gary navarre on sun 27 feb 11
Hey Folks,=3D0A=3D0A I've made a decision to use some lower maturing glazes=
tow=3D
ard the tail of my kiln and am wondering if there are many formulas that ma=
=3D
ke a food safe ^4-^8 or ^10? My plan is to load the under fired ^10 pieces =
=3D
from earlier firings and load the mid-tail and tail settings with fresh pot=
=3D
s and cooler glazes. So far I've mixed a ^6 ash glaze and a ^6 Temnoku and =
=3D
found a recipe for one wide firing range ^4-^10 glaze. I'm wondering if it =
=3D
really would give me a safe useful melt. Apparently concocted by Rudy Staff=
=3D
el some time ago and is as follows... =3D0A=3D0A Opalescent Staffel 20 ^4 t=
o ^1=3D
0=3D0A=3D0Apotash spar=3DE2=3D80=3DA6 55.6 (custer or G200)=3D0Awhiting=3DE=
2=3D80=3DA6 18=3D
=3D0Aepk=3DE2=3D80=3DA6 10.3=3D0Asilica=3DE2=3D80=3DA6 30=3D0A=
zinc=3DE2=3D80=3DA6 =3D
10 =3D0A=3D0A The only problem I might have is not enough body vitrifica=
tion=3D
at ^4 with some of my clay but some of the A.R.T. ^10 stoneware I'm using =
=3D
from the class in town might not be as refractory as my mix with porcelain,=
=3D
stoneware, and extra fire clay. My plan is the adjustments I made to the f=
=3D
irebox, side stoke hole placement, and fine tuning the settings will make t=
=3D
he heat go along the top and through the mid settings before exiting the ta=
=3D
il. =3D0A=3D0A I had no problem getting to ^13 in front within 48 hours and=
I t=3D
hink I might have closed the active damper some to soon to hold the heat in=
=3D
instead of leaving it more open and using the chimney cap instead. That mi=
=3D
ght let the front heat migrate toward the tail better too. I don't expect a=
=3D
nyone to imagine what I'm thinking but it helps me to visualize what might =
=3D
happen while I practice firing the Hobagama a couple more times. Suggestion=
=3D
s on the glaze would be appreciated though, so thanks eh.=3D0A=3D0AGary Nav=
arre=3D
=3D0ANavarre Pottery=3D0ANavarre Enterprises=3D0ANorway, Michigan, USA=3D0A=
http://w=3D
ww.NavarrePottery.etsy.com=3D0Ahttp://www.youtube.com/GindaUP=3D0Ahttp://pu=
blic=3D
.fotki.com/GindaUP/=3D0A=3D0A=3D0A
Ron Roy on mon 28 feb 11
Hi Gary,
Looks like it could be a stable glaze - if it's well enough melted - =3D20
I'd say come 7 would be about right for this one. It will probably =3D20
craze but you may be lucky.
I can do one with a lower expansion if you want to try it. Do you have =3D2=
0
any frits? Which ones?
You are right about the cone 10 clay not vitrifying enough at cone 6 =3D20
or 7 - there are enough leaky functional pots in this world already.
RR
Quoting gary navarre :
> Hey Folks,
>
> I've made a decision to use some lower maturing glazes toward the =3D20
> tail of my kiln and am wondering if there are many formulas that =3D20
> make a food safe ^4-^8 or ^10? My plan is to load the under fired =3D20
> ^10 pieces from earlier firings and load the mid-tail and tail =3D20
> settings with fresh pots and cooler glazes. So far I've mixed a ^6 =3D20
> ash glaze and a ^6 Temnoku and found a recipe for one wide firing =3D20
> range ^4-^10 glaze. I'm wondering if it really would give me a safe =3D20
> useful melt. Apparently concocted by Rudy Staffel some time ago and =3D20
> is as follows...
>
> Opalescent Staffel 20 ^4 to ^10
>
> potash spar=3DE2=3D80=3DA6 55.6 (custer or G200)
> whiting=3DE2=3D80=3DA6 18
> epk=3DE2=3D80=3DA6 10.3
> silica=3DE2=3D80=3DA6 30
> zinc=3DE2=3D80=3DA6 10
>
> The only problem I might have is not enough body vitrification at =3D20
> ^4 with some of my clay but some of the A.R.T. ^10 stoneware I'm =3D20
> using from the class in town might not be as refractory as my mix =3D20
> with porcelain, stoneware, and extra fire clay. My plan is the =3D20
> adjustments I made to the firebox, side stoke hole placement, and =3D20
> fine tuning the settings will make the heat go along the top and =3D20
> through the mid settings before exiting the tail.
>
> I had no problem getting to ^13 in front within 48 hours and I =3D20
> think I might have closed the active damper some to soon to hold the =3D2=
0
> heat in instead of leaving it more open and using the chimney cap =3D20
> instead. That might let the front heat migrate toward the tail =3D20
> better too. I don't expect anyone to imagine what I'm thinking but =3D20
> it helps me to visualize what might happen while I practice firing =3D20
> the Hobagama a couple more times. Suggestions on the glaze would be =3D20
> appreciated though, so thanks eh.
