Nancy Gallagher on tue 22 may 12
Thanks to everyone who has emailed me off and on list (I get mixed up
which email came from which source) about my butter yellow terrasig w/no
ball mill / rock tumbler dilemma.
I've gotten a few things to try, although I was kind of hoping for more
of a YES, YOU CAN DO IT, kind of thing... but I'm happy to have at least
a couple of resources to work with. This will be done on earthenware and
combined with a stain and I'm hoping experiments will eventually yield
to what I envision in my mind and further develop into a full fledged
earthenware conversion. I love that clay.
Nancy
potterybyjohn on fri 25 may 12
I noticed that the CAD video today mentioned adding stain to terra sig. Br=
iefly, they said they get the specific gravity lower to accept the added st=
ain. I think I need to try this myself. John.
Vince Pitelka on fri 25 may 12
Potterybyjohn wrote:
"I noticed that the CAD video today mentioned adding stain to terra sig.
Briefly, they said they get the specific gravity lower to accept the added
stain. I think I need to try this myself."
John -
This seems completely counterintuitive, but that doesn't mean that it won't
work. The stain particles are like giant boulders compared to the refined
clay platelets in the terra sig. It seems like lowering the specific
gravity would cause them to settle out super fast. If you do try this,
please report back to us about the results.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net
http://iweb.tntech.edu/wpitelka/
Ben Morrison on sat 26 may 12
I was thinking the same thing as Vince. The encapsulated stains are fine po=
=3D
wders but they are larger than the clay, and extremely heavy by comparison.=
=3D
=3D0A=3D0A-Ben=3D0A=3D0A=3D0A=3D0A________________________________=3D0A Fro=
m: Vince Pitel=3D
ka =3D0ATo: Clayart@LSV.CERAMICS.ORG =3D0ASent: Friday=
, Ma=3D
y 25, 2012 9:37 PM=3D0ASubject: Re: Yellow Terra Sig.=3D0A =3D0APotterybyjo=
hn wro=3D
te:=3D0A"I noticed that the CAD video today mentioned adding stain to terra=
s=3D
ig.=3D0ABriefly, they said they get the specific gravity lower to accept th=
e =3D
added=3D0Astain. I think I need to try this myself."=3D0A=3D0AJohn -=3D0ATh=
is seems=3D
completely counterintuitive, but that doesn't mean that it won't=3D0Awork.=
=3D
=3DA0 The stain particles are like giant boulders compared to the refined=
=3D0Ac=3D
lay platelets in the terra sig.=3DA0 It seems like lowering the specific=3D=
0Agr=3D
avity would cause them to settle out super fast.=3DA0 If you do try this,=
=3D0Ap=3D
lease report back to us about the results.=3D0A- Vince=3D0A=3D0AVince Pitel=
ka=3D0AA=3D
ppalachian Center for Craft=3D0ATennessee Tech University=3D0Avpitelka@dtcc=
om.n=3D
et=3D0Ahttp://iweb.tntech.edu/wpitelka/
Vince Pitelka on sun 27 may 12
Ben Morrison wrote:
"Well the particles of stain should be harder than the balls in the ball
mill. However ball milling an encapsulated stains such as the yellow
yttrium, or praesidium stains could break apart the encapsulation making th=
e
toxic materials readily available to contaminate the potters body or the
bodies of the customer much more easily."
Hi Ben -
High-fired porcelain ball-mill media are harder than glass and will break
down stain particles just fine. Someone else posted a message that if you
happen to be using zirconium inclusion stains, this breakdown could expose
the toxic materials in the stain, and that would indeed be a big problem. =
I
would not ball mill any zirconium inclusion stain, but with standard Mason
stains and other silica-glass-based stains it should work fine.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net
http://iweb.tntech.edu/wpitelka/
Vince Pitelka on sun 27 may 12
Sumi von Dassow wrote:
"I think the point of lowering the specific gravity of the sig was so it
wouldn't be too thick and potentially peel off the pot. I presume Jeremy
Randall stirs his sig well before applying to mix it the settled stain."
