Alan L. Parker II, AIA on thu 31 jul 97
I am currently working on making press molds for some high relief
architectural relief pieces for fireplace surrounds. What is the best
way to press in clay so that it fills into all the areas and doesn't
develop air bubbles. Also sometimes the pieces don't always want to
release real easy from the molds, any suggestions. Write to Ann at
c1pwd@MIDUSA.NET
Richard Aerni on fri 1 aug 97
Ann,
When I used to do architectural ceramics (including fireplace surrounds)
with my partners Michael Frasca and Allan Nairn, we would just press
(pound) the clay in with our hands (fists) to the bas relief molds. If
the molds had real deep relief and getting it in there was going to be
difficult, we'd work with wetter clay. If even that didn't work we
figured we'd made a bad mold. You can always trim and tool the results
when they're out of the molds and leatherhard. We used a heavily grogged
clay, and never found air bubbles to be a problem. To release the molded
bits, we'd take a sock, fill it with grog, tie it off, and dust the
relief molds with this before putting the clay in (kinda made us feel
like baseball pitchers hoisting the old rosin bag).
If you haven't done this before, my guess is that your major problem will
come in applying the molded bits to your background tile. Try to keep
the two clay parts at equal wetness, and make sure you use plenty of slip
to apply the bas relief bit to the clay tile. I've had some of my old
tile samples out in the garden in northern NY for over ten years now, and
that's the only change I've seen in them--a couple of the relief
elelments have popped off.
Good luck,
Richard Aerni
>
> ----------------------------Original message----------------------------
> I am currently working on making press molds for some high relief
> architectural relief pieces for fireplace surrounds. What is the best
> way to press in clay so that it fills into all the areas and doesn't
> develop air bubbles. Also sometimes the pieces don't always want to
> release real easy from the molds, any suggestions. Write to Ann at
> c1pwd@MIDUSA.NET
John H. Rodgers on wed 6 aug 97
-- [ From: John H. Rodgers * EMC.Ver #2.5.02 ] --
Alan, in working with high relief molds I have found that the use of air
pressure helps to remove the clay piece from the mold. A blast of air
through a small tip on an air nozzle, when directed at the edge of the clay
will more than likely pop it loose. Press molds such as those used on a RAM
press use air to loosen the clay from the mold. You may also need to tool
your mold some to get a clean release.
John Rodgers
That Old Alaskan - now a raisin in the sun.
-------- REPLY, Original message follows --------
Date: Thursday, 31-Jul-97 09:04 AM
From: Alan L. Parker II, AIA \ Internet: (c1pwd@midusa.net)
To: CLAYART LIST \ Internet: (clayart@lsv.uky.edu)
Subject: HIGH RELIEF PRESS MOLDS
----------------------------Original message----------------------------
I am currently working on making press molds for some high relief
architectural relief pieces for fireplace surrounds. What is the best way to
press in clay so that it fills into all the areas and doesn't develop air
bubbles. Also sometimes the pieces don't always want to release real easy
from the molds, any suggestions. Write to Ann at c1pwd@MIDUSA.NET
-------- REPLY, End of original message --------
LINDA BLOSSOM on thu 7 aug 97
In the past, I have always used talc to release molds. I sprinkle it on
with a sieve. I also use a lot of WD 40. I use this on my extruder dies
and barrel, on pvc pipe that I use to wrap clay for pedestals. I use it on
clay before pouring plaster over it for release. I use it on smoothing
tools, on anything plastic that I am going to press into clay. Actually, I
have found that it works well just to spray the slab of clay and then press
into it. I guess, I'll have to try it on molds or on the clay going into
the molds and see how it stacks up to talc.
Linda Blossom
2366 Slaterville Rd.
Ithaca, NY 14850
607-539-7912
blossom@lightlink.com
http://www.artscape.com
Dave & Mary Kuilema on fri 8 aug 97
I have also used WD 40 as a release agent, but I am more and more concerned
about the health problems associated with VOCs; - evaporating petroleum
distillates. I know that the printing industry leans more and more towards
soy-based inks to avoid the problems of VOCs.
Does anyone know what the long term health affects might be? I
wish that PAM was as good a mold release as WD 40, but it does not come
close.
trying to keep my windows open for ventillation in Michigan
Mary
Marni Turkel on sat 9 aug 97
With all of the talk about PAM versus WD40 to release the clay from press
molds it sounds as if an absorbent plaster is not necessarily important. I
was wondering what kind of plaster different people are using for the molds
and if there is compressed air running through them. I've been doing some
work with press molds for about a year, but am using pottery #1 and
counting on drying shrinkage to release the piece. It works fine, but takes
a little while. Now I'm wondering if hydrastone or ultracal molds with a
release agent would be a viable alternative for a longer wearing mold
without the addition of a compressed air release system. I'd appreciate
hearing any thoughts on the process.
