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making molds of fragile things?

updated thu 19 nov 98

 

Janet H Walker on mon 2 nov 98

I bought a beautiful and very fragile shell today whose
pattern I would dearly love to use on some pots. I'm
guessing that I get only one chance to make a mold from
this shell and then it is history.

What experience and wisdom do you have to share on this?

I have some notes on a post from Lowell Baker from a year
ago about using silicon caulk to get an impression from a
pattern that is already pressed into clay. But I'm afraid
that trying to press this shell into clay will just
destroy it outright.

I've seen rubber or latex mold stuff in catalogs (you brush
it on?) but don't know whether that would be intended for
this kind of use or not.

Ultimately, I'd like to get something from which I can
make a plaster stamp.

Ideas?
TIA
Jan Walker
Cambridge MA USA

Kelley Webb Randel on wed 4 nov 98

In a message dated 11/3/98 1:08:07 AM Central Standard Time,
jwalker@world.std.com writes:

<<
>>
Dear Jan,
I've made many plaster molds, but not always successfully. I would gently
press, or press the clay into the shell that has been treated with wd40 or
something like that. After removing the shell, use the indention in the clay
to create a plaster mold. This gives you a relief type of thing. You can
treat the plaster cast and then make another one if you wish, for the
positive/negative versions of the shell.
Good luck!
Kelley Webb Randel
Raku gddss@aol.com
where a guy in the studio has been making plaster casts of lizards from
Walmart!

Eydie DeVincenzi on wed 4 nov 98

------------------
Jan:

I had some beautiful shells which I lost during the moldmaking exercise
because I didn't see the =5Bsutle=5D negative angles. I just bought and =
read a
book called The Clay Lover's Guide to Making Molds by Pierce Clayton (a
Lark Ceramics Book, Asheville, NC). He has great hints:

1. Most complex pieces will require a 2-4 piece mold. To find out where
the mold lines need to be: Dim the lights in the room. Point a flashlight
at the largest surface area on the piece. Where the light shades, make
your mold line (that's the beginning of the negative angle). Reposition
the piece so that the shading is at the edge of the flashlight's light, and
repeat until the whole piece has been evaluated. He then walks through the
building of each of these molds.

2. The last chapter is about rubber molds.

3. The photos are very clear, numbered and referred to in the text.

Hope this helps. If you can't find the book, let me know. I bought my
copy at the Smithsoneon Renwick Gallery -- my favorite of the museums
because they feature American craftspeople.

Eydie DeVincenzi
Silver Spring, Maryland

Larry K Buell on wed 4 nov 98

Hello Janet,
I have made molds in the following manner: Spay object with cooking oil,
coat object with silicon caulk. Wait a day or so and peel off. Very
similar to what Mr. Baker is speaking of I believe. Don't know how fragile
your shell is but if it can withstand the peeling off this might work for
you. If this sounds interesting to you I give you more details.
Cheryl lbuell@dicksonstreet.com

----------
> From: Janet H Walker
> To: CLAYART@LSV.UKY.EDU
> Subject: making molds of fragile things?
> Date: Monday, November 02, 1998 1:23 PM
>
> ----------------------------Original message----------------------------
> I bought a beautiful and very fragile shell today whose
> pattern I would dearly love to use on some pots. I'm
> guessing that I get only one chance to make a mold from
> this shell and then it is history.
>
> What experience and wisdom do you have to share on this?
>
> I have some notes on a post from Lowell Baker from a year
> ago about using silicon caulk to get an impression from a
> pattern that is already pressed into clay. But I'm afraid
> that trying to press this shell into clay will just
> destroy it outright.
>
> I've seen rubber or latex mold stuff in catalogs (you brush
> it on?) but don't know whether that would be intended for
> this kind of use or not.
>
> Ultimately, I'd like to get something from which I can
> make a plaster stamp.
>
> Ideas?
> TIA
> Jan Walker
> Cambridge MA USA

Penny Hosler on wed 4 nov 98

Jan
The brush-on latex would work beautifully on your shell. Depending on its
shape you may have to make a little plaster "mother mold" to back the latex
with so it will keep its shape when you fill it with whatever. (actually
they have a product just for that purpose, but buying a gallon of it sorta
overkill for one shell) . If you want a really durable stamp I'd press it
little mid or high-fire clay into it when you're done to make your stamp.
Penny in WA
-----Original Message-----
From: Janet H Walker
To: CLAYART@LSV.UKY.EDU
Date: Monday, November 02, 1998 11:01 PM
Subject: making molds of fragile things?


