arlene h. on mon 11 oct 99
I am trying to make a large sun face, like the mass produced ones. I tried
slabbing but got several cracks. Would coils work better? Should I be
adding grog to my clay? I used a clock cover for the face form and added
the rays to it. I let it dry slowly but ended up with scrap. Thanks.
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Christopher J. Anton on tue 12 oct 99
When working with large constructs I definitely prefer the reduced shrinkage
of a heavily grogged clay. I also find that building on a layer of grog
allows the form to shift with less stress from resistance.
- Chris
Jim Brooks on tue 12 oct 99
Arlene..maybe you should try using paper clay for your big sun faces. I
think that would end your cracking/breakage problem......Jim
Mark & Pauline Donaldson-Drzazga on tue 12 oct 99
----- Original Message -----
From: arlene h.
To:
Sent: 11 October 1999 16:30
Subject: large handbuilding
> ----------------------------Original message----------------------------
> I am trying to make a large sun face, like the mass produced ones. I
tried
> slabbing but got several cracks. Would coils work better? Should I be
> adding grog to my clay? I used a clock cover for the face form and added
> the rays to it. I let it dry slowly but ended up with scrap. Thanks.
>
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
Dear Arlene,
if you use any method you prefer to make your sun face, making sure you have
placed it on top of newspaper several sheets thick as you make, then wrap
the piece in newspaper and then cover with plastic (thin bin-liner is best)
and leave for 4-5 days. The newspaper evens out the moisture levels
throughout the piece, and so lessens the possibility of cracking. Let it dry
on the newspaper (you can fire it off if it sticks) and fire as normal. I
use the newspaper trick constantly to make my huge chimney pots using
combinations of thrown, slabbed, coiled and extruded (static extrusions as
explained before), and I use bog standard terracotta and buff clays with
15% fine grog. It works for me.
Happy potting Marek http://www.moley.uk.com
zahidi neale on tue 12 oct 99
YES you should add grog, or use a handbuilding body that contains it. I use
Standard 239 Raku clay. The problem with large arched slab forms is that the
stress cracks are created by the middle of the high part wanting to lay down
to the level of the low rim that is supporting it. So support that arch ALL
the time. I made a plaster hump to do this while it dries over a period of
about 2 weeks. Then I fire it with several graduated posts under it, holding
the arch up. I'm sure there is an easier way, and would love to hear from
those in the know.
Zahidi in Slidell, LA
zahidi@gs.verio.net
http://homepages.msn.com/TimesSquare/zeeartist/index.html
-----Original Message-----
From: arlene h.
To: CLAYART@LSV.UKY.EDU
Date: Monday, October 11, 1999 10:31 AM
Subject: large handbuilding
----------------------------Original message----------------------------
I am trying to make a large sun face, like the mass produced ones. I tried
slabbing but got several cracks. Would coils work better? Should I be
adding grog to my clay? I used a clock cover for the face form and added
the rays to it. I let it dry slowly but ended up with scrap. Thanks.
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Cindy Strnad, Earthen Vessels Pottery on tue 12 oct 99
Arlene,
If you want to make the face thick, as many of those I've seen are, you'll
need a very groggy clay. Terra cotta is generally used for this type of
sculpture, but I expect stoneware would work. Dry the piece slowly, maybe in
a loose plastic bag as soon as it's hard enough to place it inside one
without damaging it. When you think it's bone dry, set it on top of the kiln
during a firing or two.
Fire slowly. You should keep it at just below boiling for several hours. I
set my kiln to hold at 190 F. for as long a soak period as I deem necessary,
depending upon the thickness of the piece. (I'm at 5,000 feet, so boiling
temperature is lower here.) You want to avoid turning the water left in the
thick walls of your piece into sudden steam, thus blowing up your work. If
you don't have that option, maybe set the kiln on low overnight with the lid
open. It doesn't take much to get a kiln up over the safe temperature, so
watch carefully.
After the soaking/drying period, fire slowly (maybe 150 degrees F/hour) up
to 500 F, which is the temperature at which chemically bound water will be
released. Once you've passed these hurdles, your piece is likely to survive.
