pe canupp on wed 23 may 12
Hello Clayart World
I would like some help with a seafoam green glaze which is attributed to
Helen Mackersie. The ingredients are:
41 soda feldspar
27 silica
15 whiting
12 zinc oxide
5 kaolin
____
5 titanium
5 copper carb
I got the recipe from Lana Wilson's book. It is described as "shiny glaze
with some mottling and some iridescence. Must go on thick as it tends to
break."
This is a lovely glaze that I have used for years on wall tiles. When I
use this glaze on my functional plates they get scratches on the surface
that appear as though they were rubbed with sandpaper. I think it is from
the plates being stacked and (gently) slid across one another. The bottoms
of the plates were burnished when I made them so this does not account for
the problem.
Can anyone offer suggestions about why this is happening and what I can do
to correct the situation?
Thank you.
Phyllis Canupp
PCanPotter
ronroy@CA.INTER.NET on wed 23 may 12
Hi Phyllis,
If you compare the molecular formula of this glaze with the criteria
we developed in Master Cone 6 Glazes you will see it is just barely
beginning to be a durable glaze - adding more alumina and silica will
make it harder and less likely to scratch.
I can make some suggestions for a short line blend if you are
interested in doing the testing.
RR
Quoting pe canupp :
> Hello Clayart World
>
> I would like some help with a seafoam green glaze which is attributed to
> Helen Mackersie. The ingredients are:
> 41 soda feldspar
> 27 silica
> 15 whiting
> 12 zinc oxide
> 5 kaolin
> ____
> 5 titanium
> 5 copper carb
>
> I got the recipe from Lana Wilson's book. It is described as "shiny glaz=
e
> with some mottling and some iridescence. Must go on thick as it tends to
> break."
>
> This is a lovely glaze that I have used for years on wall tiles. When I
> use this glaze on my functional plates they get scratches on the surface
> that appear as though they were rubbed with sandpaper. I think it is fro=
m
> the plates being stacked and (gently) slid across one another. The botto=
ms
> of the plates were burnished when I made them so this does not account fo=
r
> the problem.
>
> Can anyone offer suggestions about why this is happening and what I can d=
o
> to correct the situation?
>
> Thank you.
> Phyllis Canupp
> PCanPotter
>
Alice DeLisle on thu 24 may 12
Ron,
I know Phyllis first asked about this glaze, but I would appreciate =3D
reading your suggestions and I believe others would too. Please share =3D
with clayart. Thanks,
Alice DeLisle
wanderland@att.net
http://www.etsy.com/shop/IslandTextures
http://www.flickr.com/photos/alice_delisle/
Ben Morrison on thu 24 may 12
That's a lot of copper for a functional plate, any ideas of the leaching wi=
=3D
th 5% copper?=3D0A=3D0A-Ben=3D0A=3D0A=3D0A=3D0A____________________________=
____=3D0A From=3D
: "ronroy@CA.INTER.NET" =3D0ATo: Clayart@LSV.CERAMICS.=
OR=3D
G =3D0ASent: Wednesday, May 23, 2012 5:55 PM=3D0ASubject: Re: Seafoam green=
gla=3D
ze help=3D0A =3D0AHi Phyllis,=3D0A=3D0AIf you compare the molecular formula=
of this=3D
glaze with the criteria=3D0Awe developed in Master Cone 6 Glazes you will =
se=3D
e it is just barely=3D0Abeginning to be a durable glaze - adding more alumi=
na=3D
and silica will=3D0Amake it harder and less likely to scratch.=3D0A=3D0AI =
can ma=3D
ke some suggestions for a short line blend if you are=3D0Ainterested in doi=
ng=3D
the testing.=3D0A=3D0ARR=3D0A=3D0A=3D0AQuoting pe canupp OM>:=3D0A=3D0A=3D
> Hello Clayart World=3D0A>=3D0A> I would like some help with a seafoam gre=
en g=3D
laze which is attributed to=3D0A> Helen Mackersie.=3DA0 The ingredients are=
:=3D0A=3D
> 41 soda feldspar=3D0A> 27 silica=3D0A> 15 whiting=3D0A> 12 zinc oxide=3D0=
A> 5 kao=3D
lin=3D0A> ____=3D0A> 5 titanium=3D0A> 5 copper carb=3D0A>=3D0A> I got the r=
ecipe from=3D
Lana Wilson's book.=3DA0 It is described as "shiny glaze=3D0A> with some m=
ottl=3D
ing and some iridescence. Must go on thick as it tends to=3D0A> break."=3D0=
A>=3D
=3D0A> This is a lovely glaze that I have used for years on wall tiles.=3DA=
0 Wh=3D
en I=3D0A> use this glaze on my functional plates they get scratches on the=
s=3D
urface=3D0A> that appear as though they were rubbed with sandpaper.=3DA0 I =
thin=3D
k it is from=3D0A> the plates being stacked and (gently) slid across one an=
ot=3D
her.=3DA0 The bottoms=3D0A> of the plates were burnished when I made them s=
o th=3D
is does not account for=3D0A> the problem.=3D0A>=3D0A> Can anyone offer sug=
gestio=3D
ns about why this is happening and what I can do=3D0A> to correct the situa=
ti=3D
on?=3D0A>=3D0A> Thank you.=3D0A> Phyllis Canupp=3D0A> PCanPotter=3D0A>
John Britt on thu 24 may 12
Ron,
According to your book it is within the silica and alumina limits.=3D20
I used insight and got 0.26 for alumina and you list the lower at 0.25.
