carb. The next question is how
much copper carb to use instead. Ron's answer (Thanks=21) -
For every 1.0 of copper oxide you will need 1.3 of carbonate.
Richard
----------------------------Original message----------------------------
Hi Patty,
I'm guessing this is a cone 10 glaze. I have used frit 3134 to get some raw
clay into the recipe - it will stay suspensed much better. I'm fairly sure
this will look very close to your original and has the added advantage of
having a lower expansion which should help with the crazing.
RR's revision
-----------------
F4 SPAR............. 46.00
F3134............... 10.00
WHITING............. 19.00
OM-4................ 10.00
SILICA.............. 15.00
BENTONITE........... 2.00
TIN................. 3.00
COPPER OX........... 3.50
----------
Total............... 108.50
If it works you can then mix up a big batch and add some of the older
recipe to it and use it up over several batches.
RR
=3E----------------------------Original message----------------------------
=3EI am having a problem with one of my glaze recipes and would appreciate =
some
=3Eadvice. After sitting unused between glazing sessions, this particular =
glaze
=3Esettles to the bottom as a thick, almost dry cake. I must drain all the
liquid
=3Eand then chip away the settled ingredients which was about 3 inches thick=
and
=3Eadd it back to the liquid. After the last time I used it, I added a
commercial
=3Eglaze stabilizer. Although it has stabilized the glaze so that it no =
longer
=3Esettles, it is now so thick that it not only takes a longer time to dry
when I
=3Edip my pieces for glazing, but the fired glaze no longer looks as nice as
=3Eit did
=3Ebefore I added the stabilizer. Question =231: Can I salvage the =
remainder
of my
=3Eglaze? Question =232: Is there a substitution I can make in future =
batches to
=3Eavoid this problem?
=3E
=3EThe recipe is as follows:
=3E
=3ESoda feldspar 5500g
=3EWhiting 2200g
=3EBentonite 200g
=3EFlint 1400g
=3ETin oxide 300g
=3ECopper oxide 365g
=3E
=3EAny help or suggestions would be greatly appreciated=21
=3E
=3EPatty Herr, Potter
=3Etherr=40earthlink.net
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
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