John Britt on fri 11 may 12
There is a great article in Ceramic Review July /August 2010 on silicon=3D2=
0=3D
carbide electric reds by Mike Bailey. He lays it all out.
Ed's Red cone 10
53 Soda Feldspar
17 Silica
15 Whiting
6 EPK
4 Talc
5 Zinc Oxide
0.5 Copper carbonate=3D20
0.3 Silicon Carbide F1200
1.0 Tin oxide
=3D20=3D20
He varied the firing temp, thickness, type of silicon carbide and tin. It=
=3D
is=3D20
all there!
I have not tried this but would probably just try some standard copper=3D20=
=3D
red recipes with SiC added. (There is no Gerstley borate or frits in the=
=3D
=3D20
recipe above, which strikes me a weird??)
John Britt Pottery
Ben Morrison on sat 12 may 12
________________________________=3D
Wouldn't that craze like crazy?=3D0A=3D0A=3D0A=3D0A________________________=
________=3D
=3D0A From: John Britt =3D0ATo: Clayart@LSV.CER=
AMIC=3D
S.ORG =3D0ASent: Friday, May 11, 2012 4:52 PM=3D0ASubject: Re: SiC electric=
red=3D
=3D0A =3D0AThere is a great article in Ceramic Review July /August 2010 on =
sili=3D
con =3D0Acarbide electric reds by Mike Bailey.=3DA0 He lays it all out.=3D0=
A=3D0AEd=3D
's Red cone 10=3D0A=3D0A53 Soda Feldspar=3D0A17 Silica=3D0A15 Whiting=3D0A6=
=3DA0 EPK=3D0A=3D
4=3DA0 Talc=3D0A5=3DA0 Zinc Oxide=3D0A=3D0A0.5 Copper carbonate =3D0A0.3 Si=
licon Carbid=3D
e F1200=3D0A1.0 Tin oxide=3D0A=3DA0 =3D0A=3D0AHe varied the firing temp, th=
ickness, t=3D
ype of silicon carbide and tin. It is =3D0Aall there!=3D0A=3D0AI have not t=
ried t=3D
his but would probably just try some standard copper =3D0Ared recipes with =
Si=3D
C added.=3DA0 (There is no Gerstley borate or frits in the =3D0Arecipe abov=
e, w=3D
hich strikes me a weird??)=3D0A=3D0AJohn Britt Pottery
Steve Mills on sat 12 may 12
John,=3D20
If you look at most of the recipes that have their origins this side of the=
p=3D
ond you will see a lot of that "weird-ness". We didn't have Gerstley availa=
b=3D
le to us for years, and some Frits can be pretty expensive, so Potters this=
s=3D
ide have learnt to do without them in their recipes.=3D20
The glazes still work and work well!
Try them!
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod
On 12 May 2012, at 00:52, John Britt wrote:
. (There is no Gerstley borate or frits in the=3D20
> recipe above, which strikes me a weird??)
>=3D20
> John Britt Pottery
Ben Morrison on sun 13 may 12
Well I'm probably off base concerning the vast majority of glaze recipes. N=
=3D
one of the ones I use currently leach anything to an extent that would make=
=3D
them unsafe for ware. Most of them have things much more toxic than Zinc. =
=3D
I only mentioned it because I do have a few friends that have overdosed on =
=3D
Zinc, because they did not realize it is insoluble in water. I do have some=
=3D
Zinc recipes, but don't use them in my studio currently. Mastering Cone 6 =
=3D
Glazes by John Hesselberth and Ron Roy has a section that discusses some ve=
=3D
ry nice cone 6 zinc glazes. =3D0A=3D0A=3D0A=3D0A___________________________=
_____=3D0A=3D
From: Robert Harris =3D0ATo: Clayart@LSV.CERAMICS=
.O=3D
RG =3D0ASent: Sunday, May 13, 2012 7:40 PM=3D0ASubject: Re: SiC electric re=
d=3D0A=3D
=3D0AConsidering the fact that Zinc is a necessary element that people tak=
e=3D
=3D0Aas supplements (espercially to combat colds) I'm not sure this is a=3D=
0Agr=3D
eat argument. Also consider that people smear it all over their=3D0Afaces e=
ve=3D
ry summer without the FDA getting too worried. Anyway, as far=3D0Aas I am a=
wa=3D
re Zinc Silicate (which forms on cooling), is pretty damn=3D0Ainsoluble.=3D=
0A=3D
=3D0AUsually glazes from the UK only contain 1-5% Zinc Oxide when it is=3D0=
Abei=3D