I got 2.54 for silica and you list the lower at 2.5.
I would say it is short on boron (none) and high on zinc where you list 0=
=3D
.2=3D20
and it has 0.39.
You might drop the zinc a bit and add some boron to balance the fluxes.
But, I would guess that the glaze problem has more to do with the added=3D2=
0=3D
titanium and copper both at 5%. The titanium is probably slightly mattin=
=3D
g=3D20
it and the copper is trying to come to the now matt surface creating a=3D20=
=3D
metallic surface.=3D20
Just my opinion,
John Britt Pottery
ronroy@CA.INTER.NET on sat 26 may 12
Hi Phillis,
Here is a revision for that glaze to make it harder - expansion is
reduced as well. Call it Seafoam revised by RR #3
Mix up 500 grams along with 500 grams of the original - call the
original #1 - after you dip some tests in both mix equal amount
together and call that #2.
Fire with cones beside them - you can test them for scratching by
rubbing with fired clay, I would still not recommend either #2 or #3
as a liner glaze without having them tested for copper leaching.
By the way - it does not mater how much you burnish before firing -
the bottoms will still have to be smoothed after firing.
Results with min spar will be close as well.
Revision #3
F4 SPAR..................... 30.00
SILICA...................... 36.00
WHITING..................... 11.00
ZINC Oxide.................. 11.00
EPK......................... 12.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00
CaO 0.39*
MgO 0.00*
K2O 0.05*
Na2O 0.11*
ZnO 0.45*
Fe2O3 0.00
TiO2 0.00
Al2O3 0.34
SiO2 3.39
P2O5 0.00
Si:Al: 10.03 was 9.69
SiB:Al: 10.03
Thermal Expansion: 403.10 was 506.78
Formula Weight: 308.18
RR
Quoting pe canupp :
> Hello Clayart World
>
> I would like some help with a seafoam green glaze which is attributed to
> Helen Mackersie. The ingredients are:
> 41 soda feldspar
> 27 silica
> 15 whiting
> 12 zinc oxide
> 5 kaolin
> ____
> 5 titanium
> 5 copper carb
>
> I got the recipe from Lana Wilson's book. It is described as "shiny glaz=
e
> with some mottling and some iridescence. Must go on thick as it tends to
> break."
>
> This is a lovely glaze that I have used for years on wall tiles. When I
> use this glaze on my functional plates they get scratches on the surface
> that appear as though they were rubbed with sandpaper. I think it is fro=
m
> the plates being stacked and (gently) slid across one another. The botto=
ms
> of the plates were burnished when I made them so this does not account fo=
r
> the problem.
>
> Can anyone offer suggestions about why this is happening and what I can d=
o
> to correct the situation?
>
> Thank you.
> Phyllis Canupp
> PCanPotter
>
douglas fur on sat 26 may 12
John Britt
You wrote:
*I would say it is short on boron (none) and high on zinc where you list 0.=
2
and it has 0.39. You might drop the zinc a bit and add some boron to
balance the fluxes.
*Just for the sake of discussion- why should one add boron?
If the flux balance as-is gives the desired result what will boron bring to
the glaze?
What willl be lost?
DRB
Seola Creek
ronroy@CA.INTER.NET on sat 26 may 12
As I said - just barley durable - all the glazes in our book were
tested with 5% cooper carb and 6% rutile - so it is possible to make
stable glazes with that much copper but you need more silica and
alumina.
Adding more boron would lower both the silica and alumina and may make
the glaze even softer.
Why not test it both ways to see which works better - what whould be
you suggestion?
RR
Quoting John Britt :
> Ron,
>
> According to your book it is within the silica and alumina limits.
>
> I used insight and got 0.26 for alumina and you list the lower at 0.25.
> I got 2.54 for silica and you list the lower at 2.5.
>
> I would say it is short on boron (none) and high on zinc where you list 0=
.2
> and it has 0.39.
>
> You might drop the zinc a bit and add some boron to balance the fluxes.
>
> But, I would guess that the glaze problem has more to do with the added
> titanium and copper both at 5%. The titanium is probably slightly mattin=
g
> it and the copper is trying to come to the now matt surface creating a
> metallic surface.
>
> Just my opinion,
>
> John Britt Pottery
>
>
ronroy@CA.INTER.NET on sun 27 may 12
There are degrees of durability and they are directly related to how
much silica and alumina there are in a glaze - that is all explained
in our book John.
We have a zinc fluxed glaze in the book - it has 10% zinc oxide - so
it is possible to make a durable glaze at cone 6 with just zinc and no
boron.
Rutile is mostly TiO2 and I have no doubt that it contributes to
durability the same way rutile does>
Just melting the glaze more will not add to the durability - adding
more silica and alumina will.
Trying other glazes with high levels of silica and alumina would also
work - it would take longer - fixing a glaze seems to me a more
logical approach.
