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warping tiles

updated fri 20 jan 06

 

April Bishop on mon 23 jun 97

I'm a potter who decided to try my hand at tile making and I'm having a great
deal of trouble with warpage. I've been using my favorite cone 5 clays and
glazes which work great for pottery but warp as tiles. Are you not supposed to
fire tiles this high? Before I switch to cone 05 glazes, is there anything that
can be done to prevent warping? I've been drying the tiles slowly and on sheets
of drywall. My firings are at slow speed and they all still warp. They curl
under and even one side may sometimes shrink while the other sides don't and it
looks more like a trapezoid than a square.

Help. Help.

April
abishop@interserv.com

dunc lee mark mackenzie amy on tue 24 jun 97

>Sender: Ceramic Arts Discussion List
>From: April Bishop
>Subject: warping tiles
>To: Multiple recipients of list CLAYART
>-------------------------------------------------------------------------
We have successfully produced tiles at cone 10, the process is easy but time
consuming. Instead of drywall we use anaconda board, (not sure of the
spelling; a fibrous press board used as soundproofing in construction). We
make a stack using plywood then anaconda, then tile. Separate the next
stack using kiln half bricks and repeat. Cover the whole thing with poly
overnight, then the next day flip the tiles individually and repeat the process.

Good Luck, Duncan and Lee
>----------------------------Original message----------------------------
>I'm a potter who decided to try my hand at tile making and I'm having a great
>deal of trouble with warpage. I've been using my favorite cone 5 clays and
>glazes which work great for pottery but warp as tiles. Are you not supposed to
>fire tiles this high? Before I switch to cone 05 glazes, is there anything
that
>can be done to prevent warping? I've been drying the tiles slowly and on
sheets
>of drywall. My firings are at slow speed and they all still warp. They curl
>under and even one side may sometimes shrink while the other sides don't and it
>looks more like a trapezoid than a square.
>
>Help. Help.
>
>April
>abishop@interserv.com
>


_-------------------------------------------------------------------------------

Paul Lewing on tue 24 jun 97

April,
Two things that may help with your warping problem.
First, a clay body that works well for throwing may not be ideal for
tile making. If your clay is a very plastic porcelain body, you'd
probably be better off with some grog in the body or a body that's a
litle closer to a white stoneware.
Second, it's important to know about the property of clay called
plastic memory. This means that if you bend clay in one direction when
it's wet, it will "remember" and bend back that direction when it
dries and when it's fired. So it's important to never warp your tile
when you take it off the slab roller. This means rolling it on a
sheet of paper or cloth (I use interfacing) and sliding it off the
roller bed onto a board. When you flip the tiles over before they're
dry, put a board on them and flip the whole thing rather than picking
them up and warping them.
I hope this helps.
Paul Lewing, Seattle

Marni Turkel on tue 24 jun 97

April,

In my quest for flat tiles, I tried a lot of things. After cutting neat
slabs off the top of a pug of commercial clay and rolling it out on the
slab roller I had tiles that dried beautifully between sheet rock. I had 6
by 6 squares that were beautiful coming out of the bisque, but out of cone
5 had a donut shaped depression perfectly centered and 1/4 inch deep, just
where the auger pattern from a pug mill would have been. After that, I
started cutting slabs of clay off the sides of the bag. That helped, but it
wasn't enough. The slabs cut from the outside of the pug seemed to work
pretty well, but the ones cut from the inside were determined to curve and
tweak.

The solution for me was to still cut the slab from the side of the pug, but
to throw it down on the table (repeatedly) with quite a bit of force
(alternating sides and turning) to line up the clay particles and get rid
of the auger memory. Don't bend the slab once it has been rolled, and dry
it between pieces of sheet rock (gypsum wall board).

Good luck.

Marni Turkel
Stony Point Ceramic Design
Santa Rosa, California

Eileen M Streeter on tue 24 jun 97


april... when we made tiles... just flat with no relief designs... we
dried them slowly between sheets of drywall that were cut into smaller
manageable pieces and wrapped the edges with masking tape (don't want to
contaminate the clay with plaster... if you're going to make lots of
tiles of a particular size... cut the boards accordingly... at times we
even stacked the tiles (alternating with drywall) two or three high...
weight keeps everything from warping... does take time to dry and the
inner ones longer than those on the edge... but it worked... do you
score the bottoms for? good luck!
eileen... art student... concentration in ceramics at unh...