----------------------------Original message----------------------------
I bought a beautiful and very fragile shell today whose
pattern I would dearly love to use on some pots. I'm
guessing that I get only one chance to make a mold from
this shell and then it is history.

What experience and wisdom do you have to share on this?

I have some notes on a post from Lowell Baker from a year
ago about using silicon caulk to get an impression from a
pattern that is already pressed into clay. But I'm afraid
that trying to press this shell into clay will just
destroy it outright.

I've seen rubber or latex mold stuff in catalogs (you brush
it on?) but don't know whether that would be intended for
this kind of use or not.

Ultimately, I'd like to get something from which I can
make a plaster stamp.

Ideas?
TIA
Jan Walker
Cambridge MA USA

leslie o'brien on wed 4 nov 98

Hi Janet,

There are many products on the market which make nice flexible molds.
One is called alginate which I think you can find at Art Supply
Warehouse, or perhaps even Michaels (the craft store). Another is a
two part rubber mold mix called "Pour-a-mold" 800-251-7642 company is
named Synair. I think they are in Tennessee somewhere. I have used the
S333 Thixotropic mix for taking molds of large busts and it is great.
Very strong and flexible at the same time.
There is also Peter's Sculpture Source in NYC 212-777-1079 which has a
variety of products. Call for a catalog.
I'm sure there are probably sources closer to where you are, you may
have to get on the horn and call around.
If it were me, I would do a test first on something you don't care for
as much as the shell, and then go from there.
Leslie in Providence

Darrell Gargus on wed 4 nov 98

Jan-
This is just an idea, I have never done this, but if you want to keep
the shell, how about putting it in some really runny clay. As it starts
to set up you can gently pull the shell out and hopefully still have the
pattern impression and the shell.
It is just a thought and maybe someone else has a better idea.
Becky

Janet H Walker wrote:
>
> ----------------------------Original message----------------------------
> I bought a beautiful and very fragile shell today whose
> pattern I would dearly love to use on some pots. I'm
> guessing that I get only one chance to make a mold from
> this shell and then it is history.
>
> What experience and wisdom do you have to share on this?
>
> I have some notes on a post from Lowell Baker from a year
> ago about using silicon caulk to get an impression from a
> pattern that is already pressed into clay. But I'm afraid
> that trying to press this shell into clay will just
> destroy it outright.
>
> I've seen rubber or latex mold stuff in catalogs (you brush
> it on?) but don't know whether that would be intended for
> this kind of use or not.
>
> Ultimately, I'd like to get something from which I can
> make a plaster stamp.
>
> Ideas?
> TIA
> Jan Walker
> Cambridge MA USA

Cheryl Sculley on thu 5 nov 98

Jan,

Synair Corp. is in Chattanooga, Tennessee. Address: 2003 Amnicola Hwy
37406. Phone: 1-423-698-8801. Ask for Stan. He was a great help when I
purchased my Pour-a-mold.

Cheryl in Chattanooga, cjsculley@mindspring.com
-----Original Message-----
From: Janet H Walker
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, November 03, 1998 2:01 AM
Subject: making molds of fragile things?


----------------------------Original message----------------------------
I bought a beautiful and very fragile shell today whose
pattern I would dearly love to use on some pots. I'm
guessing that I get only one chance to make a mold from
this shell and then it is history.

What experience and wisdom do you have to share on this?

I have some notes on a post from Lowell Baker from a year
ago about using silicon caulk to get an impression from a
pattern that is already pressed into clay. But I'm afraid
that trying to press this shell into clay will just
destroy it outright.

I've seen rubber or latex mold stuff in catalogs (you brush
it on?) but don't know whether that would be intended for
this kind of use or not.

Ultimately, I'd like to get something from which I can
make a plaster stamp.