RR
Quoting John Britt :
> Ron,
>
> I am saying if the glaze exceed the zinc limits by a lot, shouldn't you
> reduce some zinc? But, then, if it does't melt well enough maybe you shou=
ld
> add some boron since there is none in there and that would help with the
> melt.
>
> My question is ,since it is within your limits for Al/Si what is the
> problem? I guess I never heard there was a lower area inside the limits
> where glazes wouldn't work?
>
> I know you tested a few glazes with copper and rutile but rutile is not
> titanium and they act differently, so perhaps the titanium is assisting i=
n
> the problem rather than the glaze base itself.
>
> Rather than "fix" a glaze that works pretty well -( It is a commonly use=
d
> glaze called Chun Clear) I would suggest she reduce the copper and
> titanium and see if she can find an area that it does't go metallic. Or
> perhaps, rather than "fix" this glaze perhaps she should choose a glaze
> that will hold them satisfactorily.
>
> John Britt Pottery
>
> On Sat, May 26, 2012 at 3:02 PM, wrote:
>
>> As I said - just barley durable - all the glazes in our book were tested
>> with 5% cooper carb and 6% rutile - so it is possible to make stable gla=
zes
>> with that much copper but you need more silica and alumina.
>>
>> Adding more boron would lower both the silica and alumina and may make t=
he
>> glaze even softer.
>>
>> Why not test it both ways to see which works better - what whould be you
>> suggestion?
>>
>> RR
>>
>>
>> Quoting John Britt :
>>
>> Ron,
>>>
>>> According to your book it is within the silica and alumina limits.
>>>
>>> I used insight and got 0.26 for alumina and you list the lower at 0.25.
>>> I got 2.54 for silica and you list the lower at 2.5.
>>>
>>> I would say it is short on boron (none) and high on zinc where you list
>>> 0.2
>>> and it has 0.39.
>>>
>>> You might drop the zinc a bit and add some boron to balance the fluxes.
>>>
>>> But, I would guess that the glaze problem has more to do with the added
>>> titanium and copper both at 5%. The titanium is probably slightly matt=
ing
>>> it and the copper is trying to come to the now matt surface creating a
>>> metallic surface.
>>>
>>> Just my opinion,
>>>
>>> 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 27 may 12
Ron,
I am saying if the glaze exceed the zinc limits by a lot, shouldn't you
reduce some zinc? But, then, if it does't melt well enough maybe you should
add some boron since there is none in there and that would help with the
melt.
My question is ,since it is within your limits for Al/Si what is the
problem? I guess I never heard there was a lower area inside the limits
where glazes wouldn't work?
I know you tested a few glazes with copper and rutile but rutile is not
titanium and they act differently, so perhaps the titanium is assisting in
the problem rather than the glaze base itself.
Rather than "fix" a glaze that works pretty well -( It is a commonly used
glaze called Chun Clear) I would suggest she reduce the copper and
titanium and see if she can find an area that it does't go metallic. Or
perhaps, rather than "fix" this glaze perhaps she should choose a glaze
that will hold them satisfactorily.
John Britt Pottery
On Sat, May 26, 2012 at 3:02 PM, wrote:
> As I said - just barley durable - all the glazes in our book were tested
> with 5% cooper carb and 6% rutile - so it is possible to make stable glaz=
es
> with that much copper but you need more silica and alumina.
>
> Adding more boron would lower both the silica and alumina and may make th=
e
> glaze even softer.
>
> Why not test it both ways to see which works better - what whould be you
> suggestion?
>
> RR
>
>
> Quoting John Britt :
>
> Ron,
>>
>> According to your book it is within the silica and alumina limits.
>>
>> I used insight and got 0.26 for alumina and you list the lower at 0.25.
>> I got 2.54 for silica and you list the lower at 2.5.
>>
>> I would say it is short on boron (none) and high on zinc where you list
>> 0.2
>> and it has 0.39.
>>
>> You might drop the zinc a bit and add some boron to balance the fluxes.
>>
>> But, I would guess that the glaze problem has more to do with the added
>> titanium and copper both at 5%. The titanium is probably slightly matti=
ng
>> it and the copper is trying to come to the now matt surface creating a
>> metallic surface.
>>
>> Just my opinion,
>>
>> 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 27 may 12
Douglas,
I was just saying that since she is having problems.......reducing the high
amount of zinc might help since it exceeds the limits Ron uses. Ron was
suggesting adding silica and alumina since it was on the low end. But I was
questioning that,since the glaze is within his limits of Al/Si why would
you need more? Why not address the large excess rather than the al/si.
I was suggesting adding boron only if you took out some zinc since it
exceeds the limits. But I know this glaze works very well (I don't think it
crazes on Helios at cone 6/7. ) and is called Chun Clear. Leah Leitson used
it a lot. So it works pretty well, but I assume that if you took out some
flux then you may need to add another to get a good melt.
John Britt Potter
On Sat, May 26, 2012 at 4:05 PM, douglas fur <23drb50@gmail.com> wrote:
>
>
> John Britt
> You wrote:
> *I would say it is short on boron (none) and high on zinc where you list
> 0.2
> and it has 0.39. You might drop the zinc a bit and add some boron to
> balance the fluxes.