On Mon, 23 Jun 1997, April Bishop wrote:

> ----------------------------Original message----------------------------
> I'm a potter who decided to try my hand at tile making and I'm having a great
> deal of trouble with warpage. I've been using my favorite cone 5 clays and
> glazes which work great for pottery but warp as tiles. Are you not supposed t
> fire tiles this high? Before I switch to cone 05 glazes, is there anything th
> can be done to prevent warping? I've been drying the tiles slowly and on shee
> of drywall. My firings are at slow speed and they all still warp. They curl
> under and even one side may sometimes shrink while the other sides don't and i
> looks more like a trapezoid than a square.
>
> Help. Help.
>
> April
> abishop@interserv.com
>

Paul Lewing on wed 25 jun 97

Marni Turkel wrote:

>
> The solution for me was to still cut the slab from the side of the pug, but
> to throw it down on the table (repeatedly) with quite a bit of force
> (alternating sides and turning) to line up the clay particles and get rid
> of the auger memory.

This is known as "inducing plastic amnesia".
Paul Lewing, Seattle

SALLY WILLS on thu 26 jun 97

April Bishop wrote:
>
> ----------------------------Original message----------------------------
> I'm a potter who decided to try my hand at tile making and I'm having a great
> deal of trouble with warpage. I've been using my favorite cone 5 clays and
> glazes which work great for pottery but warp as tiles. Are you not supposed t
> fire tiles this high? Before I switch to cone 05 glazes, is there anything th
> can be done to prevent warping? I've been drying the tiles slowly and on shee
> of drywall. My firings are at slow speed and they all still warp. They curl
> under and even one side may sometimes shrink while the other sides don't and i
> looks more like a trapezoid than a square.
>
> Help. Help.
>
> April
> abishop@interserv.comTry putting the tile in plastic sleeves open on two ends
wallboard. Flip and air them (pull the plastic away from the clay)
every two-four days - dry for approx 4-6 weeks depending on the
consistency of the temp and the humidity. Also the thickness of the
tile makes a difference in the warping. It can be done, I have 160 flat
tiles on a table somewhere in New Mexico.

Sarah

Nancy Carey on thu 26 jun 97

PS, I think the reason you score tiles on the back is that it allows the glue
you use to attach well to the tile and the wall.

Howard on thu 26 jun 97

Although I have not yet tried this, I have heard that paper clay is an
excellent medium for making tiles that do not warp. Paper clay is any clay
that you already use, with paper fiber mixed in. I am told it works for
reasons as follows... Uneven drying is the most common reason for tiles
warping, as one area of the clay shrinks more quickly than another area.
Paper fibers act as wicks, thus they will wick air into, and throughout the
clay body. Thus paper clay drys more evenly than standard clay ergo less
warping. I am told that the paper fiber adds significant dry strength to
the clay as well. Both of these factors are supposed to allow for the
ability to successfully make much larger tiles. Rosanne Gault wrote a book
out called "Paper Clay for Sculptors" which illustrates how you can make
your own paper clay. There are a few clay companies that are making paper
clay under a licence from Rosanne's company New Century Ceramics. I am
negotiating a licence at this time and hope to be making these paper clays
later this summer... Howard Axner

millie carpenter on fri 27 jun 97

this is one of the things that Jane Larson had us do, we formed the
tile by pounding the clay into a form then cut the large slab into the
size and shapes we needed/wanted. when the tiles had dried to point
that they were quite firm but not leather hard, they were firmly
slapped upside down on another ware board. this worked because her
tiles have an impressed design that goes below the surface of the tile,
if there was a raised surface this wouldn't work. the other thing that
she did was to provide us with ware boards of marine plywood. this
surface doesn't warp, bow, or distort,

> > The solution for me was to still cut the slab from the side of the pug, but
> > to throw it down on the table (repeatedly) with quite a bit of force
> > (alternating sides and turning) to line up the clay particles and

millie in maryland where if it gets any hotter i will be able to fire
without a kiln.

Wayne Bien on tue 26 jun 01


I am in the process of doing a ceramic tile project for a church school. =
I am using Standard Ceramics clay #420. I chose this clay body because I =
had done another tile mural with it and had good results.

This time the tiles are 6"X6" and 1/4" thick. I dried them on sheets of =
MDF board and there was no warping or cracking. They were bisque to ^06 =
again with good results. They were decorated with commercial underglaze =
and a clear glaze and fired to ^6. That is where the problem started. =
All of the tiles are warped. Each corner is pointing upward. When I =
bisque them and for the glaze fire the tiles were stacked on corner =
brackets 6 high in the kiln.=20

Any advice anyone can provide as to the cause of the warping will be =
greatly appreciated.