It may take some experimenting. Good luck.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
David Bradley on tue 12 oct 99
If you are using a non-porous form to shape the "sun-face", that could be the
cause of your cracks. Use a cloth between the mold and the clay, or better
yet, make a plaster, or bisque mold to lay your slab into( I am assuming you
are laying the clay into a concave mold). If you are laying your slab over a
hump, or convex mold the same consideration applies. If the mold is
non-porous the clay will remain stuck to it while the upper surface begins to
dry, thereby causing cracks to occur as it wants to shrink but cannot. Hope
that helps.
Eydie DeVincenzi on tue 12 oct 99
------------------
Message text written by Ceramic Arts Discussion List
=3EI am trying to make a large sun face, like the mass produced ones. I
tried
slabbing but got several cracks. Would coils work better? Should I be
adding grog to my clay? I used a clock cover for the face form and added
the rays to it. I let it dry slowly but ended up with scrap. Thanks.
=3C
Had you thought about making a mold and casting it in plaster? You can
then pop out several suns and spend your artistic energy in modifying each
piece.
Eydie DeVincenzi
the Gallaghers on wed 13 oct 99
If you are laying slabs over a solid curved form you may be getting cracks
as the clay shrinks and cannot continue to fit the form. Try casting the
form in plaster and using the negative as your mold. It will shrink aways
from the sides and should lift or drop out.
Michelle
In Oregon
-----Original Message-----
From: Eydie DeVincenzi
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, October 12, 1999 11:58 AM
Subject: large handbuilding
----------------------------Original message----------------------------
------------------
Message text written by Ceramic Arts Discussion List
>I am trying to make a large sun face, like the mass produced ones. I
tried
slabbing but got several cracks. Would coils work better? Should I be
adding grog to my clay? I used a clock cover for the face form and added
the rays to it. I let it dry slowly but ended up with scrap. Thanks.
<
Had you thought about making a mold and casting it in plaster? You can
then pop out several suns and spend your artistic energy in modifying each
piece.
Eydie DeVincenzi
Nikom Chimnok on wed 13 oct 99
I have had extraordinary luck with slop-casting paperclay. I have used a
terra cotta slip containing 30% fine grog and sodium silicate, then added
paper mulch in a ratio of 2 slip to 1 paper, by volume, and poured it into a
form, like strap steel on a concrete floor over grog. A real thick
mix--slop, not slip. Then after it sets up to plastic clay consistency,
attached to it. From 1 to 2 inches thick, largest piece I've made is 16X32
inches, a major tile. This size was determined by the dimensions of the kiln
I was firing it in--I suspect I could go much larger. Terra sigged it and
fired it fast: 12 hours to Cone 04. No cracks.
For what it's worth,
Nikom
**************************************************************************
At 14:57 12/10/99 EDT, you wrote:
>----------------------------Original message----------------------------
>------------------
>Message text written by Ceramic Arts Discussion List
>>I am trying to make a large sun face, like the mass produced ones. I
>tried
>slabbing but got several cracks. Would coils work better? Should I be
>adding grog to my clay? I used a clock cover for the face form and added
>the rays to it. I let it dry slowly but ended up with scrap. Thanks.
><
>Had you thought about making a mold and casting it in plaster? You can
>then pop out several suns and spend your artistic energy in modifying each
>piece.
>
>Eydie DeVincenzi
>
>
John Fazzino on thu 14 oct 99
I would add grog to your clay and make sure there is paper between clay and
clock face. Use between 10 and 25%.
In a message dated 10/12/99 2:58:49 PM, E_DeVincenzi@compuserve.com writes:
<< ------------------
Message text written by Ceramic Arts Discussion List
>I am trying to make a large sun face, like the mass produced ones. I
tried
slabbing but got several cracks. Would coils work better? Should I be
adding grog to my clay? I used a clock cover for the face form and added
the rays to it. I let it dry slowly but ended up with scrap. Thanks.
<
Had you thought about making a mold and casting it in plaster? You can
then pop out several suns and spend your artistic energy in modifying each
piece.