>
> *
> Just for the sake of discussion- why should one add boron?
> If the flux balance as-is gives the desired result what will boron bring
> to the glaze?
> What willl be lost?
>
> DRB
> Seola Creek
>
--
Regards,
John
AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
AWESOME BLOG: http://ncclayclub.blogspot.com
WEBPAGE: www.johnbrittpottery.com
John Britt on mon 28 may 12
Ron,
Guess I didn't realize your limits were so flexible. You list only 0.2 fo=
=3D
r=3D20
ZnO. Why so low if you allow it to double?
Why not have her just try Zinc Semi-matte?
Zinc Semi-matte cone 6=3D20
36 Nepheline Syenite
13 Wollastonite
31 Silica
10 Zinc Oxide
10 EPK
Since it is so similar and you have tested it?
Or just take Chun Clear=3D20
Chun Clear cone 6
41 Soda Feldspar
15 Whiting
27 Silica
12 Zinc Oxide
5 EPK
=3D20
And sub out the whiting for wollastonite (more silica less Ca)
the drop the ZnO to 10 and add two to the EPK. That is simple and gets=3D20=
=3D
it pretty close to your Zinc Semi matte?
Chun Clear (rev.)cone 6
41 Soda Feldspar
15 Wollastonite
27 Silica
10 Zinc Oxide
7 EPK
John Britt
ronroy@CA.INTER.NET on tue 29 may 12
John - you are leaving out information - is that on purpose?
On the same page (162) in our book - the first paragraph " a number of
authors have presented so called "limits formulas". They published
them with a clear disclaimer that they are only guidelines and that
good glazes can be found outside limits."
Guide lines are simply a place to start - in this case (durability)
lab testing is the ultimate qualifier.
The reason I spend so much time making adjustments to potters glazes
is because I think it's important that all potters realize that glazes
can be adjusted - successfully!
In fact I think that supplying glazes is simply a way of perpetuating
a way of thinking that ignores some of the most important aspects of
glazes.
That is why I adjust glazes and that is why I usually don't just pass
on recipes.
It's about learning skills that can only have a beneficial effect on
the functional pots we make.
RR
Quoting John Britt :
> Ron,
>
> Guess I didn't realize your limits were so flexible. You list only 0.2 fo=
r
> ZnO. Why so low if you allow it to double?
>
> Why not have her just try Zinc Semi-matte?
>
> Zinc Semi-matte cone 6
> 36 Nepheline Syenite
> 13 Wollastonite
> 31 Silica
> 10 Zinc Oxide
> 10 EPK
>
> Since it is so similar and you have tested it?
>
> Or just take Chun Clear
>
> Chun Clear cone 6
> 41 Soda Feldspar
> 15 Whiting
> 27 Silica
> 12 Zinc Oxide
> 5 EPK
>
> And sub out the whiting for wollastonite (more silica less Ca)
> the drop the ZnO to 10 and add two to the EPK. That is simple and gets
> it pretty close to your Zinc Semi matte?
>
> Chun Clear (rev.)cone 6
> 41 Soda Feldspar
> 15 Wollastonite
> 27 Silica
> 10 Zinc Oxide
> 7 EPK
>
> John Britt
>
John Britt on wed 30 may 12
Ron,
The difference between 0.2 and 0.4 is huge. I think it is a valid question
especially for a person who is so concerned with limits it just seems that
you would have raised your limit for ZnO since you use that recipe in your
book.
I am happy that you think it's important that all potters realize that
glazes can be adjusted - successfully! I agree with you. That is way I
adjusted the Chun Clear. It is easy to adjust recipes with either the UMF
or recipe method.
You say "In fact I think that supplying glazes is simply a way of
perpetuating a way of thinking that ignores some of the most important
aspects of glazes. That is why I adjust glazes and that is why I usually
don't just pass on recipes. It's about learning skills that can only have
a beneficial effect on the functional pots we make."
The funny part is that you do "supply glazes" or pass on recipes. YOU
adjust the recipes for people and then tell them the recipes. They aren't
learning the skills- you are using your skills.
John Britt Pottery
On Tue, May 29, 2012 at 11:32 PM, wrote:
> John - you are leaving out information - is that on purpose?
>
> On the same page (162) in our book - the first paragraph " a number of
> authors have presented so called "limits formulas". They published them
> with a clear disclaimer that they are only guidelines and that good glaze=
s
> can be found outside limits."
>
> Guide lines are simply a place to start - in this case (durability) lab
> testing is the ultimate qualifier.
>
> The reason I spend so much time making adjustments to potters glazes is
> because I think it's important that all potters realize that glazes can b=
e
> adjusted - successfully!
>
> In fact I think that supplying glazes is simply a way of perpetuating a
> way of thinking that ignores some of the most important aspects of glazes=
.
>
> That is why I adjust glazes and that is why I usually don't just pass on
> recipes.
>
> It's about learning skills that can only have a beneficial effect on the
> functional pots we make.
>
> RR
>
>
>
>
>
>
> Quoting John Britt :
>
> Ron,
>>
>> Guess I didn't realize your limits were so flexible. You list only 0.2 f=
or
>> ZnO. Why so low if you allow it to double?