Wayne

CINDI ANDERSON on tue 26 jun 01


Hi Wayne
I have collected a bunch of advice on this topic (from this list and elsewhere).

http://www.bigceramicstore.com/Information/tip30.htm
Cindi

Wayne Bien wrote:

> I am in the process of doing a ceramic tile project for a church school I am using Standard Ceramics clay #420. I chose this clay body because I had done another tile mural with it and had good results.
>
> This time the tiles are 6"X6" and 1/4" thick. I dried them on sheets of MDF board and there was no warping or cracking. They were bisque to ^06 again with good results. They were decorated with commercial underglaze and a clear glaze and fired to ^6. That is where the problem started. All of the tiles are warped. Each corner is pointing upward. When I bisque them and for the glaze fire the tiles were stacked on corner brackets 6 high in the kiln.
>
> Any advice anyone can provide as to the cause of the warping will be greatly appreciated.
>
> Wayne

Terrance Lazaroff on tue 26 jun 01


Wayne;

Could be the clay was beginning to slump at the glaze temp. I suggest you
find the tile setter that work like a lean too. This type of setter gives
support up the middle and the sides.

Terrance
----- Original Message -----
From: "Wayne Bien"
To:
Sent: Tuesday, June 26, 2001 4:50 PM
Subject: warping tiles


I am in the process of doing a ceramic tile project for a church school. I
am using Standard Ceramics clay #420. I chose this clay body because I had
done another tile mural with it and had good results.

This time the tiles are 6"X6" and 1/4" thick. I dried them on sheets of MDF
board and there was no warping or cracking. They were bisque to ^06 again
with good results. They were decorated with commercial underglaze and a
clear glaze and fired to ^6. That is where the problem started. All of the
tiles are warped. Each corner is pointing upward. When I bisque them and for
the glaze fire the tiles were stacked on corner brackets 6 high in the kiln.

Any advice anyone can provide as to the cause of the warping will be greatly
appreciated.

Wayne

____________________________________________________________________________
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Paul Lewing on tue 26 jun 01


on 6/26/01 11:42 PM, CINDI ANDERSON at cindi@HOME.NET wrote:

> When I bisque them and for the glaze fire the tiles were stacked on corner
> brackets 6 high in the kiln.

Cindi,
By "corner brackets" do you mean those little blocks of mullite shelf
material that fit one under each corner and stack up? If so, I'd say
there's your problem. I think the tiles are sagging and you need to support
them in the middle during firing.
Paul Lewing, Seattle

Snail Scott on tue 26 jun 01


At 04:50 PM 6/26/01 -0400, you wrote:
All of the tiles are warped. Each corner is pointing upward.
>Wayne

This always seems to happen as a result of uneven drying.
The little suckers may look flat going into the kiln,
but there's tension in them set up when they were drying.
They were probably stiff enough by then to not warp visibly,
but the tension was there, ready to spoil your day.

My advice: Dry them very slowly, and weight them between
drywall if they are flat. Turn them upside down if you can,
so they don't acquire a tendency to warp up on the corners.
(If they do warp anyway, warping downward is much less
obvious on the final work!) ;)
-Snail

Rhonda Oldland on wed 27 jun 01


Corner brackets are not good for firing up to cone 6....they tend to sag in
the middle and curle on the upper corners. I fire mine either flat directly
on the kiln shelve or in a tile setter that you slide the tiles into.
I also bisque at a higher temp. Try going up a cone.
Did you use the same glaze with the other tile project?
I have found the results vary with bisque firing , glaze and this southern
humidity.
Rhonda

At 21:45 6/26/01 -0400, you wrote:
>Wayne;
>
>Could be the clay was beginning to slump at the glaze temp. I suggest you
>find the tile setter that work like a lean too. This type of setter gives
>support up the middle and the sides.
>
>Terrance
>----- Original Message -----
>From: "Wayne Bien"
>To:
>Sent: Tuesday, June 26, 2001 4:50 PM
>Subject: warping tiles
>
>
>I am in the process of doing a ceramic tile project for a church school. I
>am using Standard Ceramics clay #420. I chose this clay body because I had
>done another tile mural with it and had good results.
>
>This time the tiles are 6"X6" and 1/4" thick. I dried them on sheets of MDF
>board and there was no warping or cracking. They were bisque to ^06 again
>with good results. They were decorated with commercial underglaze and a
>clear glaze and fired to ^6. That is where the problem started. All of the
>tiles are warped. Each corner is pointing upward. When I bisque them and for
>the glaze fire the tiles were stacked on corner brackets 6 high in the kiln.
>
>Any advice anyone can provide as to the cause of the warping will be greatly
>appreciated.
>
>Wayne
>
>____________________________________________________________________________
>__
>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.
>
>___________________________________________________________________________
___
>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.
>
>

primalmommy on sun 28 apr 02


Try one layer of tiles between two layers of sheetrock/drywall. They
take a long time to dry, but they don't dry faster on one side or the
other causing it to shrink/curl in that direction. Also, I bought yards
of that fabric they use to make sheer curtains -- I use it for jelly
making, tofu making, and rolling clay slabs. Hem the edges and you can
throw it in the washer, even bleach if you do that.