Hi Sumi -
I think you misunderstood. The directions as reported to us in the origina=
l
post said to thin the sig even more than you normally would for application
if you are going to add a stain, and my response was that if the sig was
thinned that much, the very coarse stain particles (in comparison to the
refined clay platelets in the sig) would settle out so quickly as to impede
use of the mixture. But I also encouraged them to go ahead and try it and
report back to us.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net
http://iweb.tntech.edu/wpitelka/
Steve Mills on sun 27 may 12
Dipping my toe in as a non terra-sig person, my usual answer to relatively =
c=3D
oarse materials is to resort to the ball mill. Some of my glazes are milled=
t=3D
o finer than 250 mesh to aid adhesion.=3D20
Perhaps milling the colour finer would restore the balance.=3D20
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod
On 26 May 2012, at 05:37, Vince Pitelka wrote:
> Potterybyjohn wrote:
> "I noticed that the CAD video today mentioned adding stain to terra sig.
> Briefly, they said they get the specific gravity lower to accept the adde=
d=3D
> stain. I think I need to try this myself."
>=3D20
> John -
> This seems completely counterintuitive, but that doesn't mean that it won=
'=3D
t
> work. The stain particles are like giant boulders compared to the refine=
d=3D
> clay platelets in the terra sig. It seems like lowering the specific
> gravity would cause them to settle out super fast. If you do try this,
> please report back to us about the results.
> - Vince
>=3D20
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net
> http://iweb.tntech.edu/wpitelka/
Sumi von Dassow on sun 27 may 12
I think the point of lowering the specific gravity of the sig was so it
wouldn't be too thick and potentially peel off the pot. I presume Jeremy
Randall stirs his sig well before applying to mix it the settled stain.
Sumi
> I was thinking the same thing as Vince. The encapsulated stains are fine =
powders but they are larger than the clay, and extremely heavy by compariso=
n.
>
> -Ben
>
>
>
> ________________________________
> From: Vince Pitelka
> To: Clayart@LSV.CERAMICS.ORG
> Sent: Friday, May 25, 2012 9:37 PM
> Subject: Re: Yellow Terra Sig.
>
> Potterybyjohn wrote:
> "I noticed that the CAD video today mentioned adding stain to terra sig.
> Briefly, they said they get the specific gravity lower to accept the adde=
d
> stain. I think I need to try this myself."
>
> John -
> This seems completely counterintuitive, but that doesn't mean that it won=
't
> work. The stain particles are like giant boulders compared to the refine=
d
> clay platelets in the terra sig. It seems like lowering the specific
> gravity would cause them to settle out super fast. If you do try this,
> please report back to us about the results.
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net
> http://iweb.tntech.edu/wpitelka/
>
>
Ben Morrison on sun 27 may 12
Well the particles of stain should be harder than the balls in the ball mil=
=3D
l. However ball milling an encapsulated stains such as the yellow yttrium, =
=3D
or praesidium stains could break apart the encapsulation making the toxic m=
=3D
aterials readily available to contaminate the potters body or the bodies of=
=3D
the customer much more easily.=3D0A=3D0A-Ben=3D0A=3D0A=3D0A=3D0A__________=
____________=3D
__________=3D0A From: Steve Mills =3D0ATo: C=
laya=3D
rt@LSV.CERAMICS.ORG =3D0ASent: Sunday, May 27, 2012 10:01 AM=3D0ASubject: R=
e: Y=3D
ellow Terra Sig.=3D0A =3D0ADipping my toe in as a non terra-sig person, my =
usua=3D
l answer to relatively coarse materials is to resort to the ball mill. Some=
=3D
of my glazes are milled to finer than 250 mesh to aid adhesion. =3D0APerha=
ps=3D
milling the colour finer would restore the balance. =3D0A=3D0ASteve M=3D0A=
=3D0A=3D0A=3D
Steve Mills=3D0ABath=3D0AUK=3D0Awww.mudslinger.me.uk=3D0ASent from my iPod=
=3D0A=3D0A=3D0A=3D
On 26 May 2012, at 05:37, Vince Pitelka wrote:=3D0A=
=3D0A>=3D
Potterybyjohn wrote:=3D0A> "I noticed that the CAD video today mentioned a=
dd=3D
ing stain to terra sig.=3D0A> Briefly, they said they get the specific grav=
it=3D
y lower to accept the added=3D0A> stain. I think I need to try this myself.=
"=3D
=3D0A> =3D0A> John -=3D0A> This seems completely counterintuitive, but that=
doesn=3D
't mean that it won't=3D0A> work.=3DA0 The stain particles are like giant b=
ould=3D
ers compared to the refined=3D0A> clay platelets in the terra sig.=3DA0 It =
seem=3D
s like lowering the specific=3D0A> gravity would cause them to settle out s=
up=3D
er fast.=3DA0 If you do try this,=3D0A> please report back to us about the =
resu=3D
lts.=3D0A> - Vince=3D0A> =3D0A> Vince Pitelka=3D0A> Appalachian Center for =
Craft=3D0A=3D
> Tennessee Tech University=3D0A> vpitelka@dtccom.net=3D0A> http://iweb.tnt=
ech.=3D
edu/wpitelka/
Steve Mills on mon 28 may 12
Interesting!