>>
>> Why not have her just try Zinc Semi-matte?
>>
>> Zinc Semi-matte cone 6
>> 36 Nepheline Syenite
>> 13 Wollastonite
>> 31 Silica
>> 10 Zinc Oxide
>> 10 EPK
>>
>> Since it is so similar and you have tested it?
>>
>> Or just take Chun Clear
>>
>> Chun Clear cone 6
>> 41 Soda Feldspar
>> 15 Whiting
>> 27 Silica
>> 12 Zinc Oxide
>> 5 EPK
>>
>> And sub out the whiting for wollastonite (more silica less Ca)
>> the drop the ZnO to 10 and add two to the EPK. That is simple and gets
>> it pretty close to your Zinc Semi matte?
>>
>> Chun Clear (rev.)cone 6
>> 41 Soda Feldspar
>> 15 Wollastonite
>> 27 Silica
>> 10 Zinc Oxide
>> 7 EPK
>>
>> John Britt
>>
>>
>
>
>
--
Regards,
John
AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
AWESOME BLOG: http://ncclayclub.blogspot.com
WEBPAGE: www.johnbrittpottery.com
ronroy@CA.INTER.NET on wed 30 may 12
Well I don't use limits - used to a long time ago - realized they
don't mean much - just a good place to start.
You should ask all those others who published limits - why they had
zinc so low - I don't know why but there must have been a reason. Need
a list?
Don't forget - it's the results that mater and - no-one was concerned
with durability - ours is the first book for potters that addresses
the subject.
Many potters still don't have calculation software yet - I hope that
posting the seger unity will encourage those who don't to start -
after all - it's about understanding glazes - and clay bodies - what
potter wouldn't want to know about that?
I have always thought you should post the unity formulas - think you
should have included them in your book - who wouldn't want to know
about the expansion and durability? Why not include that information?
Seems a no brainer to me.
RR
Quoting John Britt :
> Ron,
>
> Well I read your book and have seen you writing on clayart for 18 years,
> that is why I think you are concerned with limits.
>
> But you never answered the question- Why is your ZnO limit so low when yo=
u
> have glazes which double it?
>
> I figure that if someone wants the seger formula then they can punch it
> into glaze software and they will have it. It is so easy to do.
>
> But many artists don't do well with math, number and charts. All the
> retired engineers and chemists can do it with ease so I let them. The
> artists want colors and glaze recipes.
>
> So, since you post recipes and I post recipes I guess that if I posted th=
e
> UMF, we would be the same then?
>
>
>
> On Wed, May 30, 2012 at 4:27 PM, wrote:
>
>> John - just out of curiosity - what makes you think I am so concerned
>> about limits?
>>
>> You are right - I pass on recipes - but always with the Seger molecular
>> formula - in case anyone wants to see what I have done to adjust a glaze=
-
>> It's part of the finding out why - that is so important. That is differe=
nt
>> from just posting recipes.
>>
>> What is usually lacking is the feed back from the testing so we all coul=
d
>> become better at this.
>>
>>
>> RR
>>
>>
>>
>> Quoting John Britt :
>>
>> Ron,
>>>
>>> The difference between 0.2 and 0.4 is huge. I think it is a valid quest=
ion
>>> especially for a person who is so concerned with limits it just seems t=
hat
>>> you would have raised your limit for ZnO since you use that recipe in y=
our
>>> book.
>>>
>>> I am happy that you think it's important that all potters realize that
>>> glazes can be adjusted - successfully! I agree with you. That is way I
>>> adjusted the Chun Clear. It is easy to adjust recipes with either the U=
MF
>>> or recipe method.
>>>
>>> You say "In fact I think that supplying glazes is simply a way of
>>> perpetuating a way of thinking that ignores some of the most important
>>> aspects of glazes. That is why I adjust glazes and that is why I usuall=
y
>>> don't just pass on recipes. It's about learning skills that can only h=
ave
>>> a beneficial effect on the functional pots we make."
>>>
>>> The funny part is that you do "supply glazes" or pass on recipes. YOU
>>> adjust the recipes for people and then tell them the recipes. They aren=
't
>>> learning the skills- you are using your skills.
>>>
>>> John Britt Pottery
>>>
>>>
>>>
>>>
>>>
>>> On Tue, May 29, 2012 at 11:32 PM, wrote:
>>>
>>> John - you are leaving out information - is that on purpose?
>>>>
>>>> On the same page (162) in our book - the first paragraph " a number of
>>>> authors have presented so called "limits formulas". They published the=
m
>>>> with a clear disclaimer that they are only guidelines and that good
>>>> glazes
>>>> can be found outside limits."
>>>>
>>>> Guide lines are simply a place to start - in this case (durability) la=
b
>>>> testing is the ultimate qualifier.
>>>>
>>>> The reason I spend so much time making adjustments to potters glazes i=
s
>>>> because I think it's important that all potters realize that glazes ca=
n
>>>> be
>>>> adjusted - successfully!
>>>>
>>>> In fact I think that supplying glazes is simply a way of perpetuating =
a
>>>> way of thinking that ignores some of the most important aspects of
>>>> glazes.