ng used as a flux, rather than to form crystals.=3D0A=3D0AAccording to Edou=
ard =3D
Bastarache there is no known evidence of chronic=3D0AZinc toxicity (from th=
e =3D
digitalfire website) which is the only thing=3D0Awe'd worry about. While th=
e =3D
halflife of zinc in the body is 300 days=3D0A(long!), we excrete more than =
80=3D
% of zinc compounds that are ingested=3D0A- hence the need for zinc supplem=
en=3D
ts. Just off the top of my head I=3D0Acan think of several classes of prote=
in=3D
s (with many many members of=3D0Aeach class), that zinc is absolutely requi=
re=3D
d for.=3D0A=3D0ARobert=3D0A=3D0AOn Sun, May 13, 2012 at 9:59 PM, Ben Morris=
on erpdx@yahoo.com> wrote:=3D0A> Zinc is fat soluble, so if it's in an unstabl=
e =3D
glaze it could build up in=3D0A> the body of a person using zinc ware. In a=
s=3D
table base there is no concern.=3D0A> Boron glazes wouldn't have the proble=
m,=3D
which is probably why it's a more=3D0A> desirable material in the US to lo=
we=3D
r the temp of glazes.=3D0A>=3D0A> -Ben=3D0A>=3D0A> ________________________=
________=3D
=3D0A> From: Robert Harris =3D0A> To: Clayart@LSV.=
CERA=3D
MICS.ORG=3D0A> Sent: Saturday, May 12, 2012 9:06 PM=3D0A>=3D0A> Subject: Re=
: SiC =3D
electric red=3D0A>=3D0A> I would say that when I came to the US side of the=
pon=3D
d I thought it=3D0A> was weird that no-one (+/-) used Zinc Oxide in their e=
le=3D
ctric kiln=3D0A> recipes.=3D0A>=3D0A> I would say, at least from my point o=
f view=3D
, people in the UK used=3D0A> Zinc Oxide to lower their fusion temp, where =
th=3D
e US used Boron. I=3D0A> often wonder if this was a holdover from the "Bris=
to=3D
l Glazes" which I=3D0A> believe first replaced lead with zinc when it was r=
ec=3D
ognised that lead=3D0A> was toxic in late Victorian times.=3D0A>=3D0A> Stev=
e I'm =3D
sure has been in the business a lot longer than I have - do=3D0A> you think=
t=3D
hat we in the UK used Zinc Oxide a lot more than the US=3D0A> potters?=3D0A=
>=3D0A=3D
> Robert=3D0A>=3D0A> On Sat, May 12, 2012 at 6:31 PM, Steve Mills=3D0A> iginal=3D
.mudslinger@gmail.com> wrote:=3D0A>> John,=3D0A>> If you look at most of th=
e re=3D
cipes that have their origins this side of=3D0A>> the pond you will see a l=
ot=3D
of that "weird-ness". We didn't have Gerstley=3D0A>> available to us for y=
ea=3D
rs, and some Frits can be pretty expensive, so=3D0A>> Potters this side hav=
e =3D
learnt to do without them in their recipes.=3D0A>> The glazes still work an=
d =3D
work well!=3D0A>> Try them!=3D0A>>=3D0A>> Steve M=3D0A>>=3D0A>> Steve Mills=
=3D0A>> Bath=3D
=3D0A>> UK=3D0A>> www.mudslinger.me.uk=3D0A>> Sent from my iPod=3D0A>>=3D0A=
>>=3D0A>> On=3D
12 May 2012, at 00:52, John Britt wrote:=3D0A=
>>=3D
. =3DA0(There is no Gerstley borate or frits in the=3D0A>>> recipe above, =
whic=3D
h strikes me a weird??)=3D0A>>>=3D0A>>> John Britt Pottery=3D0A>=3D0A>=3D0A=
>=3D0A> --=3D
=3D0A> ----------------------------------------------------------=3D0A>=3D0=
A>=3D0A=3D
=3D0A=3D0A=3D0A-- =3D0A----------------------------------------------------=
------
Robert Harris on sun 13 may 12
I would also add that from my small experience of other UK potters,
electric firing in the UK is done between 1250-1265C (2282F - 2310F).
Which is basically more like Cone 8-9 rather than Cone 6 (which seems
to be the common "standard" in the US). Obviously this reduces the
necessity for Gerstley Borate.
(Again Steve, I'd be interested in your input).
Robert
On Sun, May 13, 2012 at 12:06 AM, Robert Harris w=
=3D
rote:
> I would say that when I came to the US side of the pond I thought it
> was weird that no-one (+/-) used Zinc Oxide in their electric kiln
> recipes.