My experience of stain and colour preparation is that the ingredients for t=
h=3D
e colour are melted together and then rapidly cooled either on a very cold =
s=3D
urface or in a water bath before being water-ground. The latter in a Ball M=
i=3D
ll.=3D20
Micro-encapsulation does involve coating grains with an inert material whic=
h=3D
further Ball-milling could destroy, However the potential hazard would b=
e=3D
mainly at the point of milling, decreasing substantially with dilution as =
t=3D
he milled material is added to a slip or similar.=3D20
Examination of MSDS of coloured slips and the like will demonstrate that AL=
L=3D
ingredients including water are included in the hazard calculation.=3D20
Dry Clay dust is substantially more hazardous than slips containing small p=
e=3D
rcentages of stain.=3D20
Anyone who eats, drinks or smokes (all of which involve hand to mouth conta=
c=3D
t) in a clay workshop has only themselves to blame for subsequent problems.=
=3D20=3D
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod
On 27 May 2012, at 21:30, Ben Morrison wrote:
> Well the particles of stain should be harder than the balls in the ball m=
i=3D
ll. However ball milling an encapsulated stains such as the yellow yttrium,=
o=3D
r praesidium stains could break apart the encapsulation making the toxic ma=
t=3D
erials readily available to contaminate the potters body or the bodies of t=
h=3D
e customer much more easily.
>=3D20
> -Ben
>=3D20
> From: Steve Mills
> To: Clayart@LSV.CERAMICS.ORG=3D20
> Sent: Sunday, May 27, 2012 10:01 AM
> Subject: Re: Yellow Terra Sig.
>=3D20
> Dipping my toe in as a non terra-sig person, my usual answer to relativel=
y=3D
coarse materials is to resort to the ball mill. Some of my glazes are mill=
e=3D
d to finer than 250 mesh to aid adhesion.=3D20
> Perhaps milling the colour finer would restore the balance.=3D20
>=3D20
> Steve M
>=3D20
>=3D20
> Steve Mills
> Bath
> UK
> www.mudslinger.me.uk
> Sent from my iPod
>=3D20
>=3D20
> On 26 May 2012, at 05:37, Vince Pitelka wrote:
>=3D20
> > Potterybyjohn wrote:
> > "I noticed that the CAD video today mentioned adding stain to terra sig=
.=3D
> > Briefly, they said they get the specific gravity lower to accept the ad=
d=3D
ed
> > stain. I think I need to try this myself."
> >=3D20
> > John -
> > This seems completely counterintuitive, but that doesn't mean that it w=
o=3D
n't
> > work. The stain particles are like giant boulders compared to the refi=
n=3D
ed
> > clay platelets in the terra sig. It seems like lowering the specific
> > gravity would cause them to settle out super fast. If you do try this,
> > please report back to us about the results.
> > - Vince
> >=3D20
> > Vince Pitelka
> > Appalachian Center for Craft
> > Tennessee Tech University
> > vpitelka@dtccom.net
> > http://iweb.tntech.edu/wpitelka/
>=3D20
>=3D20
Steve Mills on mon 28 may 12
Agreed, that is possible, but the dilution factor which is very much part o=
f=3D
the hazard identifying process will ensure that a seriously large amount o=
f=3D
"use" will have to have taken place before any contamination is traceable.=
=3D20=3D
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod
On 28 May 2012, at 18:09, Robert Harris wrote:
> I think that the micro-encapsulation, especially for things like
> Cadmium, are to prevent leaching after firing, rather than for safety
> of the potter.
> Obviously if you destroy the micro-encapsulation you are more likely
> to get leaching.
>=3D20
> Robert
>=3D20
>=3D20
> On Sun, May 27, 2012 at 7:21 PM, Steve Mills
> wrote:
>> Interesting!
>> My experience of stain and colour preparation is that the ingredients fo=
r=3D
the colour are melted together and then rapidly cooled either on a very co=
l=3D
d surface or in a water bath before being water-ground. The latter in a Bal=
l=3D
Mill.
