Stephani Stephenson on fri 5 oct 01
Jessamyn wrote
"Has anyone ever tried using plasticine (modelling clay) instead of clay
for making tiles (etc.) for plaster casting?"
Jessamyn
Plasticine will release quite easily and readily from plaster mold.
no need to use a release agent
Stephani Stephenson
Carlsbad, CA
Jessamyn Sommers on fri 5 oct 01
Has anyone ever tried using plasticine (modelling clay) instead of clay
for making tiles (etc.) for plaster casting? I had the inspiration and have
modelled some really nice tiles (very tidy process, actually, very
satisfying), now I am afraid to cast them as I'm unsure if they will release
properly. I am going to make some trial tiles using various substances to
see what will work best, I'm trying spraying with oil, other oily
lubricants, and talcum to see if they help. Has anyone tried this before or
does anyone have any ideas? Just thought I'd ask before I have a go, thanks
for your help,
Jessamyn, in Cork, Ireland
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
vince pitelka on sat 6 oct 01
> The stuff I've used worked fine for plaster casting without another
> release agent. I saw a recipe once for home made plasticine. I don't
> remember the specifics, but it called for clay plus oil (motor oil, as I
> recall). With care you should be able to get a number of plaster casts
> from your original.
You can make your own plasticene clay, combining dry powdered clay (ball
clay or goldart, it doesn't matter), microcrystaline wax (from art supply
that sells foundry supplies) and oil. If you want a cleaner plasticene you
can use mineral oil, but most people just use motor oil. If you can find a
supplier that will sell you mineral oil in quantity, I would go that route.
Heat it all up in a big cauldron or stock pot, but watch the heat. Do not
turn it up higher than 250 degrees, just like the wax pot for doing wax
resist.
I do not remember the specific proportions, so you will have to do some
experimentation. As you may know, when you buy plasticene from an art
supply store, they sell it in varying degrees of hardness. That is due to
the proportion of clay to oil to wax, so you will be able to do some fine
tuning to get the plasticene which works best for your own needs.
And as Jan stated above, you do not need to use any release compound. Since
plasticene is oil-base, the plaster will not stick. All the old time
sculptors doing commemorative statuary of Civil War heroes did all the fine
surface detail in plasticene, and then plaster molds were lifted from the
original. About ten years ago I visited a friend who was working at Tallix
Art Foundry in Cold Spring NY up on the Hudson River, and they had an old
master sculptor doing an equestrian figure (two times life size) - a Civil
War memorial for some little town. He was doing the detail work in
plasticene. The work was stiff and conservative, and absolutely fascinating
to see.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Jan McQueary on sat 6 oct 01
The stuff I've used worked fine for plaster casting without another
release agent. I saw a recipe once for home made plasticine. I don't
remember the specifics, but it called for clay plus oil (motor oil, as I
recall). With care you should be able to get a number of plaster casts
from your original.
Jan McQueary
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/web/.
Nanci Bishof on sat 6 oct 01
I use plasticine all the time. It works better than clay as it does not dry
out and remains flexible when releasing from the mold. Works well for latex
molds too.
nanci
Patrick Logue on sat 6 oct 01
Hi Jessamyn
I modeled a few tiles with oil based clay. I didnt
like it. It is difficult to release(the molds i made
still have little bits of it in the corners. Also
every time I reclaimed it, I ended up with pieces of
plaster in it that I couldnt seem to get rid of.
Iwent back to just using my regular clay. I just ball
it up and throw it away when I pull it out of the new
mold.It releases wonderfully, no clean up at all on
the mold.
Good luck
Pat Logue
--- Jessamyn Sommers wrote:
> Has anyone ever tried using plasticine (modelling
> clay) instead of clay
> for making tiles (etc.) for plaster casting? I had
> the inspiration and have
> modelled some really nice tiles (very tidy process,
> actually, very
> satisfying), now I am afraid to cast them as I'm
> unsure if they will release
> properly. I am going to make some trial tiles using
> various substances to
> see what will work best, I'm trying spraying with
> oil, other oily
> lubricants, and talcum to see if they help. Has
> anyone tried this before or
> does anyone have any ideas? Just thought I'd ask
> before I have a go, thanks
> for your help,
> Jessamyn, in Cork, Ireland
>
>
>
>
>
_________________________________________________________________
> Get your FREE download of MSN Explorer at
> http://explorer.msn.com/intl.asp
>
>
______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change
> your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots@pclink.com.
__________________________________________________
Do You Yahoo!?
NEW from Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month.
http://geocities.yahoo.com/ps/info1
Robert Dye on sat 6 oct 01
I have successfully cast from a plasticine model with no problems. There
are many brands of modeling clay so I would recommend you make up a small
dummy tile, maybe 1 X 1 and cast it as a trial. If you have problems use a
couple coats of mold soap. I didn't find that necessary. Good Luck. Bob
Dye
Snail Scott on sat 6 oct 01
At 08:16 PM 10/5/01 +0000, you wrote:
> Has anyone ever tried using plasticine (modelling clay) instead of clay
>for making tiles (etc.) for plaster casting?
YES!