>
> I would say, at least from my point of view, people in the UK used
> Zinc Oxide to lower their fusion temp, where the US used Boron. I
> often wonder if this was a holdover from the "Bristol Glazes" which I
> believe first replaced lead with zinc when it was recognised that lead
> was toxic in late Victorian times.
>
> Steve I'm sure has been in the business a lot longer than I have - do
> you think that we in the UK used Zinc Oxide a lot more than the US
> potters?
>
> Robert
>
> On Sat, May 12, 2012 at 6:31 PM, Steve Mills
> wrote:
>> John,
>> If you look at most of the recipes that have their origins this side of =
=3D
the pond you will see a lot of that "weird-ness". We didn't have Gerstley a=
=3D
vailable to us for years, and some Frits can be pretty expensive, so Potter=
=3D
s this side have learnt to do without them in their recipes.
>> The glazes still work and work well!
>> Try them!
>>
>> Steve M
>>
>> Steve Mills
>> Bath
>> UK
>> www.mudslinger.me.uk
>> Sent from my iPod
>>
>>
>> On 12 May 2012, at 00:52, John Britt wrote:
>> . =3DA0(There is no Gerstley borate or frits in the
>>> recipe above, which strikes me a weird??)
>>>
>>> John Britt Pottery
>
>
>
> --
> ----------------------------------------------------------
--=3D20
----------------------------------------------------------
Robert Harris on sun 13 may 12
I would say that when I came to the US side of the pond I thought it
was weird that no-one (+/-) used Zinc Oxide in their electric kiln
recipes.
I would say, at least from my point of view, people in the UK used
Zinc Oxide to lower their fusion temp, where the US used Boron. I
often wonder if this was a holdover from the "Bristol Glazes" which I
believe first replaced lead with zinc when it was recognised that lead
was toxic in late Victorian times.
Steve I'm sure has been in the business a lot longer than I have - do
you think that we in the UK used Zinc Oxide a lot more than the US
potters?
Robert
On Sat, May 12, 2012 at 6:31 PM, Steve Mills
wrote:
> John,
> If you look at most of the recipes that have their origins this side of t=
=3D
he pond you will see a lot of that "weird-ness". We didn't have Gerstley av=
=3D
ailable to us for years, and some Frits can be pretty expensive, so Potters=
=3D
this side have learnt to do without them in their recipes.
> The glazes still work and work well!
> Try them!
>
> Steve M
>
> Steve Mills
> Bath
> UK
> www.mudslinger.me.uk
> Sent from my iPod
>
>
> On 12 May 2012, at 00:52, John Britt wrote:
> . =3DA0(There is no Gerstley borate or frits in the
>> recipe above, which strikes me a weird??)
>>
>> John Britt Pottery
--=3D20
----------------------------------------------------------
Ben Morrison on sun 13 may 12
Zinc is fat soluble, so if it's in an unstable glaze it could build up in t=
=3D
he body of a person using zinc ware. In a stable base there is no concern. =
=3D
Boron glazes wouldn't have the problem, which is probably why it's a more d=
=3D
esirable material in the US to lower the temp of glazes.=3DA0=3D0A=3D0A-Ben=
=3D0A=3D0A=3D
=3D0A=3D0A________________________________=3D0A From: Robert Harris gharri=3D
s@GMAIL.COM>=3D0ATo: Clayart@LSV.CERAMICS.ORG =3D0ASent: Saturday, May 12, =
2012=3D
9:06 PM=3D0ASubject: Re: SiC electric red=3D0A =3D0AI would say that when =
I came=3D
to the US side of the pond I thought it=3D0Awas weird that no-one (+/-) us=
ed=3D
Zinc Oxide in their electric kiln=3D0Arecipes.=3D0A=3D0AI would say, at le=
ast fr=3D
om my point of view, people in the UK used=3D0AZinc Oxide to lower their fu=
si=3D
on temp, where the US used Boron. I=3D0Aoften wonder if this was a holdover=
f=3D
rom the "Bristol Glazes" which I=3D0Abelieve first replaced lead with zinc =
wh=3D
en it was recognised that lead=3D0Awas toxic in late Victorian times.=3D0A=
=3D0ASt=3D
eve I'm sure has been in the business a lot longer than I have - do=3D0Ayou=
t=3D
hink that we in the UK used Zinc Oxide a lot more than the US=3D0Apotters?=
=3D0A=3D
=3D0ARobert=3D0A=3D0AOn Sat, May 12, 2012 at 6:31 PM, Steve Mills=3D0Ainal.mud=3D
slinger@gmail.com> wrote:=3D0A> John,=3D0A> If you look at most of the reci=
pes =3D
that have their origins this side of the pond you will see a lot of that "w=
=3D
eird-ness". We didn't have Gerstley available to us for years, and some Fri=
=3D
ts can be pretty expensive, so Potters this side have learnt to do without =
=3D
them in their recipes.=3D0A> The glazes still work and work well!=3D0A> Try=
the=3D
m!=3D0A>=3D0A> Steve M=3D0A>=3D0A> Steve Mills=3D0A> Bath=3D0A> UK=3D0A> ww=
w.mudslinger.m=3D
e.uk=3D0A> Sent from my iPod=3D0A>=3D0A>=3D0A> On 12 May 2012, at 00:52, Jo=
hn Britt=3D
wrote:=3D0A> . =3DA0(There is no Gerstley bor=
ate =3D
or frits in the=3D0A>> recipe above, which strikes me a weird??)=3D0A>>=3D0=
A>> Jo=3D
hn Britt Pottery=3D0A=3D0A=3D0A=3D0A-- =3D0A-------------------------------=
----------=3D
-----------------
John Britt on sun 13 may 12
Ben,
I am not too worried about that. I am not a member of the Craze Police. I
figure if you eliminate all glaze crazing you are eliminating a lot of
great glazes!