>
> Gary Navarre
> Navarre Pottery
> Navarre Enterprises
> Norway, Michigan, USA
> http://www.NavarrePottery.etsy.com
> http://www.youtube.com/GindaUP
> http://public.fotki.com/GindaUP/
>
>
>
>
gary navarre on mon 28 feb 11
Thanks Ron, =3D0A=3D0A That's more about what I'm wondering. My plan is I w=
ill =3D
be able to get the tail up a couple cones but I might as well take advantag=
=3D
e of the smaller space back there now for lower melt glaze tests if I don't=
=3D
. I don't have any frits at home but I do have a sack of Gerstly Borate I s=
=3D
uppose I could use for another flux. =3D0A=3D0A I can try for bodies to mat=
ch l=3D
ater unless I can get the tail to vitrification in the next firing or two. =
=3D
If I still get an under fired body but good glaze melt I can get some boxes=
=3D
of ^4-^6 clay to make the couple dozen pieces that fit in the tail, maybe =
=3D
something different from what I usually make that is less functional. There=
=3D
are lots of products that don't come into contact with food or liquids lik=
=3D
e candle holders, incense burners, and jewelry boxes. =3D0A =3D0AGary Navar=
re=3D
=3D0ANavarre Pottery=3D0ANavarre Enterprises=3D0ANorway, Michigan, USA=3D0A=
http://w=3D
ww.NavarrePottery.etsy.com=3D0Ahttp://www.youtube.com/GindaUP=3D0Ahttp://pu=
blic=3D
.fotki.com/GindaUP/=3D0A=3D0A=3D0A--- On Mon, 2/28/11, ronroy@ca.inter.net =
y@ca.inter.net> wrote:=3D0A=3D0A> From: ronroy@ca.inter.net r.ne=3D
t>=3D0A> Subject: Re: Wide firing range glaze?=3D0A> To: "gary navarre" varr=3D
eenterprises@YAHOO.COM>=3D0A> Cc: Clayart@LSV.CERAMICS.ORG=3D0A> Date: Mond=
ay, =3D
February 28, 2011, 3:53 PM=3D0A> Hi Gary,=3D0A> =3D0A> Looks like it could =
be a s=3D
table glaze - if it's well enough=3D0A> melted - I'd say come 7 would be ab=
ou=3D
t right for this one.=3D0A> It will probably craze but you may be lucky.=3D=
0A> =3D
=3D0A> I can do one with a lower expansion if you want to try it.=3D0A> Do =
you =3D
have any frits? Which ones?=3D0A> =3D0A> =3D0A> You are right about the con=
e 10 c=3D
lay not vitrifying enough=3D0A> at cone 6 or 7 - there are enough leaky fun=
ct=3D
ional pots in=3D0A> this world already.=3D0A> =3D0A> RR=3D0A> =3D0A> =3D0A>=
Quoting gar=3D
y navarre :=3D0A> =3D0A> > Hey Folks,=3D0A> >=
=3D0A> =3D
>=3DC2=3DA0 I've made a decision to use some lower maturing=3D0A> glazes to=
ward t=3D
he tail of my kiln and am wondering if there=3D0A> are many formulas that m=
ak=3D
e a food safe ^4-^8 or ^10? My=3D0A> plan is to load the under fired ^10 pi=
ec=3D
es from earlier=3D0A> firings and load the mid-tail and tail settings with =
fr=3D
esh=3D0A> pots and cooler glazes. So far I've mixed a ^6 ash glaze and=3D0A=
> a =3D
^6 Temnoku and found a recipe for one wide firing range=3D0A> ^4-^10 glaze.=
I=3D
'm wondering if it really would give me a=3D0A> safe useful melt. Apparentl=
y =3D
concocted by Rudy Staffel some=3D0A> time ago and is as follows...=3D0A> > =
=3D0A>=3D
>=3DC2=3DA0 Opalescent Staffel 20 ^4 to ^10=3D0A> > =3D0A> > potash spar=
=3DE2=3D80=3DA6 =3D
55.6 (custer or G200)=3D0A> > whiting=3DE2=3D80=3DA6=3DC2=3DA0 =3DC2=3DA0=
=3DC2=3DA0=3DC2=3DA018=3D0A>=3D
> epk=3DE2=3D80=3DA6=3DC2=3DA0 =3DC2=3DA0 =3DC2=3DA0 =3DC2=3DA0=3DC2=3DA0=
=3DC2=3DA010.3=3D0A> > silica=3DE2=3D
=3D80=3DA6=3DC2=3DA0 =3DC2=3DA0 =3DC2=3DA0 30=3D0A> > zinc=3DE2=3D80=3DA6=
=3DC2=3DA0 =3DC2=3DA0 =3DC2=3DA0 =3DC2=3D
=3DA0 10=3D0A> > =3D0A> >=3DC2=3DA0 The only problem I might have is not en=
ough body=3D
=3D0A> vitrification at ^4 with some of my clay but some of the=3D0A> A.R.T=
. ^1=3D
0 stoneware I'm using from the class in town might=3D0A> not be as refracto=
ry=3D
as my mix with porcelain, stoneware,=3D0A> and extra fire clay. My plan is=
t=3D
he adjustments I made to=3D0A> the firebox, side stoke hole placement, and =
fi=3D
ne tuning the=3D0A> settings will make the heat go along the top and throug=
h =3D
the=3D0A> mid settings before exiting the tail.=3D0A> > =3D0A> >=3DC2=3DA0 =
I had no p=3D
roblem getting to ^13 in front within=3D0A> 48 hours and I think I might ha=
ve=3D
closed the active damper=3D0A> some to soon to hold the heat in instead of=
l=3D
eaving it more=3D0A> open and using the chimney cap instead. That might let=
t=3D
he=3D0A> front heat migrate toward the tail better too. I don't=3D0A> expec=
t an=3D
yone to imagine what I'm thinking but it helps me=3D0A> to visualize what m=
ig=3D
ht happen while I practice firing the=3D0A> Hobagama a couple more times. S=
ug=3D
gestions on the glaze would=3D0A> be appreciated though, so thanks eh.=3D0A=
> > =3D
=3D0A> > Gary Navarre=3D0A> > Navarre Pottery=3D0A> > Navarre Enterprises=
=3D0A> > N=3D
orway, Michigan, USA=3D0A> > http://www.NavarrePottery.etsy.com=3D0A> > htt=
p://=3D
www.youtube.com/GindaUP=3D0A> > http://public.fotki.com/GindaUP/=3D0A> > =
=3D0A> >=3D
=3D0A> > =3D0A> > =3D0A> =3D0A> =3D0A> =3D0A=3D0A=3D0A
Eva Gallagher on tue 1 mar 11
Hi Gary - before my last wood firing I tested some of our cone 10 high fire
glazes from John Britt's book and I was amazed how many worked at cone 6 in
electric. I find that the Ranch Butter is great at cone 6 - smooth and shin=
y
same as at cone 10 - it appears almost identical and it does not craze on
either stoneware or porcelain that I use. I use it as a liner - goes a warm
pale cream on stoneware, whiter on porc.