Ideas?
TIA
Jan Walker
Cambridge MA USA

Tracy Jane Jacobs on thu 5 nov 98

Hi Janet,
As a sculptor I use mold rubbers all the time, and I would say that would
be the best way to cast a fragile shell. Latex is cheap but time
consuming, you have to put on 12 layers, the last six with strips of
cloth, and let them dry in between
that takes forever. I usually use polytek's 74-30.It is not that
expensive and is very versatile. I usually pour it on. You can bury half
the shell in soft clay, then cover the open half with saran wrap and a
half inch slab of soft clay, build a fence and pour a plaster
mother-mold.Leave a hole to pour your rubber through the plaster part of
the mold. Take off the plaster when it sets up and remove the clay
slab(keep the shell buried halfway)and the saran wrap. Put the plaster
back in place and seal it to the clay base with fresh plaster.(Poly 74-30
leaks like crazy. You can't contain it with just clay like you can with
plaster. Next pour the rubber, you mix it in two parts by weight. It sets
in 24 hours, then you turn the whole thing over, remove all the clay and
reapeat the process on the other side. This time you have to leave two
holes, one to pour your model material into the cavity left by the shell.
This will give you a whole solid shell. If you just need a relief of one
side to pour plaster on, you would probably not need a plaster mother
mold, you could just make a cast with the rubber by pouring it over the
side you like (with the other side buried in clay) You will need some
poly release spray for a parting compound too. I have cast shells before
with success using poly 74-30, but they have a lot of other products too,
you might ask them what they would recommend. Synair is another good
company for mold rubbers, but I don't have their number handy.
Polytek's number is:610-559-8620:

Tracy
On Mon, 2 Nov 1998, Janet H Walker
wrote:

> ----------------------------Original message----------------------------
> I bought a beautiful and very fragile shell today whose
> pattern I would dearly love to use on some pots. I'm
> guessing that I get only one chance to make a mold from
> this shell and then it is history.
>
> What experience and wisdom do you have to share on this?
>
> I have some notes on a post from Lowell Baker from a year
> ago about using silicon caulk to get an impression from a
> pattern that is already pressed into clay. But I'm afraid
> that trying to press this shell into clay will just
> destroy it outright.
>
> I've seen rubber or latex mold stuff in catalogs (you brush
> it on?) but don't know whether that would be intended for
> this kind of use or not.
>
> Ultimately, I'd like to get something from which I can
> make a plaster stamp.
>
> Ideas?
> TIA
> Jan Walker
> Cambridge MA USA
>

Marcia Selsor on thu 5 nov 98

Jan,
I just cast several shells in pottery plaster using WD-40 as the release.
-read it on Clayart as while ago. Works great. Also sprayed the jiffy
mixer with WD40 and it cleaned up perfectly. I was making a large mold
at the same time so I was mixing about 40 lbs. of plaster.
Marcia in Montana

Penny Hosler wrote:
>
> ----------------------------Original message----------------------------
> Jan
> The brush-on latex would work beautifully on your shell. Depending on its
> shape you may have to make a little plaster "mother mold" to back the latex
> with so it will keep its shape when you fill it with whatever. (actually
> they have a product just for that purpose, but buying a gallon of it sorta
> overkill for one shell) . If you want a really durable stamp I'd press it
> little mid or high-fire clay into it when you're done to make your stamp.
> Penny in WA
> -----Original Message-----
> From: Janet H Walker
> To: CLAYART@LSV.UKY.EDU
> Date: Monday, November 02, 1998 11:01 PM
> Subject: making molds of fragile things?
>
> ----------------------------Original message----------------------------
> I bought a beautiful and very fragile shell today whose
> pattern I would dearly love to use on some pots. I'm
> guessing that I get only one chance to make a mold from
> this shell and then it is history.
>
> What experience and wisdom do you have to share on this?
>
> I have some notes on a post from Lowell Baker from a year
> ago about using silicon caulk to get an impression from a
> pattern that is already pressed into clay. But I'm afraid
> that trying to press this shell into clay will just
> destroy it outright.
>
> I've seen rubber or latex mold stuff in catalogs (you brush
> it on?) but don't know whether that would be intended for
> this kind of use or not.
>
> Ultimately, I'd like to get something from which I can
> make a plaster stamp.
>
> Ideas?
> TIA
> Jan Walker
> Cambridge MA USA

