Tom Eastburn on sun 4 apr 10
Hi returning NCECA'ites and everyone else,
I need to make a plaster mold or two, using a new 25" metal child's =3D
saucer.
Any suggestions regarding the need for a release agent. I've used =3D
baking powder=3D20
on wooden molds, but do you suppose I need something on this metal, or =3D
will the
plaster shrink down enough to just release itself in time?
Thanks
Tom Eastburn, in the Black Hills of S. Dak.=3D
James Freeman on mon 5 apr 10
Tom...
Plaster sticks pretty well to metal, though it will (usually) pop off.
Also, I am pretty sure plaster expands rather than shrinks as it
cures.
My own method is NOT kosher in any way, and will earn me the ire of
the professional mold makers, but I share it nonetheless. The proper
mold release agent is mold soap, for many good reasons. Since I have
not had particularly good results with soap, I went with the heavy
artillery. I use an emulsion of 50% vaseline and 50% kerosene (diesel
fuel), well blended using a drill-mounted paint mixer. Paint it on
thinly, then wipe most of it off with paper towels.
The common, and surely valid, criticism of greasy or oily release
agents is that they contaminate the mold and cause absorbency
problems. I have never experienced this problem, however, even with
slip casting molds. While I am sure doing it "the right way" is
better, the vaseline/kerosene mix works very well.
Now a question for you, if I might: Where did you find a new metal
snow saucer? I have been looking for one for years, but all I can
find are plastic saucers with handles molded in.
...James
James Freeman
"All I say is by way of discourse, and nothing by way of advice. I
should not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/resources
On Mon, Apr 5, 2010 at 1:56 AM, Tom Eastburn wrote:
> Hi returning NCECA'ites and everyone else,
> I need to make a plaster mold or two, using a new 25" metal child's sauce=
=3D
r.
> Any suggestions regarding the need for a release agent. =3DA0I've used =
=3DA0b=3D
aking powder
> on wooden molds, but do you suppose I need something on this metal, or wi=
=3D
ll the
> plaster shrink down enough to just release itself in time?
>
> Thanks
>
> Tom Eastburn, in the Black Hills of S. Dak.
Angela Davis on mon 5 apr 10
HI Tom,
I use WD 40 or a rubbing of vegetabel oil on metal pans for release.
Works great.
Sounds like you'll have a nice big hump mold when your done.
Angela Davis
Homosassa FL
----- Original Message -----
From: "Tom Eastburn"
To:
Sent: Monday, April 05, 2010 1:56 AM
Subject: plaster mold release agent?
Hi returning NCECA'ites and everyone else,
I need to make a plaster mold or two, using a new 25" metal child's saucer.
Any suggestions regarding the need for a release agent. I've used baking
powder
on wooden molds, but do you suppose I need something on this metal, or will
the
plaster shrink down enough to just release itself in time?
Thanks
Tom Eastburn, in the Black Hills of S. Dak.=3D
Jeff Gieringer on mon 5 apr 10
Tom,
I made a plaster mold using the same type saucer about 2 months ago. I
also don't care much for mold soap. I sprayed mine with PAM cooking spray
and it released perfectly.
Jeff
----- Original Message -----
From: "Tom Eastburn"
To:
Sent: Monday, April 05, 2010 1:56 AM
Subject: plaster mold release agent?
Hi returning NCECA'ites and everyone else,
I need to make a plaster mold or two, using a new 25" metal child's saucer.
Any suggestions regarding the need for a release agent. I've used baking
powder
on wooden molds, but do you suppose I need something on this metal, or will
the
plaster shrink down enough to just release itself in time?
Thanks
Tom Eastburn, in the Black Hills of S. Dak.
Randall Moody on mon 5 apr 10
-----Original Message-----
From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of Tom Eastburn
Sent: Monday, April 05, 2010 1:56 AM
To: Clayart@LSV.CERAMICS.ORG
Subject: plaster mold release agent?
Hi returning NCECA'ites and everyone else,
I need to make a plaster mold or two, using a new 25" metal child's saucer.
Any suggestions regarding the need for a release agent. I've used baking
powder
on wooden molds, but do you suppose I need something on this metal, or will
the
plaster shrink down enough to just release itself in time?
Thanks
Tom Eastburn, in the Black Hills of S. Dak.=3D
I have had good luck with Murphy's Oil Soap. If you can find it in the
consistency of Vaseline, all the better. I haven't had much luck where I am
but I did find some when I was in Illinois. I am not even sure if they make
it like that anymore.
--Randall in Atlanta--
http://wrandallmoody.com/home.html
Jacqueline Miller on mon 5 apr 10
I am not an expert, but I would try a 50/50 solution of Murphy's oil
soap and water. Give it a thin coat and let it dry. Then repeat this
twice more. Perhaps you could try it with just a small amount of
plaster in the center as a test.
Jackie
On Mon, Apr 5, 2010 at 2:52 PM, James Freeman
wrote:
> Tom...
>
> Plaster sticks pretty well to metal, though it will (usually) pop off.
> Also, I am pretty sure plaster expands rather than shrinks as it
> cures.
>
> My own method is NOT kosher in any way, and will earn me the ire of
> the professional mold makers, but I share it nonetheless. =3DA0The proper
> mold release agent is mold soap, for many good reasons. =3DA0Since I have
> not had particularly good results with soap, I went with the heavy
> artillery. =3DA0I use an emulsion of 50% vaseline and 50% kerosene (diese=
l
> fuel), well blended using a drill-mounted paint mixer. =3DA0Paint it on
> thinly, then wipe most of it off with paper towels.