Marni Turkel
Stony Point Ceramic Design
Santa Rosa, California
Joseph Herbert on sat 9 aug 97
A couple of things come to mind in relation to the mold release thread:
These days Aerosol spray cans are often powered by butane. This makes most
of these sprays good blow torch substitutes in an initiating flame is
supplied. Further, the butane is heavier than air and could collect and flow
someplace to ignite if enough is sprayed around. Second, Talc is a close
mineral relative of asbestos - and often contains some. Sifting it through
the air onto a surface probably adds a needless additional worry to our ever
present and increasing dust guilt burden. Third, in my travels, I have
noticed that potters tend to inhabit the basements of old buildings. What do
we find in the basements of many old buildings? Asbestos insulated piping.
Yes, I know that Bernard Leach smoked asbestos and licked lead pipes and
lived for over 80 years, but I m not as tough as he. OK?
I do have a weighing balance calibrated with just over two hundredths of a
pound as the smallest units. This is not as helpful as you might think since
my glaze recipes are in drams, gills, hogsheads, and slugs. I am intending
to convert the volume measures to yogurt cups, the new standard of measure at
my house. Have to wait til my slide rule gets back from the shop.
Joseph Herbert
JJHerb@aol.com
Ric Swenson on sun 10 aug 97
>----------------------------Original message----------------------------
>A couple of things come to mind in relation to the mold release thread:
> These days Aerosol spray cans are often powered by butane. This makes most
>of these sprays good blow torch substitutes in an initiating flame is
>supplied. Further, the butane is heavier than air and could collect and flow
>someplace to ignite if enough is sprayed around. Second, Talc is a close
>mineral relative of asbestos - and often contains some. Sifting it through
>the air onto a surface probably adds a needless additional worry to our ever
>present and increasing dust guilt burden. Third, in my travels, I have
>noticed that potters tend to inhabit the basements of old buildings. What do
>we find in the basements of many old buildings? Asbestos insulated piping.
> Yes, I know that Bernard Leach smoked asbestos and licked lead pipes and
>lived for over 80 years, but I m not as tough as he. OK?
>
>I do have a weighing balance calibrated with just over two hundredths of a
>pound as the smallest units. This is not as helpful as you might think since
>my glaze recipes are in drams, gills, hogsheads, and slugs. I am intending
>to convert the volume measures to yogurt cups, the new standard of measure at
>my house. Have to wait til my slide rule gets back from the shop.
>
>Joseph Herbert
>JJHerb@aol.com
----reply-----------------------reply--------------------reply------------------
Joseph,
Hey ...you write your own stuff? Not too shabby. !! I always enjoy a
smattering of sarcasm and that kind of humor just seems to fit some of the
threads that pop up here now and again.
..........and hey....I had NO IDEA that Leach smoked asbestos......he was
rumored to hang about in cellars a lot.....but I had no idea he INHALED???
......and used asbestos containing TALC too.....right??
The Slide rule was a nice touch....
"Keep those cards and letters coming in folks....."
Happy potting all.
Ric
Ric Swenson, Bennington College, Route 67-A, Bennington Vermont 05201-6001.
(802) 442-5401 x 262 fax x 237 or fax direct to: (802) 442-6164
rswenson@bennington.edu
John H. Rodgers on mon 11 aug 97
-- [ From: John H. Rodgers * EMC.Ver #2.5.02 ] --
Joseph Herberts comments in this post brought to mind some things that
artists of all stripes should be aware of and take precautions for and
against.
Regards butanes flamability and its heavier than air property - this applies
to a number of volatile liquids that are often found in an art studio. I use
things like MEK (methylethelketone) acetone, naptha, toluol, tolulene,
denatured alcohol, to name just a few. They all serve a purpose in the many
things I do in the studio. And they are all very volatile, flammable, and
fumes are heavier than air. And the problem with them is that if they are
used in proximity to an open flame there is high likelyhood of an explosion
occuring.
Most of us are cautious about lighting a torch or what ever with a can of
flammable material on the work table, but most people don't pay much
attention to where the furnace or the hot water tank is located. There-in
lies the problem. Typical gas hot water heater installations are such that
the heater sits on the floor. The design of the units is such that the flame
is protected from the consumer - or the consumer is protected from the flame
- but none-the-less fumes drifting across the floor can be drawn inside the
air ports which provide combustion air to the flame. When that happens, BOOM
!!
This is a very big issue. I have personally witnessed engineering testing
of gas hot water heaters and seen the explosion occur repeatedly under test
conditions. Its quite a thing to see a bit of gasoline poured on the floor
in the middle of a room some good distance from the hot water heater closet,
and several minutes later hear a loud "Whump" and see the door to the heater
closet blow open and a flash of flame blow into the room.
The solution seems to be, at least in part, to have the hot water heater
installed 18 inches above the floor, above the level of the fumes. As I said
this is only part of the solution. A really good venting system is a must.