On Sat, May 12, 2012 at 7:37 PM, Ben Morrison wrote:
> Wouldn't that craze like crazy?
>
> ------------------------------
> *From:* John Britt
> *To:* Clayart@LSV.CERAMICS.ORG
> *Sent:* Friday, May 11, 2012 4:52 PM
> *Subject:* Re: SiC electric red
>
> There is a great article in Ceramic Review July /August 2010 on silicon
> carbide electric reds by Mike Bailey. He lays it all out.
>
> Ed's Red cone 10
>
> 53 Soda Feldspar
> 17 Silica
> 15 Whiting
> 6 EPK
> 4 Talc
> 5 Zinc Oxide
>
> 0.5 Copper carbonate
> 0.3 Silicon Carbide F1200
> 1.0 Tin oxide
>
>
> He varied the firing temp, thickness, type of silicon carbide and tin. It
> is
> all there!
>
> I have not tried this but would probably just try some standard copper
> red recipes with SiC added. (There is no Gerstley borate or frits in the
> recipe above, which strikes me a weird??)
>
> John Britt Pottery
>
>
>
--
Regards,
John
AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
AWESOME BLOG: http://ncclayclub.blogspot.com
WEBPAGE: www.johnbrittpottery.com
John Britt on sun 13 may 12
Steve,
Not criticizing, just noticing that most cone 10 copper reds here have
about 10% frit or Gerstley Borate.
That may account for the fluxed reds "eating up" the silicon carbide?
On Sat, May 12, 2012 at 6:31 PM, Steve Mills
wrote:
> John,
> If you look at most of the recipes that have their origins this side of
> the pond you will see a lot of that "weird-ness". We didn't have Gerstley
> available to us for years, and some Frits can be pretty expensive, so
> Potters this side have learnt to do without them in their recipes.
> The glazes still work and work well!
> Try them!
>
> Steve M
>
> Steve Mills
> Bath
> UK
> www.mudslinger.me.uk
> Sent from my iPod
>
>
> On 12 May 2012, at 00:52, John Britt wrote:
> . (There is no Gerstley borate or frits in the
> > recipe above, which strikes me a weird??)
> >
> > John Britt Pottery
>
--
Regards,
John
AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
AWESOME BLOG: http://ncclayclub.blogspot.com
WEBPAGE: www.johnbrittpottery.com
Robert Harris on sun 13 may 12
Considering the fact that Zinc is a necessary element that people take
as supplements (espercially to combat colds) I'm not sure this is a
great argument. Also consider that people smear it all over their
faces every summer without the FDA getting too worried. Anyway, as far
as I am aware Zinc Silicate (which forms on cooling), is pretty damn
insoluble.
Usually glazes from the UK only contain 1-5% Zinc Oxide when it is
being used as a flux, rather than to form crystals.
According to Edouard Bastarache there is no known evidence of chronic
Zinc toxicity (from the digitalfire website) which is the only thing
we'd worry about. While the halflife of zinc in the body is 300 days
(long!), we excrete more than 80% of zinc compounds that are ingested
- hence the need for zinc supplements. Just off the top of my head I
can think of several classes of proteins (with many many members of
each class), that zinc is absolutely required for.