I roll a slab on top of the fabric, then flip it onto another sheet of
fabric, and keep rolling... or use the potters guild's slab roller with
a bit of fabric above and below. The mesh is small enough not to leave
much pattern, and when you pick up the slabes to move/flip them around,
you pick them up by the cloth and they don't stretch so much. I have
seen potters use two rulers to pinch a slab across one end and lift it
for the saem reason.

I have also dried small numbers of tiles between thin sheets of
styrofoam like folks use in packing. I put a board or something onthe
top one. Styro or drywall, I take the top one off every few days to see
how it's going, and if they're stiff enough I turn them over... if you
want them to dry faster you can move them to a new dry sheet of drywall
and put a new dry one on top...

I never fire more than 3 deep, and glaze fire with those little
corner-holders that stack.

Good luck!

Kelly in Ohio
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Chris Jones on sun 28 apr 02


Has anyone ever tried a Radiant Heat Panel? Like the ones used in 'drop
ceilings'. I have a friend who uses one and I have tried it with total
success. I have also tried the sheetrock method and that is good too.
Thank you,
Chris Jones

Visit www.jonespottery.net

Michael Wendt on mon 16 jan 06


Wendy,
If you mean the tile is flat but no longer square then
the cause of the warping you describe depends upon when you are seeing it.
If it occurs during drying, one side of the tile is shrinking more than the
other, usually caused either by uneven drying or more moisture on a side due
to poor wedging (or pugging).
If the warping occurs only in the glaze firing, the usual cause is uneven
firing when one side is subjected to a higher cone than the other and
shrinks more. I find this most often occurs when the tile is fired very near
its peak firing temperature with an edge near the edge of the shelf since
that is usually when it is undergoing the most fired shrinkage while the
center lags and is cooler, shrinking less.
Wire wedging using stack and slam can sometimes help but the first choice is
to try a few different clay bodies and find one that doesn't warp under your
firing conditions.If you fire cone 5-6, find one with a slightly higher
firing range.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, Idaho 83501
USA
wendtpot@lewiston.com
www.wendtpottery.com
Wendy wrote:
Has anyone an idea why our tiles are warping sideways? We are using Cone 5
Plainsman clay (with grog), placing them on gypsum wallboard bats and
stacking them. We are keeping them uncovered otherwise in a cool garage.
No warping up and down but they are warping somewhat sideways. Ideas how to
stop this?

Wendy Kelsey on mon 16 jan 06


Has anyone an idea why our tiles are warping sideways? We are using Cone 5 Plainsman clay (with grog), placing them on gypsum wallboard bats and stacking them. We are keeping them uncovered otherwise in a cool garage. No warping up and down but they are warping somewhat sideways. Ideas how to stop this?


Wendy Kelsey
Operations Manager
Martini Ceramics
Custom Tile and Ceramic Arts
1272 Paradise Cove
Ferndale, WA 98248-9469
Telephone: 360-392-8607
Fax: 832-550-4856

William Melstrom on mon 16 jan 06


> Has anyone an idea why our tiles are warping sideways? We are using Cone
> 5 Plainsman clay (with grog), placing them on gypsum wallboard bats and
> stacking them. We are keeping them uncovered otherwise in a cool garage.
> No warping up and down but they are warping somewhat sideways. Ideas how
> to stop this?

Wendy, are you extruding your tiles from a pugmill nozzel? Or slicing tiles
from a pugged cube of clay?
If so, the pugmill auger, which is at an angle, is imparting a "diagonal
bias" to your clay. Clay memory makes the clay want to return to the
diagonal orientation that the auger imparted to the clay.
The only practical solution that really works, in my opinion, is to
RAM-press your tiles, or to switch to a dual-auger pugmill that has two
angled sets of blades that oppose each other.
William Melstrom

Warren Heintz on mon 16 jan 06


Try scoring them on the bottom. Notice how commerical tiles are fluted.

Wendy Kelsey wrote: Has anyone an idea why our tiles are warping sideways? We are using Cone 5 Plainsman clay (with grog), placing them on gypsum wallboard bats and stacking them. We are keeping them uncovered otherwise in a cool garage. No warping up and down but they are warping somewhat sideways. Ideas how to stop this?