Eydie DeVincenzi
>>
Phyllis E. Tilton on tue 19 oct 99
Arlene: Maybe someone else has answered you on the sun faces. I am waaaaay
behind in reading my messages. I have made many sunfaces. I found that I had
better luck(no cracks) if I drew a pattern, rays included, and cut around
that. I also made a round form out of clay and bisqued it. I put the round on
a plastic covered piece of wall board, and put a piece of drycleaner plastic
over the bisqued round. Then the rolled clay goes on top. The plastic lets me
lift the clay til I have it centered on the clay round. That's where the fun
begins-adding clay for puffed cheeks, cutting designs into the rays,
stretching that clay and whatever else you want to do to create the face.
Then, I let it dry slowly. One of the pizza places has these little plastic
things with legs to keep the lid from touching the pizza toppiing. I save
those and use them to protect pieces and let air circulate a bit. I use
A.R.T.'s orangestone clay for these and fire to ^6. It does darken with the
heat but I like that-adds to the contrast. Some people leave them out doors
the year around-in all kinds of weather- ice, snow,etc. One person called
wanting to know how to make it mossy. After seeing their garden, I concur
that it would enhance it but I'm not sure how to do that. Anyone have ideas
on that? Like putting it under moist shrubs facing north? I hope my input
will help.
Phyllis Tilton
Daisypet@aol,com
John Palmquist on wed 20 oct 99
Hi,
I know someone who "paints" plain yogurt on clay pots to incourage green
growth! She just puts the yogurt,with a paint brush, where she wants the
piece to mold. I have never tried this but I guess it makes sense! Good
luck-Diane
-----Original Message-----
From: Phyllis E. Tilton
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, October 19, 1999 5:02 PM
Subject: Re: large handbuilding
>----------------------------Original message----------------------------
>Arlene: Maybe someone else has answered you on the sun faces. I am waaaaay
>behind in reading my messages. I have made many sunfaces. I found that I
had
>better luck(no cracks) if I drew a pattern, rays included, and cut around
>that. I also made a round form out of clay and bisqued it. I put the round
on
>a plastic covered piece of wall board, and put a piece of drycleaner
plastic
>over the bisqued round. Then the rolled clay goes on top. The plastic lets
me
>lift the clay til I have it centered on the clay round. That's where the
fun
>begins-adding clay for puffed cheeks, cutting designs into the rays,
>stretching that clay and whatever else you want to do to create the face.
>Then, I let it dry slowly. One of the pizza places has these little plastic
>things with legs to keep the lid from touching the pizza toppiing. I save
>those and use them to protect pieces and let air circulate a bit. I use
>A.R.T.'s orangestone clay for these and fire to ^6. It does darken with the
>heat but I like that-adds to the contrast. Some people leave them out doors
>the year around-in all kinds of weather- ice, snow,etc. One person called
>wanting to know how to make it mossy. After seeing their garden, I concur
>that it would enhance it but I'm not sure how to do that. Anyone have ideas
>on that? Like putting it under moist shrubs facing north? I hope my input
>will help.
>
>Phyllis Tilton
>Daisypet@aol,com
>
the Gallaghers on wed 20 oct 99
Phyllis,
I heard once that you can encourage moss to grow by taking a small bit of
live moss and mixing it in a blender with yogurt. Pour this mixture over
anything you want moss to grow on and soon it will!
Michelle
In Oregon where it's not difficult at all to grow moss, on anything!!
-----Original Message-----
From: Phyllis E. Tilton
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, October 19, 1999 2:00 PM
Subject: Re: large handbuilding
>----------------------------Original message----------------------------
>Arlene: Maybe someone else has answered you on the sun faces. I am waaaaay
>behind in reading my messages. I have made many sunfaces. I found that I
had
>better luck(no cracks) if I drew a pattern, rays included, and cut around
>that. I also made a round form out of clay and bisqued it. I put the round
on
>a plastic covered piece of wall board, and put a piece of drycleaner
plastic
>over the bisqued round. Then the rolled clay goes on top. The plastic lets
me
>lift the clay til I have it centered on the clay round. That's where the
fun
>begins-adding clay for puffed cheeks, cutting designs into the rays,
>stretching that clay and whatever else you want to do to create the face.