Other glazes that worked at cone 10 were Currie 10, Hannah Fake Ash, VCA
Blue and green - (this one though a bit more matt), Fraser Celadon (as
revised by RR), etc.. In case you do not have the book I will be glad to
email you the recipes.
Good luck.
Eva Gallagher
Deep River, Ontario
http://newfoundoutpotter.blogspot.com/
http://www.valleyartisans.com/gallagher/Gallagher.htm
----- Original Message -----
From: "gary navarre"
To:
Sent: Monday, February 28, 2011 7:00 PM
Subject: Re: Wide firing range glaze?
Thanks Ron,
That's more about what I'm wondering. My plan is I will be able to get the
tail up a couple cones but I might as well take advantage of the smaller
space back there now for lower melt glaze tests if I don't. I don't have an=
y
frits at home but I do have a sack of Gerstly Borate I suppose I could use
for another flux.
I can try for bodies to match later unless I can get the tail to
vitrification in the next firing or two. If I still get an under fired body
but good glaze melt I can get some boxes of ^4-^6 clay to make the couple
dozen pieces that fit in the tail, maybe something different from what I
usually make that is less functional. There are lots of products that don't
come into contact with food or liquids like candle holders, incense burners=
,
and jewelry boxes.
Gary Navarre
Navarre Pottery
Navarre Enterprises
Norway, Michigan, USA
http://www.NavarrePottery.etsy.com
http://www.youtube.com/GindaUP
http://public.fotki.com/GindaUP/
--- On Mon, 2/28/11, ronroy@ca.inter.net wrote:
> From: ronroy@ca.inter.net
> Subject: Re: Wide firing range glaze?
> To: "gary navarre"
> Cc: Clayart@LSV.CERAMICS.ORG
> Date: Monday, February 28, 2011, 3:53 PM
> Hi Gary,
>
> Looks like it could be a stable glaze - if it's well enough
> melted - I'd say come 7 would be about right for this one.
> It will probably craze but you may be lucky.
>
> I can do one with a lower expansion if you want to try it.
> Do you have any frits? Which ones?
>
>
> You are right about the cone 10 clay not vitrifying enough
> at cone 6 or 7 - there are enough leaky functional pots in
> this world already.
>
> RR
>
>
> Quoting gary navarre :
>
> > Hey Folks,
> >
> > I've made a decision to use some lower maturing
> glazes toward the tail of my kiln and am wondering if there
> are many formulas that make a food safe ^4-^8 or ^10? My
> plan is to load the under fired ^10 pieces from earlier
> firings and load the mid-tail and tail settings with fresh
> pots and cooler glazes. So far I've mixed a ^6 ash glaze and
> a ^6 Temnoku and found a recipe for one wide firing range
> ^4-^10 glaze. I'm wondering if it really would give me a
> safe useful melt. Apparently concocted by Rudy Staffel some
> time ago and is as follows...
> >
> > Opalescent Staffel 20 ^4 to ^10
> >
> > potash spar=E2EUR=A6 55.6 (custer or G200)
> > whiting=E2EUR=A6 18
> > epk=E2EUR=A6 10.3
> > silica=E2EUR=A6 30
> > zinc=E2EUR=A6 10
> >
> > The only problem I might have is not enough body
> vitrification at ^4 with some of my clay but some of the
> A.R.T. ^10 stoneware I'm using from the class in town might
> not be as refractory as my mix with porcelain, stoneware,
> and extra fire clay. My plan is the adjustments I made to
> the firebox, side stoke hole placement, and fine tuning the
> settings will make the heat go along the top and through the
> mid settings before exiting the tail.
> >
> > I had no problem getting to ^13 in front within
> 48 hours and I think I might have closed the active damper
> some to soon to hold the heat in instead of leaving it more
> open and using the chimney cap instead. That might let the
> front heat migrate toward the tail better too. I don't
> expect anyone to imagine what I'm thinking but it helps me
> to visualize what might happen while I practice firing the
> Hobagama a couple more times. Suggestions on the glaze would
> be appreciated though, so thanks eh.
> >
> > Gary Navarre
> > Navarre Pottery
> > Navarre Enterprises
> > Norway, Michigan, USA
> > http://www.NavarrePottery.etsy.com
> > http://www.youtube.com/GindaUP
> > http://public.fotki.com/GindaUP/
> >
> >
> >
> >
>
>
>
Ron Roy on tue 1 mar 11
Hi Gary,
I just thought of something - if you use zinc as a flux in glazes in
reduction it gets reduced to the metal which boils away in most cases.
I suggest using the GB instead - let me know if you want me to make up
a fool proof cone 6 glaze - RR
Quoting gary navarre :
> Thanks Ron,
>
> That's more about what I'm wondering. My plan is I will be able to
> get the tail up a couple cones but I might as well take advantage of
> the smaller space back there now for lower melt glaze tests if I
> don't. I don't have any frits at home but I do have a sack of
> Gerstly Borate I suppose I could use for another flux.