S. Simpson on sat 7 nov 98

Hi Janet,
I saw you were having trouble with the clayarters
giving you advise on the making of a fine line
patterned shell. You will not have to lose this
if you find the right stuff as to say!!
I have donea little of this and have tried all
the afore mentioned substances, in fact I am still
waiting for a piece to come out of a soft type
por-a-mold substance. It's been one year since I
covered a piece with it.
I finally bit the bullet and asked for professional help and believe me it was w
I have never received anything that cheap in my life just by asking. It was like
And here is the best part, I was out of there in 15 minutes with a perfect copy.
These products are made by 3-M. and I'm sure you can't afford them for one piece
but give a dentist friend of yours a call. If you do enough of this give 3-M a c
Just thought as much help as clayarters have given me I could at least help them
Scott
ICQ#18246534
In Floydada, Texas
---------------------------Original message----------------------------
> I bought a beautiful and very fragile shell today whose
> pattern I would dearly love to use on some pots. I'm
> guessing that I get only one chance to make a mold from
> this shell and then it is history.
>
> What experience and wisdom do you have to share on this?
>
> I have some notes on a post from Lowell Baker from a year
> ago about using silicon caulk to get an impression from a
> pattern that is already pressed into clay. But I'm afraid
> that trying to press this shell into clay will just
> destroy it outright.
>
> I've seen rubber or latex mold stuff in catalogs (you brush
> it on?) but don't know whether that would be intended for
> this kind of use or not.
>
> Ultimately, I'd like to get something from which I can
> make a plaster stamp.
>
> Ideas?
> TIA
> Jan Walker
> Cambridge MA USA
>
>



-----
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Joseph Carames on tue 17 nov 98

I had computer problems so my response has been delayed


>I bought a beautiful and very fragile shell today whose
>pattern I would dearly love to use on some pots. I'm
>guessing that I get only one chance to make a mold from
>this shell and then it is history.
>
>What experience and wisdom do you have to share on this?
>
>I have some notes on a post from Lowell Baker from a year
>ago about using silicon caulk to get an impression from a
>pattern that is already pressed into clay. But I'm afraid
>that trying to press this shell into clay will just
>destroy it outright.
>
>I've seen rubber or latex mold stuff in catalogs (you brush
>it on?) but don't know whether that would be intended for
>this kind of use or not.
>
>Ultimately, I'd like to get something from which I can
>make a plaster stamp.
>
>Ideas?
>TIA
>Jan Walker
>Cambridge MA USA
>


Hi!

I don't know that much about mold making but this occurs to me.

I am going under the assumptions:
a) the shell is small, maybe a few inches around,
and
b) the surface you want to replicate is the outside surface.

make a thick slurry, be sure it is of even consistency, float the shell
on the surface of the slurry press it in to the depth you want don't let
it get covered.

once it is in position let it sit there til the clay dries around it and
it should come out easily maybe coat the shell with something so it
doesn't stick to the clay.

Hopefull it won't get too stressed and it wil last after the impression
is made.


good luck I am going to follow the discussion I want to know how it goes.

Joseph Carames

J. Carl Meigs on wed 18 nov 98


Rubber would pick up the small details. Have you thought of dental alginate?
Expensive, but not as expensive as the quantities rubber seems to tome in.
Ask your dentist how it works or any metalcaster could tell you. You can get
a finely detailed copy in minutes. Normally it is used by dentists and
others for preparing body part casts: mouths for teeth, etc. Good for
making wax models for investment casting of small things. Sculptors use it
too, and it is available from sculpture supply houses.

Good luck.
Carl
Brooklyn, CT







At 10:12 PM 11/17/98 EST, you wrote:
>----------------------------Original message----------------------------
>I had computer problems so my response has been delayed
>> ----------------------------Original
>message----------------------------
>
>
>>I bought a beautiful and very fragile shell today whose
>>pattern I would dearly love to use on some pots. I'm
>>guessing that I get only one chance to make a mold from
>>this shell and then it is history.
>>
>>What experience and wisdom do you have to share on this?
>>
>>I have some notes on a post from Lowell Baker from a year
>>ago about using silicon caulk to get an impression from a
>>pattern that is already pressed into clay. But I'm afraid
>>that trying to press this shell into clay will just
>>destroy it outright.
>>
>>I've seen rubber or latex mold stuff in catalogs (you brush
>>it on?) but don't know whether that would be intended for
>>this kind of use or not.
>>
>>Ultimately, I'd like to get something from which I can
>>make a plaster stamp.
>>
>>Ideas?
>>TIA
>>Jan Walker
>>Cambridge MA USA
>>
>
>
>Hi!
>
>I don't know that much about mold making but this occurs to me.
>
>I am going under the assumptions:
>a) the shell is small, maybe a few inches around,
>and
>b) the surface you want to replicate is the outside surface.
>
>make a thick slurry, be sure it is of even consistency, float the shell
>on the surface of the slurry press it in to the depth you want don't let
>it get covered.
>
>once it is in position let it sit there til the clay dries around it and
>it should come out easily maybe coat the shell with something so it
>doesn't stick to the clay.
>
>Hopefull it won't get too stressed and it wil last after the impression
>is made.
>
>
>good luck I am going to follow the discussion I want to know how it goes.
>
>Joseph Carames
>
>
>
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