>>>>
>>>> That is why I adjust glazes and that is why I usually don't just pass =
on
>>>> recipes.
>>>>
>>>> It's about learning skills that can only have a beneficial effect on t=
he
>>>> functional pots we make.
>>>>
>>>> RR
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Quoting John Britt :
>>>>
>>>> Ron,
>>>>
>>>>>
>>>>> Guess I didn't realize your limits were so flexible. You list only 0.=
2
>>>>> for
>>>>> ZnO. Why so low if you allow it to double?
>>>>>
>>>>> Why not have her just try Zinc Semi-matte?
>>>>>
>>>>> Zinc Semi-matte cone 6
>>>>> 36 Nepheline Syenite
>>>>> 13 Wollastonite
>>>>> 31 Silica
>>>>> 10 Zinc Oxide
>>>>> 10 EPK
>>>>>
>>>>> Since it is so similar and you have tested it?
>>>>>
>>>>> Or just take Chun Clear
>>>>>
>>>>> Chun Clear cone 6
>>>>> 41 Soda Feldspar
>>>>> 15 Whiting
>>>>> 27 Silica
>>>>> 12 Zinc Oxide
>>>>> 5 EPK
>>>>>
>>>>> And sub out the whiting for wollastonite (more silica less Ca)
>>>>> the drop the ZnO to 10 and add two to the EPK. That is simple and get=
s
>>>>> it pretty close to your Zinc Semi matte?
>>>>>
>>>>> Chun Clear (rev.)cone 6
>>>>> 41 Soda Feldspar
>>>>> 15 Wollastonite
>>>>> 27 Silica
>>>>> 10 Zinc Oxide
>>>>> 7 EPK
>>>>>
>>>>> John Britt
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>> --
>>> Regards,
>>>
>>> John
>>>
>>> AWESOME VIDEOS:
>>> http://www.youtube.com/user/**johnbrittpotteryser/johnbrittpottery>
>>>
>>> AWESOME BLOG: http://ncclayclub.blogspot.com
>>>
>>> WEBPAGE: www.johnbrittpottery.com
>>>
>>>
>>
>>
>>
>
>
> --
> Regards,
>
> John
>
> AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
>
> AWESOME BLOG: http://ncclayclub.blogspot.com
>
> WEBPAGE: www.johnbrittpottery.com
>
John Britt on wed 30 may 12
Ron,
Oh, and then the obvious that you have your own set of limits in your book
and on Insight.
On Wed, May 30, 2012 at 9:17 AM, John Britt wro=
te:
> Ron,
>
> The difference between 0.2 and 0.4 is huge. I think it is a valid questio=
n
> especially for a person who is so concerned with limits it just seems tha=
t
> you would have raised your limit for ZnO since you use that recipe in you=
r
> book.
>
> I am happy that you think it's important that all potters realize that
> glazes can be adjusted - successfully! I agree with you. That is way I
> adjusted the Chun Clear. It is easy to adjust recipes with either the UMF
> or recipe method.
>
> You say "In fact I think that supplying glazes is simply a way of
> perpetuating a way of thinking that ignores some of the most important
> aspects of glazes. That is why I adjust glazes and that is why I usually
> don't just pass on recipes. It's about learning skills that can only hav=
e
> a beneficial effect on the functional pots we make."
>
> The funny part is that you do "supply glazes" or pass on recipes. YOU
> adjust the recipes for people and then tell them the recipes. They aren't
> learning the skills- you are using your skills.
>
> John Britt Pottery
>
>
>
>
>
> On Tue, May 29, 2012 at 11:32 PM, wrote:
>
>> John - you are leaving out information - is that on purpose?
>>
>> On the same page (162) in our book - the first paragraph " a number of
>> authors have presented so called "limits formulas". They published them
>> with a clear disclaimer that they are only guidelines and that good glaz=
es
>> can be found outside limits."
>>
>> Guide lines are simply a place to start - in this case (durability) lab
>> testing is the ultimate qualifier.
>>
>> The reason I spend so much time making adjustments to potters glazes is
>> because I think it's important that all potters realize that glazes can =
be
>> adjusted - successfully!
>>
>> In fact I think that supplying glazes is simply a way of perpetuating a
>> way of thinking that ignores some of the most important aspects of glaze=
s.
>>
>> That is why I adjust glazes and that is why I usually don't just pass on
>> recipes.
>>
>> It's about learning skills that can only have a beneficial effect on the
>> functional pots we make.
>>
>> RR
>>
>>
>>
>>
>>
>>
>> Quoting John Britt :
>>
>> Ron,
>>>
>>> Guess I didn't realize your limits were so flexible. You list only 0.2
>>> for
>>> ZnO. Why so low if you allow it to double?
>>>
>>> Why not have her just try Zinc Semi-matte?
>>>
>>> Zinc Semi-matte cone 6
>>> 36 Nepheline Syenite
>>> 13 Wollastonite
>>> 31 Silica
>>> 10 Zinc Oxide
>>> 10 EPK
>>>
>>> Since it is so similar and you have tested it?