>> Micro-encapsulation does involve coating grains with an inert material w=
h=3D
ich further Ball-milling could destroy, However the potential hazard woul=
d=3D
be mainly at the point of milling, decreasing substantially with dilution =
a=3D
s the milled material is added to a slip or similar.
>> Examination of MSDS of coloured slips and the like will demonstrate that=
A=3D
LL ingredients including water are included in the hazard calculation.
>> Dry Clay dust is substantially more hazardous than slips containing smal=
l=3D
percentages of stain.
>> Anyone who eats, drinks or smokes (all of which involve hand to mouth co=
n=3D
tact) in a clay workshop has only themselves to blame for subsequent proble=
m=3D
s.
>>=3D20
>> Steve M
>>=3D20
>>=3D20
>> Steve Mills
>> Bath
>> UK
>> www.mudslinger.me.uk
>> Sent from my iPod
>>=3D20
>>=3D20
>> On 27 May 2012, at 21:30, Ben Morrison wrote:
>>=3D20
>>> Well the particles of stain should be harder than the balls in the ball=
m=3D
ill. However ball milling an encapsulated stains such as the yellow yttrium=
,=3D
or praesidium stains could break apart the encapsulation making the toxic =
m=3D
aterials readily available to contaminate the potters body or the bodies of=
t=3D
he customer much more easily.
>>>=3D20
>>> -Ben
>>>=3D20
>>> From: Steve Mills
>>> To: Clayart@LSV.CERAMICS.ORG
>>> Sent: Sunday, May 27, 2012 10:01 AM
>>> Subject: Re: Yellow Terra Sig.
>>>=3D20
>>> Dipping my toe in as a non terra-sig person, my usual answer to relativ=
e=3D
ly coarse materials is to resort to the ball mill. Some of my glazes are mi=
l=3D
led to finer than 250 mesh to aid adhesion.
>>> Perhaps milling the colour finer would restore the balance.
>>>=3D20
>>> Steve M
>>>=3D20
>>>=3D20
>>> Steve Mills
>>> Bath
>>> UK
>>> www.mudslinger.me.uk
>>> Sent from my iPod
>>>=3D20
>>>=3D20
>>> On 26 May 2012, at 05:37, Vince Pitelka wrote:
>>>=3D20
>>>> Potterybyjohn wrote:
>>>> "I noticed that the CAD video today mentioned adding stain to terra si=
g=3D
.
>>>> Briefly, they said they get the specific gravity lower to accept the a=
d=3D
ded
>>>> stain. I think I need to try this myself."
>>>>=3D20
>>>> John -
>>>> This seems completely counterintuitive, but that doesn't mean that it =
w=3D
on't
>>>> work. The stain particles are like giant boulders compared to the ref=
i=3D
ned
>>>> clay platelets in the terra sig. It seems like lowering the specific
>>>> gravity would cause them to settle out super fast. If you do try this=
,=3D
>>>> please report back to us about the results.
>>>> - Vince
>>>>=3D20
>>>> Vince Pitelka
>>>> Appalachian Center for Craft
>>>> Tennessee Tech University
>>>> vpitelka@dtccom.net
>>>> http://iweb.tntech.edu/wpitelka/
>>>=3D20
>>>=3D20
>=3D20
>=3D20
>=3D20
> --=3D20
> ----------------------------------------------------------
Sumi von Dassow on mon 28 may 12
Vince
No, I didn't misunderstand anything. The point Jeremy Randall made
regarding specific gravity was that if the specific gravity is above the
target range the terra sig is more likely to peel, which is indeed a
pernicious problem with terra sig. He advises lowering the specific
gravity by adding water if you are planning to add stain so that when
you add stain the specific gravity doesn't end up above the target
range. Yes, if the terra sig is thinner then the heavy stain particles
are likely to settle more, but I was simply pointing out that if you
stir before applying - and continue to stir while applying - you will be
able to reincorporate the stain into the terra sig. Clearly what he does
works well for Mr. Randall.
I use terra sig frequently, occasionally adding mason stains, and I
never bother to check specific gravity - but I do know if the sig is too
thick it is more likely to peel in the firing, so I keep mine thin. I
also know that adding too much stain makes the sig burnish less well,
but that is a matter of degree and taste. Experience is the best guide
when using terra sig as in all things, but if you are inexperienced with
terra sig knowing how to measure and adjust specific gravity may be a
helpful tool.