>Then, I let it dry slowly. One of the pizza places has these little plastic
>things with legs to keep the lid from touching the pizza toppiing. I save
>those and use them to protect pieces and let air circulate a bit. I use
>A.R.T.'s orangestone clay for these and fire to ^6. It does darken with the
>heat but I like that-adds to the contrast. Some people leave them out doors
>the year around-in all kinds of weather- ice, snow,etc. One person called
>wanting to know how to make it mossy. After seeing their garden, I concur
>that it would enhance it but I'm not sure how to do that. Anyone have ideas
>on that? Like putting it under moist shrubs facing north? I hope my input
>will help.
>
>Phyllis Tilton
>Daisypet@aol,com
Janet Kaiser on wed 20 oct 99
-----Original Message-----
From: Phyllis E. Tilton
To: CLAYART@LSV.UKY.EDU
Date: 19 October 1999 22:00
Subject: Re: large handbuilding
>----------------------------Original message----------------------------
>Arlene: Maybe someone else has answered you on the sun faces. I am waaaaay
>behind in reading my messages. I have made many sunfaces. I found that I
had
>better luck(no cracks) if I drew a pattern, rays included, and cut around
>that. I also made a round form out of clay and bisqued it. I put the round
on
>a plastic covered piece of wall board, and put a piece of drycleaner
plastic
>over the bisqued round. Then the rolled clay goes on top. The plastic lets
me
>lift the clay til I have it centered on the clay round. That's where the
fun
>begins-adding clay for puffed cheeks, cutting designs into the rays,
>stretching that clay and whatever else you want to do to create the face.
>Then, I let it dry slowly. One of the pizza places has these little plastic
>things with legs to keep the lid from touching the pizza toppiing. I save
>those and use them to protect pieces and let air circulate a bit. I use
>A.R.T.'s orangestone clay for these and fire to ^6. It does darken with the
>heat but I like that-adds to the contrast. Some people leave them out doors
>the year around-in all kinds of weather- ice, snow,etc. One person called
>wanting to know how to make it mossy. After seeing their garden, I concur
>that it would enhance it but I'm not sure how to do that. Anyone have ideas
>on that? Like putting it under moist shrubs facing north? I hope my input
>will help.
>
>Phyllis Tilton
>Daisypet@aol,com
Phyllis,
Here in the UK where it is kind of damp anyway we use yoghurt spread
on sculptures as a "starter" for moss and lichen growth. As long as it is
not in direct hot sun this soon does the trick.
Janet Kaiser
The Chapel of Art, Home of The International Potters Path
Criccieth, GB-Wales, UK http://www.the-coa.org.uk
postbox@the-coa.org.uk
James Blossom on sat 23 oct 99
Hi Phyllis.
Try firing to cone 2 or so for mossy surfaces. If your clay does not
vitrify, it will absorb water. Soak the fired piece in a commercial plant
food solution, and voila'! You have a solar chia pet if you innocculate with
moss spoores. HTH
Mike Blossom
Sleeping Dog Designs
Albuquerque, NM
-----Original Message-----
From: Phyllis E. Tilton
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, October 19, 1999 2:16 PM
Subject: Re: large handbuilding
>----------------------------Original message----------------------------
>Arlene: Maybe someone else has answered you on the sun faces. I am waaaaay
>behind in reading my messages. I have made many sunfaces. I found that I
had
>better luck(no cracks) if I drew a pattern, rays included, and cut around
>that. I also made a round form out of clay and bisqued it. I put the round
on
>a plastic covered piece of wall board, and put a piece of drycleaner
plastic
>over the bisqued round. Then the rolled clay goes on top. The plastic lets
me
>lift the clay til I have it centered on the clay round. That's where the
fun
>begins-adding clay for puffed cheeks, cutting designs into the rays,
>stretching that clay and whatever else you want to do to create the face.