>
> I can try for bodies to match later unless I can get the tail to
> vitrification in the next firing or two. If I still get an under
> fired body but good glaze melt I can get some boxes of ^4-^6 clay to
> make the couple dozen pieces that fit in the tail, maybe something
> different from what I usually make that is less functional. There
> are lots of products that don't come into contact with food or
> liquids like candle holders, incense burners, and jewelry boxes.
gary navarre on wed 2 mar 11
Ya Ron,=3D0A=3D0A Someone else pointed out reduced Zinc bubbling off could =
caus=3D
e pinholing. However, a good long soaking as would happen in my wood kiln w=
=3D
as one solution I read about. Would Gerstly Borate be substituted on an equ=
=3D
al basis? =3D0A=3D0A Since I have Gerstly Borate I'd like to use it as a c=
onve=3D
nient flux and have been wondering what approximate percents would correspo=
=3D
nd to lowering a cone 10+ glaze to a ^8 or ^6, maybe ^4 if I don't get the =
=3D
tail hotter this next firing. Dart gave me a bunch of lower temp cones so I=
=3D
will be putting more cone packs throughout the settings this time. If I kn=
=3D
ow where the heat settles then I could be satisfied with glazes with a 2 co=
=3D
ne range. It might be interesting to take pots from the front and refire th=
=3D
em in another part of the kiln with a different glaze. =3D0A=3D0A Heck ya, =
a co=3D
uple fool proof base glazes with a 3 or 4 cone range and maybe enough clay =
=3D
to be single fired would be great. Seems like so many recipes are designed =
=3D
to be fired within a narrow cone range in computer controlled electrics and=
=3D
a cone and a half low it is dry or a little hot it might slide off. =3D0A=
=3D0A=3D
Thanks for the ideas. I should have learned this stuff years ago but I was=
=3D
never in one place long enough to test things out and put it to good use. =
=3D
Maybe this time around I can really learn something before everything chang=
=3D
es again so I'll stay in there, eh.=3D0A=3D0AGary Navarre=3D0ANavarre Potte=
ry=3D0AN=3D
avarre Enterprises=3D0ANorway, Michigan, USA=3D0Ahttp://www.NavarrePottery.=
etsy=3D
.com=3D0Ahttp://www.youtube.com/GindaUP=3D0Ahttp://public.fotki.com/GindaUP=
/=3D0A=3D
=3D0A=3D0A--- On Tue, 3/1/11, Ron Roy wrote:=3D0A=3D0=
A> From:=3D
Ron Roy =3D0A> Subject: Re: [Clayart] Wide firing ran=
ge=3D
glaze?=3D0A> To: Clayart@LSV.CERAMICS.ORG=3D0A> Date: Tuesday, March 1, 20=
11, =3D
12:08 PM=3D0A> Hi Gary,=3D0A> =3D0A> I just thought of something - if you u=
se zin=3D
c as a flux in=3D0A> glazes in=3D0A> reduction it gets reduced to the metal=
whi=3D
ch boils away in=3D0A> most cases.=3D0A> =3D0A> I suggest using the GB inst=
ead - =3D
let me know if you want me=3D0A> to make up=3D0A> a fool proof cone 6 glaze=
- R=3D
R=3D0A> =3D0A> Quoting gary navarre :=3D0A> =
=3D0A> > =3D
Thanks Ron,=3D0A> >=3D0A> >=3DA0 That's more about what I'm wondering. My p=
lan is=3D
=3D0A> I will be able to=3D0A> > get the tail up a couple cones but I might=
as =3D
well=3D0A> take advantage of=3D0A> > the smaller space back there now for l=
ower=3D
melt glaze=3D0A> tests if I=3D0A> > don't. I don't have any frits at home =
but =3D
I do have a=3D0A> sack of=3D0A> > Gerstly Borate I suppose I could use for =
anot=3D
her=3D0A> flux.=3D0A> >=3D0A> >=3DA0 I can try for bodies to match later un=
less I c=3D
an=3D0A> get the tail to=3D0A> > vitrification in the next firing or two. I=
f I =3D
still=3D0A> get an under=3D0A> > fired body but good glaze melt I can get s=
ome =3D
boxes of=3D0A> ^4-^6 clay to=3D0A> > make the couple dozen pieces that fit =
in t=3D
he tail,=3D0A> maybe something=3D0A> > different from what I usually make t=
hat =3D
is less=3D0A> functional. There=3D0A> > are lots of products that don't com=
e in=3D
to contact with=3D0A> food or=3D0A> > liquids like candle holders, incense =
burn=3D
ers, and=3D0A> jewelry boxes.=3D0A> =3D0A=3D0A=3D0A
gary navarre on wed 2 mar 11
Ya Eva, Thanks, that would be great. I'm starting to wish I'd have bought a=
few of those newer books when I had a real job a while back but I think I =
was to obsessed with kiln building. Now I need to come up with over a grand=
to get the van fixed. Gee I wish I didn't have to depend on a vehicle. I'v=
e never liked it.
Gary Navarre
Navarre Pottery
Navarre Enterprises
Norway, Michigan, USA
http://www.NavarrePottery.etsy.com
http://www.youtube.com/GindaUP
http://public.fotki.com/GindaUP/
--- On Tue, 3/1/11, Eva Gallagher wrote:
> From: Eva Gallagher
> Subject: Re: [Clayart] Wide firing range glaze?
> To: Clayart@LSV.CERAMICS.ORG
> Date: Tuesday, March 1, 2011, 8:32 PM
> Hi Gary - before my last wood firing
> I tested some of our cone 10 high fire
> glazes from John Britt's book and I was amazed how many
> worked at cone 6 in
> electric. I find that the Ranch Butter is great at cone 6 -
> smooth and shiny
> same as at cone 10 - it appears almost identical and it
> does not craze on
> either stoneware or porcelain that I use. I use it as a
> liner - goes a warm
> pale cream on stoneware, whiter on porc.