>>>
>>> Or just take Chun Clear
>>>
>>> Chun Clear cone 6
>>> 41 Soda Feldspar
>>> 15 Whiting
>>> 27 Silica
>>> 12 Zinc Oxide
>>> 5 EPK
>>>
>>> And sub out the whiting for wollastonite (more silica less Ca)
>>> the drop the ZnO to 10 and add two to the EPK. That is simple and gets
>>> it pretty close to your Zinc Semi matte?
>>>
>>> Chun Clear (rev.)cone 6
>>> 41 Soda Feldspar
>>> 15 Wollastonite
>>> 27 Silica
>>> 10 Zinc Oxide
>>> 7 EPK
>>>
>>> John Britt
>>>
>>>
>>
>>
>>
>
>
> --
> Regards,
>
> John
>
> AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
>
> AWESOME BLOG: http://ncclayclub.blogspot.com
>
> WEBPAGE: www.johnbrittpottery.com
>
>
--
Regards,
John
AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
AWESOME BLOG: http://ncclayclub.blogspot.com
WEBPAGE: www.johnbrittpottery.com
John Britt on wed 30 may 12
Ron,
Well I read your book and have seen you writing on clayart for 18 years,
that is why I think you are concerned with limits.
But you never answered the question- Why is your ZnO limit so low when you
have glazes which double it?
I figure that if someone wants the seger formula then they can punch it
into glaze software and they will have it. It is so easy to do.
But many artists don't do well with math, number and charts. All the
retired engineers and chemists can do it with ease so I let them. The
artists want colors and glaze recipes.
So, since you post recipes and I post recipes I guess that if I posted the
UMF, we would be the same then?
On Wed, May 30, 2012 at 4:27 PM, wrote:
> John - just out of curiosity - what makes you think I am so concerned
> about limits?
>
> You are right - I pass on recipes - but always with the Seger molecular
> formula - in case anyone wants to see what I have done to adjust a glaze =
-
> It's part of the finding out why - that is so important. That is differen=
t
> from just posting recipes.
>
> What is usually lacking is the feed back from the testing so we all could
> become better at this.
>
>
> RR
>
>
>
> Quoting John Britt :
>
> Ron,
>>
>> The difference between 0.2 and 0.4 is huge. I think it is a valid questi=
on
>> especially for a person who is so concerned with limits it just seems th=
at
>> you would have raised your limit for ZnO since you use that recipe in yo=
ur
>> book.
>>
>> I am happy that you think it's important that all potters realize that
>> glazes can be adjusted - successfully! I agree with you. That is way I
>> adjusted the Chun Clear. It is easy to adjust recipes with either the UM=
F
>> or recipe method.
>>
>> You say "In fact I think that supplying glazes is simply a way of
>> perpetuating a way of thinking that ignores some of the most important
>> aspects of glazes. That is why I adjust glazes and that is why I usually
>> don't just pass on recipes. It's about learning skills that can only ha=
ve
>> a beneficial effect on the functional pots we make."
>>
>> The funny part is that you do "supply glazes" or pass on recipes. YOU
>> adjust the recipes for people and then tell them the recipes. They aren'=
t
>> learning the skills- you are using your skills.
>>
>> John Britt Pottery
>>
>>
>>
>>
>>
>> On Tue, May 29, 2012 at 11:32 PM, wrote:
>>
>> John - you are leaving out information - is that on purpose?
>>>
>>> On the same page (162) in our book - the first paragraph " a number of
>>> authors have presented so called "limits formulas". They published them
>>> with a clear disclaimer that they are only guidelines and that good
>>> glazes
>>> can be found outside limits."
>>>
>>> Guide lines are simply a place to start - in this case (durability) lab
>>> testing is the ultimate qualifier.
>>>
>>> The reason I spend so much time making adjustments to potters glazes is
>>> because I think it's important that all potters realize that glazes can
>>> be
>>> adjusted - successfully!
>>>
>>> In fact I think that supplying glazes is simply a way of perpetuating a
>>> way of thinking that ignores some of the most important aspects of
>>> glazes.
>>>
>>> That is why I adjust glazes and that is why I usually don't just pass o=
n
>>> recipes.
>>>
>>> It's about learning skills that can only have a beneficial effect on th=
e
>>> functional pots we make.
>>>
>>> RR
>>>
>>>
>>>
>>>
>>>
>>>
>>> Quoting John Britt :
>>>
>>> Ron,
>>>
>>>>
>>>> Guess I didn't realize your limits were so flexible. You list only 0.2
>>>> for
>>>> ZnO. Why so low if you allow it to double?
>>>>
>>>> Why not have her just try Zinc Semi-matte?
>>>>
>>>> Zinc Semi-matte cone 6
>>>> 36 Nepheline Syenite
>>>> 13 Wollastonite
>>>> 31 Silica
>>>> 10 Zinc Oxide
>>>> 10 EPK
>>>>
>>>> Since it is so similar and you have tested it?
>>>>
>>>> Or just take Chun Clear
>>>>
>>>> Chun Clear cone 6
>>>> 41 Soda Feldspar
>>>> 15 Whiting
>>>> 27 Silica
>>>> 12 Zinc Oxide
>>>> 5 EPK
>>>>
>>>> And sub out the whiting for wollastonite (more silica less Ca)
>>>> the drop the ZnO to 10 and add two to the EPK. That is simple and gets
>>>> it pretty close to your Zinc Semi matte?