>Then, I let it dry slowly. One of the pizza places has these little plastic
>things with legs to keep the lid from touching the pizza toppiing. I save
>those and use them to protect pieces and let air circulate a bit. I use
>A.R.T.'s orangestone clay for these and fire to ^6. It does darken with the
>heat but I like that-adds to the contrast. Some people leave them out doors
>the year around-in all kinds of weather- ice, snow,etc. One person called
>wanting to know how to make it mossy. After seeing their garden, I concur
>that it would enhance it but I'm not sure how to do that. Anyone have ideas
>on that? Like putting it under moist shrubs facing north? I hope my input
>will help.
>
>Phyllis Tilton
>Daisypet@aol,com
gail sheffield on wed 24 nov 99
In October, Mark (Marek?) Donald suggested that the best way to keep large
freshly-made pieces from cracking was to wrap them in newspaper and then in
plastic and leave alone for several days. The newspaper is to even out the
moisture levels as the piece dries. Question: Should the newspaper be dry
or damp? Seems like dry newspaper would suck out the surface moisture too
quickly.
Gail Sheffield
Covington, LA
Mark & Pauline Donaldson-Drzazga on thu 25 nov 99
----- Original Message -----
From: gail sheffield
To:
Sent: 24 November 1999 14:03
Subject: Re: large handbuilding
> ----------------------------Original message----------------------------
> In October, Mark (Marek?) Donald suggested that the best way to keep large
> freshly-made pieces from cracking was to wrap them in newspaper and then
in
> plastic and leave alone for several days. The newspaper is to even out
the
> moisture levels as the piece dries. Question: Should the newspaper be
dry
> or damp? Seems like dry newspaper would suck out the surface moisture too
> quickly.
>
> Gail Sheffield
> Covington, LA
>
Hi, ( its Marek Boguslaw Jan Drzazga Donaldson, dad changed his Polish name
by deed poll), its Marek actually.
to get newspaper to stay put on a surface you might have to brush it with a
damp sponge. But no matter if the paper is dry as it redistibutes it and so
homogenises the clay throughout, and the newspaper does not suck the
moisture out at any noticeable speed, in some cases it can make it more
moist temporarily. Its also great to cover a join and then into the drier
I have to force dry my ware for volume reasons) and the newspaper protects
the joined clay. It works brilliantly when constructing using a variety of
making methods (slabbing, throwing and coiling etc.), the newspaper
equalises the moisture levels and takes care of the various stresses.
Happy potting Marek http://www.moley.uk.com
Dave Finkelnburg on thu 25 nov 99
Gail,
I noticed the original post also. I tried it with dry newspaper, here
in a very dry climate, in a dryer than usual fall. I've had FANTASTIC
results. Largest platter I made to date came out of the kiln with NO
cracks, a dozen smaller ones also came through uncracked. (Now, if I could
just get the form and the glazing down.......)
I also tried the newspaper on some cone 5 "porcelain" mugs and
candleholders with fairly thin handles. This seemed to stop some cracking
problems I had been having at the point of attachment.
I also used it on a pedestal and "platter" form for a sundial. The
pedestal varied from 3/4 to 1" thick. It seemed to dry fine.
Lately I've been using the newspaper on these pieces without the
plastic. It seems to be a surprisingly effective moisture barrier. I
haven't found the newspaper to be drying anything out too fast.
Dave Finkelnburg
-----Original Message-----
From: gail sheffield
To: CLAYART@LSV.UKY.EDU
Date: Wednesday, November 24, 1999 7:04 AM
Subject: Re: large handbuilding
>----------------------------Original message----------------------------
>In October, Mark (Marek?) Donald suggested that the best way to keep large
>freshly-made pieces from cracking was to wrap them in newspaper and then in
>plastic and leave alone for several days. The newspaper is to even out the
>moisture levels as the piece dries. Question: Should the newspaper be dry
>or damp? Seems like dry newspaper would suck out the surface moisture too
>quickly.
>
>Gail Sheffield
>Covington, LA
>
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