Sumi
> Sumi von Dassow wrote:
> "I think the point of lowering the specific gravity of the sig was so it
> wouldn't be too thick and potentially peel off the pot. I presume Jeremy
> Randall stirs his sig well before applying to mix it the settled stain."
>
> Hi Sumi -
> I think you misunderstood. The directions as reported to us in the origi=
nal
> post said to thin the sig even more than you normally would for applicati=
on
> if you are going to add a stain, and my response was that if the sig was
> thinned that much, the very coarse stain particles (in comparison to the
> refined clay platelets in the sig) would settle out so quickly as to impe=
de
> use of the mixture. But I also encouraged them to go ahead and try it an=
d
> report back to us.
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net
> http://iweb.tntech.edu/wpitelka/
>
>
>
>
>
>
Robert Harris on mon 28 may 12
I think that the micro-encapsulation, especially for things like
Cadmium, are to prevent leaching after firing, rather than for safety
of the potter.
Obviously if you destroy the micro-encapsulation you are more likely
to get leaching.
Robert
On Sun, May 27, 2012 at 7:21 PM, Steve Mills
wrote:
> Interesting!
> My experience of stain and colour preparation is that the ingredients for=
=3D
the colour are melted together and then rapidly cooled either on a very co=
=3D
ld surface or in a water bath before being water-ground. The latter in a Ba=
=3D
ll Mill.
> Micro-encapsulation does involve coating grains with an inert material wh=
=3D
ich further Ball-milling could destroy, =3DA0 However the potential hazard =
wo=3D
uld be mainly at the point of milling, decreasing substantially with diluti=
=3D
on as the milled material is added to a slip or similar.
> Examination of MSDS of coloured slips and the like will demonstrate that =
=3D
ALL ingredients including water are included in the hazard calculation.
> Dry Clay dust is substantially more hazardous than slips containing small=
=3D
percentages of stain.
> Anyone who eats, drinks or smokes (all of which involve hand to mouth con=
=3D
tact) in a clay workshop has only themselves to blame for subsequent proble=
=3D
ms.
>
> Steve M
>
>
> Steve Mills
> Bath
> UK
> www.mudslinger.me.uk
> Sent from my iPod
>
>
> On 27 May 2012, at 21:30, Ben Morrison wrote:
>
>> Well the particles of stain should be harder than the balls in the ball =
=3D
mill. However ball milling an encapsulated stains such as the yellow yttriu=
=3D
m, or praesidium stains could break apart the encapsulation making the toxi=
=3D
c materials readily available to contaminate the potters body or the bodies=
=3D
of the customer much more easily.
>>
>> -Ben
>>
>> From: Steve Mills
>> To: Clayart@LSV.CERAMICS.ORG
>> Sent: Sunday, May 27, 2012 10:01 AM
>> Subject: Re: Yellow Terra Sig.
>>
>> Dipping my toe in as a non terra-sig person, my usual answer to relative=
=3D
ly coarse materials is to resort to the ball mill. Some of my glazes are mi=
=3D
lled to finer than 250 mesh to aid adhesion.
>> Perhaps milling the colour finer would restore the balance.
>>
>> Steve M
>>
>>
>> Steve Mills
>> Bath
>> UK
>> www.mudslinger.me.uk
>> Sent from my iPod
>>
>>
>> On 26 May 2012, at 05:37, Vince Pitelka wrote:
>>
>> > Potterybyjohn wrote:
>> > "I noticed that the CAD video today mentioned adding stain to terra si=
=3D
g.
>> > Briefly, they said they get the specific gravity lower to accept the a=
=3D
dded
>> > stain. I think I need to try this myself."
>> >
>> > John -
>> > This seems completely counterintuitive, but that doesn't mean that it =
=3D
won't
>> > work. =3DA0The stain particles are like giant boulders compared to the=
r=3D
efined
>> > clay platelets in the terra sig. =3DA0It seems like lowering the speci=
fi=3D
c
>> > gravity would cause them to settle out super fast. =3DA0If you do try =
th=3D
is,
>> > please report back to us about the results.
>> > - Vince
>> >
>> > Vince Pitelka
>> > Appalachian Center for Craft
>> > Tennessee Tech University
>> > vpitelka@dtccom.net
>> > http://iweb.tntech.edu/wpitelka/
>>
>>
--=3D20
----------------------------------------------------------
| |
|