It should involve a positive air flow that continually dilutes with fresh
air the existing air in a room (and any fumes contained therein). There are
other things involved. Code compliance is another thing.
Related is how the furnace is operated. A forced air unit is a closed
system to prevent combustion fumes from mixing with the breathable air in a
space. But how the air moves in a room can affect the direction that
volatile, flammable, fumes move and thereby could present a problem with a
hot water heater. This should also be considered.
The beginning of safety is to become aware, then take steps to eliminate
hazards, then deal with installations themselves.
Hope this little fire safety tidbit helps some fellow clayartist.
John Rodgers
An Old Alaska Sourdough
Question of the week......"Where the h..... is Chicken, Alaska?"
-------- REPLY, Original message follows --------
Date: Saturday, 09-Aug-97 07:35 PM
From: Joseph Herbert \ America On-Line: (JJHerb)
To: CLAYART LIST \ Internet: (clayart@lsv.uky.edu)
Subject: Re: high relief press molds
----------------------------Original message----------------------------
A couple of things come to mind in relation to the mold release thread:
These days Aerosol spray cans are often powered by butane. This makes most
of these sprays good blow torch substitutes in an initiating flame is
supplied. Further, the butane is heavier than air and could collect and
flow someplace to ignite if enough is sprayed around. Second, Talc is a
close mineral relative of asbestos - and often contains some. Sifting it
through the air onto a surface probably adds a needless additional worry to
our ever present and increasing dust guilt burden. Third, in my travels, I
have noticed that potters tend to inhabit the basements of old buildings.
What do we find in the basements of many old buildings? Asbestos insulated
piping.
Yes, I know that Bernard Leach smoked asbestos and licked lead pipes and
lived for over 80 years, but I m not as tough as he. OK?
I do have a weighing balance calibrated with just over two hundredths of a
pound as the smallest units. This is not as helpful as you might think
since my glaze recipes are in drams, gills, hogsheads, and slugs. I am
intending to convert the volume measures to yogurt cups, the new standard of
measure at my house. Have to wait til my slide rule gets back from the
shop.
Joseph Herbert
JJHerb@aol.com
-------- REPLY, End of original message --------
Louis Katz on mon 11 aug 97
I am not sure if this will work with your molds and have not been folling
the thread. But.
We use corn starch as a release. Baby powder bottles make great
applicators for this stuff in our studio. I avoid using the actual baby
powder as it is fahrschtunkineh (stinky). BTW, we just use water on our
babies butt, no trash, no rash.
Makin video before the semester starts.
Louis
CDANIELLE on wed 13 aug 97
I was told that WD 40 is fish oil. I don't know if that's true or not,
you might want to check it out.
Dave & Mary Kuilema wrote:
>
> ----------------------------Original message----------------------------
> I have also used WD 40 as a release agent, but I am more and more concerned
> about the health problems associated with VOCs; - evaporating petroleum
> distillates. I know that the printing industry leans more and more towards
> soy-based inks to avoid the problems of VOCs.
> Does anyone know what the long term health affects might be? I
> wish that PAM was as good a mold release as WD 40, but it does not come
> close.
> trying to keep my windows open for ventillation in Michigan
> Mary
Tom Buck on thu 14 aug 97
WD40 is a petroleum distillate that contains easily volatilized aryl
compounds, eg, benzene, others, that are known to be carcinogenic. To use
WD40 on a daily basis even in a well ventilated room would be seeking a
shorter lifespan. Daily use of WD40 should only be conducted under a fume
hood such as are used in chem labs.
Tom Buck )
Hamilton, Ontario, Canada
Louis Katz on fri 15 aug 97
In Thailand before they discovered that Deisel fuel worked and was
cheaper they used to use coconut oil as a release for clay on aluminum
molds. They would apply the coconut oil with a saturated rag. There is a
bit of footage on tile making in my video "Dankwean" on Thai pottery from
the village of Dankwean in Northeast Thailand.
Coconut oil can be had at health food stores. It goes rancid pretty
easily. Some people develop allergies to palm products. Crisco might work
the same.
Louis
Louis Katz
Texas A&M University Corpus Campus
lkatz@falcon.tamucc.edu
NEW WEBSITE:http://maclab.tamucc.edu/lkatz/lkatz/index.html
Carole Rishel on sat 16 aug 97
In a message dated 97-08-09 19:44:17 EDT, you write:
<< These days Aerosol spray cans are often powered by butane. >>
PAM does come in a non-aerosol pump bottle. If your grocery store doesn't
carry it that way - bug 'em!
<< I am intending
to convert the volume measures to yogurt cups >>
Now there's a measurement even I could understand!!
Carole Rishel
Bastrop, TX
CaroleER@aol.com
PS: Sorry Bill - but I really had to copy the messages this way! BTW, we
just drove through the south - probably past your house - I'm sorry I didn't
contact you! Next time!
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