>
> The common, and surely valid, criticism of greasy or oily release
> agents is that they contaminate the mold and cause absorbency
> problems. =3DA0I have never experienced this problem, however, even with
> slip casting molds. =3DA0While I am sure doing it "the right way" is
> better, the vaseline/kerosene mix works very well.
>
> Now a question for you, if I might: =3DA0Where did you find a new metal
> snow saucer? =3DA0I have been looking for one for years, but all I can
> find are plastic saucers with handles molded in.
>
> ...James
>
> James Freeman
>
> "All I say is by way of discourse, and nothing by way of advice. =3DA0I
> should not speak so boldly if it were my due to be believed."
> -Michel de Montaigne
>
> http://www.jamesfreemanstudio.com
> http://www.flickr.com/photos/jamesfreemanstudio/
> http://www.jamesfreemanstudio.com/resources
>
>
>
>
> On Mon, Apr 5, 2010 at 1:56 AM, Tom Eastburn wrote:
>> Hi returning NCECA'ites and everyone else,
>> I need to make a plaster mold or two, using a new 25" metal child's sauc=
=3D
er.
>> Any suggestions regarding the need for a release agent. =3DA0I've used =
=3DA0=3D
baking powder
>> on wooden molds, but do you suppose I need something on this metal, or w=
=3D
ill the
>> plaster shrink down enough to just release itself in time?
>>
>> Thanks
>>
>> Tom Eastburn, in the Black Hills of S. Dak.
>
--=3D20
Jackie Miller
JackieAMiller@gmail.com
John Rodgers on mon 5 apr 10
Most of the time - when making plaster molds off a model - mold soap is
used. I typically use tincture of green soap cut 50/50 with water.
However, for something with a slick, hard, non-absorbant surface, an
oily release agent is needed. Plaster will stick like the very dickens
to metal, glaze, etc, anything non-porous. Molds on pourous surfaces are
one issue. Molds on a non-porous surface are another. For the metal, you
need an oily surface. This can be acconplished by spraying it with PAM,
or dissolving vaseline in turpenoid or mineral spirits and brushing it
on. When dry - the solvent evaporates, leaving the vaseline in a very
thin layer. When the plaster is poured against it - the vaseline will
coat the surface of the plaster, but will not penetrate it due to the
water in plaster. When the plaster begins to produce the heat of
hydration, te heat will soften the vaseline and it should just pop right
off - provided there are no undercuts. Use of vaseline or any oily agent
will contaminate the plaster, reducing or even stopping cold the water
absorbing quality of the plaster. However, using an oily release agent
on the plaster when forming the clay is not a problem unless you needd
the plaster to draw water from the clay. If that is the case, you will
need to make a few more steps - like cast plaster against the just made
mold to create a master, then cast another mold against the master -
using mold soap.. It starts getting involved.
John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com
Tom Eastburn wrote:
> Hi returning NCECA'ites and everyone else,
> I need to make a plaster mold or two, using a new 25" metal child's sauce=
r.
> Any suggestions regarding the need for a release agent. I've used bakin=
g powder
> on wooden molds, but do you suppose I need something on this metal, or wi=
ll the
> plaster shrink down enough to just release itself in time?
>
> Thanks
>
> Tom Eastburn, in the Black Hills of S. Dak.
>
>
Jacqueline Miller on tue 6 apr 10
John, That was very helpful to me too. Thank you. Jackie
On 4/5/10, John Rodgers wrote:
> Most of the time - when making plaster molds off a model - mold soap is
> used. I typically use tincture of green soap cut 50/50 with water.
> However, for something with a slick, hard, non-absorbant surface, an
> oily release agent is needed. Plaster will stick like the very dickens
> to metal, glaze, etc, anything non-porous. Molds on pourous surfaces are
> one issue. Molds on a non-porous surface are another. For the metal, you
> need an oily surface. This can be acconplished by spraying it with PAM,
> or dissolving vaseline in turpenoid or mineral spirits and brushing it
> on. When dry - the solvent evaporates, leaving the vaseline in a very
> thin layer. When the plaster is poured against it - the vaseline will
> coat the surface of the plaster, but will not penetrate it due to the
> water in plaster. When the plaster begins to produce the heat of
> hydration, te heat will soften the vaseline and it should just pop right
> off - provided there are no undercuts. Use of vaseline or any oily agent
> will contaminate the plaster, reducing or even stopping cold the water
> absorbing quality of the plaster. However, using an oily release agent
> on the plaster when forming the clay is not a problem unless you needd
> the plaster to draw water from the clay. If that is the case, you will
> need to make a few more steps - like cast plaster against the just made
> mold to create a master, then cast another mold against the master -
> using mold soap.. It starts getting involved.
>
> John Rodgers
> Clayartist and Moldmaker
> 88'GL VW Bus Driver
> Chelsea, AL
> Http://www.moldhaus.com
>
>
>
> Tom Eastburn wrote:
>> Hi returning NCECA'ites and everyone else,
>> I need to make a plaster mold or two, using a new 25" metal child's
>> saucer.
>> Any suggestions regarding the need for a release agent. I've used baki=
ng
>> powder
>> on wooden molds, but do you suppose I need something on this metal, or
>> will the
>> plaster shrink down enough to just release itself in time?
>>
>> Thanks
>>
>> Tom Eastburn, in the Black Hills of S. Dak.
>>
>>
>
--
Jackie Miller
JackieAMiller@gmail.com
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