Wendy Kelsey
Operations Manager
Martini Ceramics
Custom Tile and Ceramic Arts
1272 Paradise Cove
Ferndale, WA 98248-9469
Telephone: 360-392-8607
Fax: 832-550-4856

______________________________________________________________________________
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.




---------------------------------
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Suzanne Wolfe on tue 17 jan 06


Wendy,
Can you give us some details on how the tiles were formed?
Thanks,
Suzanne Wolfe

----- Original Message -----
From: Warren Heintz
Date: Monday, January 16, 2006 5:23 pm
Subject: Re: warping tiles
To: CLAYART@LSV.CERAMICS.ORG

> Try scoring them on the bottom. Notice how commerical tiles are
> fluted.
> Wendy Kelsey wrote: Has anyone an
> idea why our tiles are warping sideways? We are using Cone 5
> Plainsman clay (with grog), placing them on gypsum wallboard bats
> and stacking them. We are keeping them uncovered otherwise in a
> cool garage. No warping up and down but they are warping somewhat
> sideways. Ideas how to stop this?
>
>
> Wendy Kelsey
> Operations Manager
> Martini Ceramics
> Custom Tile and Ceramic Arts
> 1272 Paradise Cove
> Ferndale, WA 98248-9469
> Telephone: 360-392-8607
> Fax: 832-550-4856
>
> ______________________________________________________________________________
> 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.
>
>
>
> ---------------------------------
> Yahoo! Photos
> Got holiday prints? See all the ways to get quality prints in
> your hands ASAP.
>
> ______________________________________________________________________________
> 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.

Wendy Kelsey on tue 17 jan 06


Wedged clay that was slab rolled was how they were formed. We measured them with a ruler and cut with a fettling knife.

Suzanne Wolfe wrote: Wendy,
Can you give us some details on how the tiles were formed?
Thanks,
Suzanne Wolfe

----- Original Message -----
From: Warren Heintz
Date: Monday, January 16, 2006 5:23 pm
Subject: Re: warping tiles
To: CLAYART@LSV.CERAMICS.ORG

> Try scoring them on the bottom. Notice how commerical tiles are
> fluted.
> Wendy Kelsey wrote: Has anyone an
> idea why our tiles are warping sideways? We are using Cone 5
> Plainsman clay (with grog), placing them on gypsum wallboard bats
> and stacking them. We are keeping them uncovered otherwise in a
> cool garage. No warping up and down but they are warping somewhat
> sideways. Ideas how to stop this?
>
>
> Wendy Kelsey
> Operations Manager
> Martini Ceramics
> Custom Tile and Ceramic Arts
> 1272 Paradise Cove
> Ferndale, WA 98248-9469
> Telephone: 360-392-8607
> Fax: 832-550-4856
>
> ______________________________________________________________________________
> 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.
>
>
>
> ---------------------------------
> Yahoo! Photos
> Got holiday prints? See all the ways to get quality prints in
> your hands ASAP.
>
> ______________________________________________________________________________
> 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.

______________________________________________________________________________
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.




Wendy Kelsey
Operations Manager
Martini Ceramics
Custom Tile and Ceramic Arts
1272 Paradise Cove
Ferndale, WA 98248-9469
Telephone: 360-392-8607
Fax: 832-550-4856

Linda Blossom on tue 17 jan 06


Wendy,



Could you explain how you are making the tiles - in detail. I don't bother
with the drywall - just stack them a few high and press them gently
together. I am having a hard time figuring out what the warping is -
sideways..?? Don't score the back - it is only seen in tiles that are dry
pressed. It won't help with warping and is a waste of time. When a tile is
picked up it is stretched slightly so be sure when you move it to be dried
that you press it down flat again. I use a block of wood and then put the
next one on top and press it into the one below and keep going. Usually I
go three high. I dry them over a heater in the winter and in the sun in the
summer. Usually they dry overnight or in a few hours.



Linda

NY





Has anyone an idea why our tiles are warping sideways? We are using Cone 5
Plainsman clay (with grog), placing them on gypsum wallboard bats and
stacking them. We are keeping them uncovered otherwise in a cool garage.
No warping up and down but they are warping somewhat sideways. Ideas how to
stop this?





Wendy Kelsey

Ron Roy on thu 19 jan 06


Any clay that is unevenly stretched or compress - both situations exist in
certain kinds of slabs - particularly those that are rolled out - will
shrink at different rates when drying and during firing.

Cut a slab up into 4" squares and let the squares dry and you will see how
the tiles warp.


>Wedged clay that was slab rolled was how they were formed. We measured
>them with a ruler and cut with a fettling knife.

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513