> Other glazes that worked at cone 10 were Currie 10, Hannah
> Fake Ash, VCA
> Blue and green - (this one though a bit more matt), Fraser
> Celadon (as
> revised by RR), etc.. In case you do not have the book I
> will be glad to
> email you the recipes.
> Good luck.
> Eva Gallagher
> Deep River, Ontario
> http://newfoundoutpotter.blogspot.com/
> http://www.valleyartisans.com/gallagher/Gallagher.htm
Eva Gallagher on thu 3 mar 11
Hi Gary - here are the recipes of some of the cone 10 glazes from John
Britt's book that worked at cone 6. I also tested some with ashes sprinkled
on them to see how they would react to the ashes in the wood kiln but now I
can't find those notes.
Ranch Butter - cones 6-10, shiny white (ox) to cream (redux) though book
shows it as more of a matt.
Custer 36.3
Silica 25.4
Whiting 8
Talc 6
Kaolin 5
Gert Bor 13
Zircopax 14.9
Probably could reduce the zircopax and still get white. Does not craze on
either porc or stoneware. Seems to me that it was OK with ashes on it
otherwise I would not have used so much of it on my wood firing - I used it
as a liner on cups etc.
Currie 10 - a teadust recipe - cone 6 - 10 not sure about the crystals in
oxidation or at cone 6. Ashes tend to bleach out the iron.
Custer 50.3
Silica 22.2
whiting 16.6
Kaolin 7.1
Magnesium carbonate 3.8
Red iron 8
Bailey's Red - an iron red - cone 6 -10 - not sure about the red in ox - bu=
t
could get some with the slow cool. really great at cone 10 with a slow cool=
.
Not sure of effect of ashes.
Custer 47
Silica 13
Kaolin 13
Talc 10.5
Bone ash 14
Lithium carbonate 2.5
Red iron oxide 8
VCAA Blue Green - cone 6 (more matt) than at cone 10
Cornwall stone - 46
Whiting 34
Kaolin 20
Copper carbonate - 4
Tin oxide 4
Hannah Ash - great at cone 6 or 10 - tends to run more at 10. In oxidation
at cone 6 the yellow version is a nice yellowish colour on white clay. Not
from Britt's book but I think one of Steven Hill's glazes that was publishe=
d
somewhere.
Red art clay 60
Whiting 30
Strontium carbonate 10
For yellow add 4% yellow ochre
For blue add 1.5% cobalt carbonate
These glazes reacted nicely with the ashes in the wood kiln.
Also the Fraser celadon as revised by Ron Roy to prevent crazing works well
from cone 6 to 10 but I don't have the recipe here.
Hope this helps and good luck.
Eva Gallagher
Deep River, Ontario
http://newfoundoutpotter.blogspot.com/
http://www.valleyartisans.com/gallagher/Gallagher.htm
----- Original Message -----
From: "gary navarre"
To:
Sent: Thursday, March 03, 2011 12:39 AM
Subject: Re: Wide firing range glaze?
> Ya Eva, Thanks, that would be great. I'm starting to wish I'd have bought
> a few of those newer books when I had a real job a while back but I think
> I was to obsessed with kiln building. Now I need to come up with over a
> grand to get the van fixed. Gee I wish I didn't have to depend on a
> vehicle. I've never liked it.
>
> Gary Navarre
> Navarre Pottery
> Navarre Enterprises
> Norway, Michigan, USA
> http://www.NavarrePottery.etsy.com
> http://www.youtube.com/GindaUP
> http://public.fotki.com/GindaUP/
>
>
> --- On Tue, 3/1/11, Eva Gallagher wrote:
>
>> From: Eva Gallagher
>> Subject: Re: [Clayart] Wide firing range glaze?
>> To: Clayart@LSV.CERAMICS.ORG
>> Date: Tuesday, March 1, 2011, 8:32 PM
>> Hi Gary - before my last wood firing
>> I tested some of our cone 10 high fire
>> glazes from John Britt's book and I was amazed how many
>> worked at cone 6 in
>> electric. I find that the Ranch Butter is great at cone 6 -
>> smooth and shiny
>> same as at cone 10 - it appears almost identical and it
>> does not craze on
>> either stoneware or porcelain that I use. I use it as a
>> liner - goes a warm
>> pale cream on stoneware, whiter on porc.
>> Other glazes that worked at cone 10 were Currie 10, Hannah
>> Fake Ash, VCA
>> Blue and green - (this one though a bit more matt), Fraser
>> Celadon (as
>> revised by RR), etc.. In case you do not have the book I
>> will be glad to
>> email you the recipes.
>> Good luck.