If you are merely making the original ('pattern') for
the plaster mold, plasticine is ideal. You need no
release agent. No firing is needed, so turn-around time
for new designs is reduced. And you get a much more
forgiving pattern. The pattern can be easily extracted,
and any undetected undercuts can be corrected in the
plaster. You have unlimited 'open' time for working the
material without concern for drying. Also, there are no
shrinkage or warping issues at the pattern stage - and
the shrinkage of the plaster is negligible. You need
only calculate the final shrinkage of the fired clay
itself. And the plasticine, though more expensive than
water-based clay, is reusable indefinitely.
-Snail
Ross Hartman on mon 8 oct 01
Jessamyn;
As a mold maker let me through my two cents worth in..
Plasticine (I use Plastalina) is used all the time (but not exclusively of course)
for modeling originals as a starting point. When I go through the process of
making a mold from a plasticine original I consider the cast from the plasticine
to be a first step. If you use that first cast to actually cast slip in you will
have a fairly inefficient mold because oil from the clay is absorbed by the
plaster and leaves a residue of oil.
What I do is to cast a plug of harder plaster (hydrocal or a mix of hydrostone and
plaster) into that mold so that I can do detail work on the plug and create a
better master mold. I may iterate through this process several times until I am
satisfied with the final mold. At that point I make a master of the master (or a
case mold or sometimes called blocks and cases) to produce production copies of
the mold for slip cast production.
At least you should be aware that the plasticine will leave an oily residue in the
surface of your plaster casting.
FWIW...
L8R/Ross
Jessamyn Sommers wrote:
> Has anyone ever tried using plasticine (modelling clay) instead of clay
> for making tiles (etc.) for plaster casting? I had the inspiration and have
> modelled some really nice tiles (very tidy process, actually, very
> satisfying), now I am afraid to cast them as I'm unsure if they will release
> properly. I am going to make some trial tiles using various substances to
> see what will work best, I'm trying spraying with oil, other oily
> lubricants, and talcum to see if they help. Has anyone tried this before or
> does anyone have any ideas? Just thought I'd ask before I have a go, thanks
> for your help,
> Jessamyn, in Cork, Ireland
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
Snail Scott on mon 8 oct 01
At 07:32 AM 10/8/01 -0500, Ross Hartman wrote:
>What I do is to cast a plug of harder plaster (hydrocal or a mix of
hydrostone and
>plaster) into that mold so that I can do detail work on the plug and create a
>better master mold. I may iterate through this process several times until
I am
>satisfied with the final mold. At that point I make a master of the master
(or a
>case mold or sometimes called blocks and cases) to produce production
copies of
>the mold for slip cast production.
This is a very professional approach to mold-making
for production. Anyone planning a major run of slip-
cast work can really benefit from this extra effort.
You may find it unnecessary for just 'knocking off'
a few things, but quality tools are usually worth it
in the long run, and a homemade mold is a tool, too.
Don't ignore the plaster itself, either. As Ross
observes, there are different sorts for different
purposes. For your final slip-casting mold, pottery
plaster will give optimum absorption, but for the
preliminary steps, casting plaster may be more
useful, and Hydrocal (a very hard plaster) can be
great for detailed carving. You can use one sort
for everything, but if you make a habit of mold-
making, the advantages of the various types will
become evident.
(I have noticed that the Frith book on mold-making
is now available in paperback. Its hardback price
was prohibitive, but I really recommend it now that
it's affordable.)
-Snail
Michael Wendt on mon 8 oct 01
To all who want to make molds:
I use clay, yes, real clay to make the first model. I construct a container
around the clay piece and pour #1 pottery plaster mixed as described 2:3
water to plaster and can cast directly from the mold once it is dry without
soap residue, oil or anything else left to spoil the casts. For small run
molds, it is very direct. I only make ultracal master molds for long
production run molds. Try it, you'll like it...
Regards,
Michael Wendt wendtpot@lewiston.com
Ross Hartman wrote:
Jessamyn;
As a mold maker let me through my two cents worth in..
Plasticine (I use Plastalina) is used all the time (but not exclusively of
course)
for modeling originals as a starting point. When I go through the process of
making a mold from a plasticine original I consider the cast from the
plasticine
to be a first step. If you use that first cast to actually cast slip in you
will
have a fairly inefficient mold because oil from the clay is absorbed by the
plaster and leaves a residue of oil.
Rose Pinkul on wed 10 oct 01
Hi
Use only mold soap or you will seal the surface of the plaster and the mold
will not absorb water evenly if at all. After the mold is made clean the inside
surface very gently with a soft brush and a little denatured alcohol . Mold soap
isn't expensive and you should be able to get it at your ceramic supplier.
Rose
Jessamyn Sommers wrote:
> Has anyone ever tried using plasticine (modelling clay) instead of clay
> for making tiles (etc.) for plaster casting? I had the inspiration and have
> modelled some really nice tiles (very tidy process, actually, very
> satisfying), now I am afraid to cast them as I'm unsure if they will release
> properly. I am going to make some trial tiles using various substances to
> see what will work best, I'm trying spraying with oil, other oily
> lubricants, and talcum to see if they help. Has anyone tried this before or
> does anyone have any ideas? Just thought I'd ask before I have a go, thanks
> for your help,
> Jessamyn, in Cork, Ireland
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
--
Rose Pinkul Originals
Beautifully sculpted dolls
Quality plaster molds
Website http://www.pinkul.com
Phone 828-652-7430
Fax 828-652-2171
| |
|