Robert
On Sun, May 13, 2012 at 9:59 PM, Ben Morrison wrote:
> Zinc is fat soluble, so if it's in an unstable glaze it could build up in
> the body of a person using zinc ware. In a stable base there is no concer=
=3D
n.
> Boron glazes wouldn't have the problem, which is probably why it's a more
> desirable material in the US to lower the temp of glazes.
>
> -Ben
>
> ________________________________
> From: Robert Harris
> To: Clayart@LSV.CERAMICS.ORG
> Sent: Saturday, May 12, 2012 9:06 PM
>
> Subject: Re: SiC electric red
>
> I would say that when I came to the US side of the pond I thought it
> was weird that no-one (+/-) used Zinc Oxide in their electric kiln
> recipes.
>
> I would say, at least from my point of view, people in the UK used
> Zinc Oxide to lower their fusion temp, where the US used Boron. I
> often wonder if this was a holdover from the "Bristol Glazes" which I
> believe first replaced lead with zinc when it was recognised that lead
> was toxic in late Victorian times.
>
> Steve I'm sure has been in the business a lot longer than I have - do
> you think that we in the UK used Zinc Oxide a lot more than the US
> potters?
>
> Robert
>
> On Sat, May 12, 2012 at 6:31 PM, Steve Mills
> wrote:
>> John,
>> If you look at most of the recipes that have their origins this side of
>> the pond you will see a lot of that "weird-ness". We didn't have Gerstle=
=3D
y
>> available to us for years, and some Frits can be pretty expensive, so
>> Potters this side have learnt to do without them in their recipes.
>> The glazes still work and work well!
>> Try them!
>>
>> Steve M
>>
>> Steve Mills
>> Bath
>> UK
>> www.mudslinger.me.uk
>> Sent from my iPod
>>
>>
>> On 12 May 2012, at 00:52, John Britt wrote:
>> . =3DA0(There is no Gerstley borate or frits in the
>>> recipe above, which strikes me a weird??)
>>>
>>> John Britt Pottery
>
>
>
> --
> ----------------------------------------------------------
>
>
--=3D20
----------------------------------------------------------
John Britt on mon 14 may 12
Now zinc is a problem? That is the first I have heard of that!
It is kind of crazy that we are making up leaching fears when we as=3D20
Americans have over 320 toxins in our bodies, including tons of hormones,=
=3D
=3D20
PBDE's, PCB's, DDT, benzene, MTBE, etc. We get them in everything from=3D20=
=3D
perfume to organic tomato sauce and the air we breath, and now the=3D20
fracking is contaminating our water.
So now we want to wipe clean out dinner plates so we don't kill any of th=
=3D
e=3D20
other toxins we are ingesting!?
Let's keep this in the scientific arena and not the fear based glaze poli=
=3D
ce.
Just my opinion,
John Britt Pottery
John Hesselberth on mon 14 may 12
On May 13, 2012, at 9:59 PM, Ben Morrison wrote:
> Zinc is fat soluble, so if it's in an unstable glaze it could build up =
=3D
in the body of a person using zinc ware. In a stable base there is no =3D
concern. Boron glazes wouldn't have the problem, which is probably why =3D
it's a more desirable material in the US to lower the temp of glazes.=3D20
>=3D20
> -Ben
Hi Ben,
I think it is probably more because of material availability on the 2 =3D
sides of the pond. Back in the first half of the 20th century, when most =
=3D
academic glaze research was done,--particularly the search for lead-free =
=3D
glazes--zinc was more reliably available to potters in Europe and boron =3D
was more available in North America. Then is became tradition.=3D20
Let's not forget that there was very little communication among potters =3D
on the two sides of the Atlantic Ocean until the internet and Clayart =3D
came along 15 or 20 years ago. I suspect that the tradition of zinc in =3D
Europe and boron in North America will gradually erode over the next 100 =
=3D
years, but traditions die hard.
Regards,
John
"If you eat a frog first thing in the morning, that will probably be the =
=3D
worst thing you do all day." Mark Twain
John Hesselberth
john@frogpondpottery.com
ivor and olive lewis on tue 15 may 12
Recalling things learned fifty years ago relating to metallurgical hazards=
,
We were warned to take precautions when arc welding Galvanised Steel.
because inhalation of fumes could cause a fever like condition, similar to
"Three Day Flu"
When I started firing with oil using the recipe books some of the recipes
contained Zinc Oxide. I always found stains where clay wadding on the door
cracked and allowed flames to escape when the damper was "in" during
reduction. The incrustation was yellow when hot and white when cold.
Regards,
Ivor Lewis,
REDHILL,
South Australia
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