>> Eva Gallagher
>> Deep River, Ontario
>> http://newfoundoutpotter.blogspot.com/
>> http://www.valleyartisans.com/gallagher/Gallagher.htm
>
>
gary navarre on thu 3 mar 11
Thanks Ron,=3D0A=3D0A I'll try this too. It looks like there is enough clay=
for=3D
single fire.=3D0A=3D0AGary Navarre=3D0ANavarre Pottery=3D0ANavarre Enterpr=
ises=3D0AN=3D
orway, Michigan, USA=3D0Ahttp://www.NavarrePottery.etsy.com=3D0Ahttp://www.=
yout=3D
ube.com/GindaUP=3D0Ahttp://public.fotki.com/GindaUP/=3D0A=3D0A=3D0A--- On T=
hu, 3/3/=3D
11, ronroy@ca.inter.net wrote:=3D0A=3D0A> From: ronro=
y@ca=3D
.inter.net =3D0A> Subject: Re: [Clayart] Wide firing r=
an=3D
ge glaze?=3D0A> To: "gary navarre" =3D0A> Cc:=
Cla=3D
yart@LSV.CERAMICS.ORG=3D0A> Date: Thursday, March 3, 2011, 2:33 PM=3D0A> Hi=
Gar=3D
y,=3D0A> =3D0A> Not only does the zinc cause pinholing in some cases but -=
=3D0A> =3D
when reduction starts thats when it's reduced to the metal -=3D0A> which bo=
il=3D
s at 800C - the result can be no low fire flux=3D0A> left in the glaze so i=
t =3D
won't melt.=3D0A> =3D0A> Here is a well balanced glaze - won't craze on mos=
t cl=3D
ays=3D0A> and will probably be OK from cone 6 to cone 8 - you will=3D0A> ha=
ve t=3D
o test though.=3D0A> =3D0A> Add 10% zircopax or other zirconium silicate li=
ke s=3D
uperpax=3D0A> to get a white for a good functional liner glaze. 5% tin=3D0A=
> wi=3D
ll get a warmer white but you won't like the price of tin=3D0A> oxide.=3D0A=
> =3D
=3D0A> Spread some test tiles around but make em do any running=3D0A> will =
not =3D
reach a shelf. Good to have some cones near them so=3D0A> you can figurer o=
ut=3D
what the right range of the glaze will=3D0A> be.=3D0A> =3D0A> =3D0A> =3DA0=
CUSTER SP=3D
AR.................=3DA0 =3DA0=3D0A> 18.00=3DA0 (can use G200 or G200HP)=3D=
0A> =3DA0 WH=3D
ITING.....................=3DA0=3D0A> =3DA0=3DA0=3DA07.00=3D0A> =3DA0 DOLOM=
ITE...........=3D
.........=3DA0=3D0A> =3DA0=3DA0=3DA06.00=3D0A> =3DA0 GERS BORATE 9/97......=
......=3DA0 =3DA0 =3D
20.00=3D0A> =3DA0 OM-4........................=3DA0 =3DA0 24.00=3D0A> =3DA0=
SILICA.....=3D
.................=3DA0 =3DA0 25.00=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA=
0 =3DA0 =3DA0=3D0A> =3DA0 =3D
=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3=
D=3D3D=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0=3D
=3DA0 =3DA0 =3DA0=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0=3D0A> =
=3DA0=3DA0=3DA0100.00=3D0A> =3D0A> =3D
=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 CaO=3DA0 =3DA0=3D0A> =3DA0=3DA0=3DA00.63*=3DA=
0=3DA0=3DA011.38=3D0A> =3DA0 =3DA0=3D
=3DA0 =3DA0 =3DA0 MgO=3DA0 =3DA0=3D0A> =3DA0=3DA0=3DA00.20*=3DA0 =3DA0 2.5=
8=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3D
=3DA0 K2O=3DA0 =3DA0=3D0A> =3DA0=3DA0=3DA00.09*=3DA0 =3DA0 2.75=3D0A> =3DA0=
=3DA0 =3DA0 =3DA0 =3DA0 Na2O=3D
=3DA0 =3DA0 =3DA0=3D0A> 0.09*=3DA0 =3DA0 1.74=3D0A> =3DA0 =3DA0 =3DA0 =3DA0=
=3DA0 Fe2O3=3DA0=3D0A> =3DA0=3D
=3DA0=3DA00.01=3DA0 =3DA0=3DA0=3DA00.52=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0=
TiO2=3DA0 =3DA0 =3DA0=3D0A> 0.0=3D
1=3DA0 =3DA0=3DA0=3DA00.34=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 B2O3=3DA0 =
=3DA0 =3DA0=3D0A> 0.29=3DA0 =3DA0=3D
=3DA0=3DA06.51=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 Al2O3=3DA0=3D0A> =3DA0=
=3DA0=3DA00.36=3DA0 =3DA0 11.93=3D
=3D0A> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 SiO2=3DA0 =3DA0 =3DA0=3D0A> 3.20=3DA0 =
=3DA0 62.25=3D0A> =3D0A> =3DA0=3D
=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0=3D0A> =3DA0 =3DA0 =3DA0=3DA0=3DA=
0Si:Al:=3DA0 =3DA0 8.87=3D0A> =3D
=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0=3D0A> =3DA0 =3DA0 =3DA0 SiB=
:Al:=3DA0 =3DA0 9.67=3D0A> =3DA0=3D
=3DA0 =3DA0 =3DA0 =3DA0=3DA0=3DA0Thermal=3D0A> Expansion:=3DA0 390.73=3D0A=
> =3DA0 =3DA0 =3DA0 =3DA0 =3D
=3DA0 =3DA0 =3DA0 Formula=3D0A> Weight:=3DA0 308.50=3D0A> =3D0A> R> =3D0A=
=3D0A=3D0A
Ron Roy on thu 3 mar 11
Hi Gary,
Not only does the zinc cause pinholing in some cases but - when
reduction starts thats when it's reduced to the metal - which boils at
800C - the result can be no low fire flux left in the glaze so it
won't melt.
Here is a well balanced glaze - won't craze on most clays and will
probably be OK from cone 6 to cone 8 - you will have to test though.
Add 10% zircopax or other zirconium silicate like superpax to get a
white for a good functional liner glaze. 5% tin will get a warmer
white but you won't like the price of tin oxide.
Spread some test tiles around but make em do any running will not
reach a shelf. Good to have some cones near them so you can figurer
out what the right range of the glaze will be.
CUSTER SPAR................. 18.00 (can use G200 or G200HP)
WHITING..................... 7.00
DOLOMITE.................... 6.00
GERS BORATE 9/97............ 20.00
OM-4........................ 24.00
SILICA...................... 25.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00
CaO 0.63* 11.38
MgO 0.20* 2.58
K2O 0.09* 2.75
Na2O 0.09* 1.74
Fe2O3 0.01 0.52
TiO2 0.01 0.34
B2O3 0.29 6.51
Al2O3 0.36 11.93
SiO2 3.20 62.25
Si:Al: 8.87
SiB:Al: 9.67
Thermal Expansion: 390.73
Formula Weight: 308.50
R
Quoting gary navarre :
> Ya Ron,
>
> Someone else pointed out reduced Zinc bubbling off could cause
> pinholing. However, a good long soaking as would happen in my wood
> kiln was one solution I read about. Would Gerstly Borate be
> substituted on an equal basis?