>>>>
>>>> Chun Clear (rev.)cone 6
>>>> 41 Soda Feldspar
>>>> 15 Wollastonite
>>>> 27 Silica
>>>> 10 Zinc Oxide
>>>> 7 EPK
>>>>
>>>> John Britt
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>> --
>> Regards,
>>
>> John
>>
>> AWESOME VIDEOS: http://www.youtube.com/user/**johnbrittpotteryww.youtube.com/user/johnbrittpottery>
>>
>> AWESOME BLOG: http://ncclayclub.blogspot.com
>>
>> WEBPAGE: www.johnbrittpottery.com
>>
>>
>
>
>
--
Regards,
John
AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
AWESOME BLOG: http://ncclayclub.blogspot.com
WEBPAGE: www.johnbrittpottery.com
ronroy@CA.INTER.NET on wed 30 may 12
John - just out of curiosity - what makes you think I am so concerned
about limits?
You are right - I pass on recipes - but always with the Seger
molecular formula - in case anyone wants to see what I have done to
adjust a glaze - It's part of the finding out why - that is so
important. That is different from just posting recipes.
What is usually lacking is the feed back from the testing so we all
could become better at this.
RR
Quoting John Britt :
> Ron,
>
> The difference between 0.2 and 0.4 is huge. I think it is a valid questio=
n
> especially for a person who is so concerned with limits it just seems tha=
t
> you would have raised your limit for ZnO since you use that recipe in you=
r
> book.
>
> I am happy that you think it's important that all potters realize that
> glazes can be adjusted - successfully! I agree with you. That is way I
> adjusted the Chun Clear. It is easy to adjust recipes with either the UMF
> or recipe method.
>
> You say "In fact I think that supplying glazes is simply a way of
> perpetuating a way of thinking that ignores some of the most important
> aspects of glazes. That is why I adjust glazes and that is why I usually
> don't just pass on recipes. It's about learning skills that can only hav=
e
> a beneficial effect on the functional pots we make."
>
> The funny part is that you do "supply glazes" or pass on recipes. YOU
> adjust the recipes for people and then tell them the recipes. They aren't
> learning the skills- you are using your skills.
>
> John Britt Pottery
>
>
>
>
>
> On Tue, May 29, 2012 at 11:32 PM, wrote:
>
>> John - you are leaving out information - is that on purpose?
>>
>> On the same page (162) in our book - the first paragraph " a number of
>> authors have presented so called "limits formulas". They published them
>> with a clear disclaimer that they are only guidelines and that good glaz=
es
>> can be found outside limits."
>>
>> Guide lines are simply a place to start - in this case (durability) lab
>> testing is the ultimate qualifier.
>>
>> The reason I spend so much time making adjustments to potters glazes is
>> because I think it's important that all potters realize that glazes can =
be
>> adjusted - successfully!
>>
>> In fact I think that supplying glazes is simply a way of perpetuating a
>> way of thinking that ignores some of the most important aspects of glaze=
s.
>>
>> That is why I adjust glazes and that is why I usually don't just pass on
>> recipes.
>>
>> It's about learning skills that can only have a beneficial effect on the
>> functional pots we make.
>>
>> RR
>>
>>
>>
>>
>>
>>
>> Quoting John Britt :
>>
>> Ron,
>>>
>>> Guess I didn't realize your limits were so flexible. You list only 0.2 =
for
>>> ZnO. Why so low if you allow it to double?
>>>
>>> Why not have her just try Zinc Semi-matte?
>>>
>>> Zinc Semi-matte cone 6
>>> 36 Nepheline Syenite
>>> 13 Wollastonite
>>> 31 Silica
>>> 10 Zinc Oxide
>>> 10 EPK
>>>
>>> Since it is so similar and you have tested it?
>>>
>>> Or just take Chun Clear
>>>
>>> Chun Clear cone 6
>>> 41 Soda Feldspar
>>> 15 Whiting
>>> 27 Silica
>>> 12 Zinc Oxide
>>> 5 EPK
>>>
>>> And sub out the whiting for wollastonite (more silica less Ca)
>>> the drop the ZnO to 10 and add two to the EPK. That is simple and gets
>>> it pretty close to your Zinc Semi matte?
>>>
>>> Chun Clear (rev.)cone 6
>>> 41 Soda Feldspar
>>> 15 Wollastonite
>>> 27 Silica
>>> 10 Zinc Oxide
>>> 7 EPK
>>>
>>> John Britt
>>>
>>>
>>
>>
>>
>
>
> --
> Regards,
>
> John
>
> AWESOME VIDEOS: http://www.youtube.com/user/johnbrittpottery
>
> AWESOME BLOG: http://ncclayclub.blogspot.com
>
> WEBPAGE: www.johnbrittpottery.com
>
Terry on thu 31 may 12
Try as you may, you will never be the same.
Not with the avenue you continue to pursue.
John Britt on sat 2 jun 12
Terry,
We were doing so well without your snide comment.=3D20
John Britt Pottery
| |
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