>
> Since I have Gerstly Borate I'd like to use it as a convenient flux
> and have been wondering what approximate percents would correspond
> to lowering a cone 10+ glaze to a ^8 or ^6, maybe ^4 if I don't get
> the tail hotter this next firing. Dart gave me a bunch of lower temp
> cones so I will be putting more cone packs throughout the settings
> this time. If I know where the heat settles then I could be
> satisfied with glazes with a 2 cone range. It might be interesting
> to take pots from the front and refire them in another part of the
> kiln with a different glaze.
>
> Heck ya, a couple fool proof base glazes with a 3 or 4 cone range
> and maybe enough clay to be single fired would be great. Seems like
> so many recipes are designed to be fired within a narrow cone range
> in computer controlled electrics and a cone and a half low it is dry
> or a little hot it might slide off.
>
> Thanks for the ideas. I should have learned this stuff years ago
> but I was never in one place long enough to test things out and put
> it to good use. Maybe this time around I can really learn something
> before everything changes again so I'll stay in there, eh.
gary navarre on fri 4 mar 11
Hey Ron,=3D0A=3D0A Are you certain about zinc boiling at 800=3DB0C in relat=
ion to=3D
when reduction starts (must be a typo eh). I try to fire oxidation to at l=
=3D
east 1000=3DB0C (1832=3DB0F) or ^07-^06 Orton using Cardews recommendation =
on u=3D
sing a Bourry box. In the temperature chart in appendix 14 of Pioneer Potte=
=3D
ry it says zinc boils at 907=3DB0C (1664.6=3DB0F) which is actually closer =
to w=3D
hen I start reduction than 800=3DB0C. Either way, could it be supposed that=
t=3D
he zinc would still have a chance to preform it's fluxing action as long as=
=3D
I could keep that part of the chamber in oxidation until ^06?=3D0AI'm look=
in=3D
g at my firing records and the tail remained slightly hotter than the front=
=3D
until around 500=3DB0F at which point the balance starts tipping toward th=
e =3D
front being hotter until it is about 1425=3DB0F in front and 1000=3DB0F in =
the =3D
tail with little smoke. That could change since I made adjustments to the f=
=3D
irebox and setting pattern so I'm gonna have a go at firing some of the pie=
=3D
ces with this ^4-^10 in the tail and mid-tail settings along with a few oth=
=3D
er recommendations from some other folks. I only mixed 1200g split in three=
=3D
with one clear, one .0025% cobalt, and the third 1% copper carb and 4% rut=
=3D
ile so it's not that expensive to do a test and maybe get lucky. At least I=
=3D
'll have a good example of the pin holing and understand the cause. The mid=
=3D
-front and front settings will have the re-fires from the mid and tail sett=
=3D
ings of the first two firings with no reglazing.=3D0A=3D0A So thanks a lot =
folk=3D
s. I'm gonna try another couple recipes so I need to look in the shed for a=
=3D
box of talc I think I saw after unloading that old home built Internationa=
=3D
l pickup box trailer I usta have for moving. =3D0A=3D0A Stay in there eh.=
=3D0A =3D
=3D0AGary Navarre=3D0ANavarre Pottery=3D0ANavarre Enterprises=3D0ANorway=
, Michig=3D
an, USA=3D0Ahttp://www.NavarrePottery.etsy.com=3D0Ahttp://www.youtube.com/G=
inda=3D
UP=3D0Ahttp://public.fotki.com/GindaUP/=3D0A=3D0A=3D0A--- On Thu, 3/3/11, R=
on Roy <=3D
ronroy@CA.INTER.NET> wrote:=3D0A=3D0A> From: Ron Roy =
=3D0A> =3D
Subject: Re: [Clayart] Wide firing range glaze?=3D0A> To: Clayart@LSV.CERAM=
IC=3D
S.ORG=3D0A> Date: Thursday, March 3, 2011, 2:33 PM=3D0A> Hi Gary,=3D0A> =3D=
0A> Not =3D
only does the zinc cause pinholing in some cases but -=3D0A> when=3D0A> red=
ucti=3D
on starts thats when it's reduced to the metal -=3D0A> which boils at=3D0A>=
800=3D
C - the result can be no low fire flux left in the glaze=3D0A> so it=3D0A> =
won'=3D
t melt.=3D0A> =3D0A> R=3D0A=3D0A=3D0A=3D0A
Ron Roy on sat 5 mar 11
Hi Gary,
You are right - Hamer says 925C - I was being lazy about looking it =3D20
up. It is not a flux till almost 1100 so it will not be there when you =3D2=
0
need it. It is very easily reduced and that can lead to pin holing =3D20
even in cone 6 electric when there is some burning of organics going on.
David Hendly did an article in CM on zinc in copper reds and found out =3D2=
0
that it was not necessary in most of them because the glazes worked =3D20
the same without it.
Let me know how that glaze works out - RR
Quoting gary navarre :
> Hey Ron,
>
> Are you certain about zinc boiling at 800=3DB0C in relation to when =3D2=
0
> reduction starts (must be a typo eh). I try to fire oxidation to at =3D20
> least 1000=3DB0C (1832=3DB0F) or ^07-^06 Orton using Cardews recommendati=
on =3D
=3D20
> on using a Bourry box. In the temperature chart in appendix 14 of =3D20
> Pioneer Pottery it says zinc boils at 907=3DB0C (1664.6=3DB0F) which is =
=3D20
> actually closer to when I start reduction than 800=3DB0C. Either way, =3D=
20
> could it be supposed that the zinc would still have a chance to =3D20
> preform it's fluxing action as long as I could keep that part of the =3D2=
0
> chamber in oxidation until ^06?
> I'm looking at my firing records and the tail remained slightly =3D20
> hotter than the front until around 500=3DB0F at which point the balance =
=3D20
> starts tipping toward the front being hotter until it is about =3D20
> 1425=3DB0F in front and 1000=3DB0F in the tail with little smoke. That co=
uld =3D
=3D20
> change since I made adjustments to the firebox and setting pattern =3D20
> so I'm gonna have a go at firing some of the pieces with this ^4-^10 =3D2=
0
> in the tail and mid-tail settings along with a few other =3D20
> recommendations from some other folks. I only mixed 1200g split in =3D20
> three with one clear, one .0025% cobalt, and the third 1% copper =3D20
> carb and 4% rutile so it's not that expensive to do a test and maybe =3D2=
0
> get lucky. At least I'll have a good example of the pin holing and =3D20
> understand the cause. The mid-front and front settings will have the =3D2=
0
> re-fires from the mid and tail settings of the first two firings =3D20
> with no reglazing.
ivor and olive lewis on sun 6 mar 11
Dear Gary Navarre,
Yes, Cardew does record the Boiling point of Zinc as 907 deg C. But he fail=
s
to add, over the page, that Zinc Oxide melts at 1975 deg C (See CRC Handboo=
k
of Chemistry and Physics for a comprehensive list of chemical properties,
ISBN 0-8493-0477-6.
Regardless of the degree to which you fire in oxidation the metal will not
escape from your glaze because Zinc Oxide does not decompose in the presenc=
e
of Oxygen. But as soon as you introduce an excess of fuel into your kiln,
even if this is at the maturity point of your glaze, the Zinc Oxide will
decompose releasing Zinc metal as a vapour.
Other people may consider my views about the Fluxing activity of Zinc Oxide
and the oxides of Group Two Alkali Metal oxides to be controversial. It is
my opinion that they do not contribute directly to promote an initial
sintering or melting event. But it is illogical to claim these refractory
compounds promote fusion when Silica and Clay, both potential glaze
ingredients whose melting points are much lower, are not so regarded.
I hope your trials are successful.
Sincere regards,
Ivor Lewis,
REDHILL,
South Australia
John Hesselberth on sun 6 mar 11
On Mar 5, 2011, at 11:57 PM, ivor and olive lewis wrote:
> Regardless of the degree to which you fire in oxidation the metal will =
=3D
not
> escape from your glaze because Zinc Oxide does not decompose in the =3D
presence
> of Oxygen. But as soon as you introduce an excess of fuel into your =3D
kiln,
> even if this is at the maturity point of your glaze, the Zinc Oxide =3D
will
> decompose releasing Zinc metal as a vapour.
Hello Ivor,
I think this depend on the degree of melting achieved before you start =3D
reduction. For example, if the glaze is well melted you no longer have =3D
simple chemistry to consider, but rather mass transfer + chemistry. In =3D
other words the reducing specie has to first get at the zinc and mass =3D
transfer processes can be very slow especially in viscous liquids where =3D
diffusion is probably controlling. This explains, for me, why David =3D
Hendley's published experiments (CM a few years back? is that correct =3D
David?) using zinc oxide in reduction showed it was an effective =3D
ingredient in some glaze recipes and not in others.
Regards,
John
ivor and olive lewis on thu 10 mar 11
I have been having a look at Copper and Zinc oxides and their chemistries.
One interesting fact is that metallic Zinc , like Aluminium metal, can act
as a strong reducing agent. Just as Aluminium will reduce Iron oxide to
molten metal under the guise of the Thermite reaction, metallic Zinc can
reduce Copper oxide to metallic Copper.
Please, does anyone have the volume and year for the CM article by David
Hendly. I would like to read his article.
Best regards,
Ivor Lewis,
REDHILL,
South Australia
C Sullivan on fri 11 mar 11
Mornin' Folks
So Ivor -- what is the difference between the Zinc oxide we use in our
recipes and "metallic Zinc" ?
This piques my curiosity . . . .
Hugs
On Wed, Mar 9, 2011 at 11:17 PM, ivor and olive lewis u
> wrote:
> I have been having a look at Copper and Zinc oxides and their chemistries=
.
> One interesting fact is that metallic Zinc , like Aluminium metal, can ac=
t
> as a strong reducing agent. Just as Aluminium will reduce Iron oxide to
> molten metal under the guise of the Thermite reaction, metallic Zinc can
> reduce Copper oxide to metallic Copper.
> Please, does anyone have the volume and year for the CM article by David
> Hendly. I would like to read his article.
> Best regards,
> Ivor Lewis,
> REDHILL,
> South Australia
>
ivor and olive lewis on sat 12 mar 11
Dear C. Sullivan,
Metallic Zinc is what you get when all the oxygen is removed from our
ordinary white powdery Zinc Oxide.
I deliberately used the term "Metallic Zinc" so that there could be no
mental confusion in the minds of artistic potters.
When you play around with this idea of introducing metallic Zinc powder in =
a
glaze containing Copper oxide the system just might work in the same way as
additions of Silicon Carbide into a copper glaze that may be fired in an
electric kiln without needing a reducing atmosphere.
Which is something for the glaze experts to think about
F.W. Berk were, and may still be, manufacturers of minus 200 mesh Zinc
99.99% pure.
Hope that quells your curiosity because it is a brand new idea in Clayart
Land.
Sincere regards,
Ivor.
Ivor Lewis,
REDHILL,
South Australia
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