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cracking clay

updated sun 31 aug 97

 

John Baymore on wed 30 jul 97

------------------
......cut......

I called Laguna for advice and also talked to them at NCECA about the
problem. They're at a loss and don't have any other ideas for me (so it
must be MY fault, not the clay's, right??).

......snip.....

I had been (happily) using some stock Miller 900 clay for a number of
years. Very consistent product. Then Laguna bought Miller. Since that
transition, I have had nothing but trouble with cracking in attachments
(handles, coil and throw pieces, attached feet, anything added onto a
thrown form). Different batches....same problems. Asking around I have
been told by others of experiencing similar problems. Is this a
coincidence?

I have changed clay suppliers.

Best,

................john

John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA

603-654-2752
JBaymore=40Compuserve.com

Linda Gonzalez on thu 31 jul 97

I have used B-Mix by Laguna several times; my son uses it often. It
cracks at joinings. It has to be trimmed and put together while still
very wet, then dried slowly. I usually wrap my pieces in plastic and
let time (long, long time) take care of them. Sometimes they still
crack.

lsg

Emily Muench on thu 31 jul 97

I'm also having fine cracks in the bottoms of my mugs and bowls, using Miller
#900 brown and their white stoneware!!!!! It has been so discouraging that
I've stopped working for awhile. I live in the hot, humid tropics of SW Fl,
so the drying process is very slow even if the pieces are uncovered. I think
we need to complain loud and clear, and perhaps whoever makes the clay sold
as Miller will correct the problem.

Larry Tague on thu 31 jul 97

John: I have heard from more than one potter in the Central Florida area that
the Highwater Trina Buff has a great resemblance to the Miller 900 in both
oxidation and reduction. I haven't heard about any cracking problems with
this clay, and I have converted many Miller 900 users over to the Highwater
Trina Buff. Hope this helps! Carol @"The HedgeShopper" 1-800-211-7713
----------
From: Ceramic Arts Discussion List on behalf of John Baymore
Sent: Wednesday, July 30, 1997 9:03 AM
To: Multiple recipients of list CLAYART
Subject: Cracking clay

----------------------------Original message----------------------------
------------------
......cut......

I called Laguna for advice and also talked to them at NCECA about the
problem. They're at a loss and don't have any other ideas for me (so it
must be MY fault, not the clay's, right??).

......snip.....

I had been (happily) using some stock Miller 900 clay for a number of
years. Very consistent product. Then Laguna bought Miller. Since that
transition, I have had nothing but trouble with cracking in attachments
(handles, coil and throw pieces, attached feet, anything added onto a
thrown form). Different batches....same problems. Asking around I have
been told by others of experiencing similar problems. Is this a
coincidence?

I have changed clay suppliers.

Best,

................john

John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA

603-654-2752
JBaymore=40Compuserve.com

Peggy Heer on thu 31 jul 97

Hi John and others with the cracking of attachment problem...and here I
thought it was me again...
I have been making casseroles and attaching handle which are cracking off
faster than I can put them on. I use the Laguna B-Mix as well.
I had made some mugs a month or so ago and the weather was so damp and
humid and I did not have any handles crack with them. When I made the cass.
it was warm/hot and dry and I got cracking handles. Think it is the
weather? I have an draft/air tight, moist damp cupboard and even in there
the handles cracked off. I have spent so much time re- attaching those
blessed handles I am thinking of just throwing the whole lot out except for
the # made. All were waxed after they were attached and still cracked.
I guess I will just make anything that requires handles in the rainy
season. ;>}}} That way I won't have to make tooooo many of those MUGS.
;>}}}
Of course another method I might suggest is to throw the lid with the
handle in one piece. The ones I did this way are of course fine.
I too will make handled work from good old PLAINSMAN clay in the future
rather than the Laguna. Is LAGUNA on line and LISTENING??????
As Always in Clay Peggy
------------------------------------
I have had nothing but trouble with cracking in attachments
>(handles, coil and throw pieces, attached feet, anything added onto a
>thrown form). Different batches....same problems. Asking around I have
>been told by others of experiencing similar problems. Is this a
>coincidence?
>

Peggy Heer / Heer Pottery E-Mail p4337@connect.ab.ca
52120 Range Road 223
Sherwood Park, AB. Canada T8C 1A7
Phone (403) 922-6270
http://www.ffa.ucalgary.ca/artists/pheer/

Bill Amsterlaw on fri 1 aug 97

Hi Clayart:

I use Laguna's "Miller 900" and am happy with it. I see no increased tendency
in the clay to develop S-cracks or joint separations since Laguna bought out
Miller. I get one S-crack every 30 (or so) items thrown off the hump. If I
don't throw off the hump, I get no S-cracks. My handles do not separate.


- Bill Amsterlaw (wamster@msn.com)
Plattsburgh, NY


John Baymore wrote:
>> I had been (happily) using some stock Miller 900 clay for a number of
years.... Then Laguna bought Miller. Since that
transition, I have had nothing but trouble with cracking in attachments.... I
have changed clay suppliers.
<<

Emily Muench wrote:
>> I'm also having fine cracks in the bottoms of my mugs and bowls, using
Miller #900 brown and their white stoneware!!!!! It has been so discouraging
that I've stopped working for awhile. I live in the hot, humid tropics of SW
Fl, so the drying process is very slow even if the pieces are uncovered. I
think we need to complain loud and clear, and perhaps whoever makes the clay
sold as Miller will correct the problem.
<<

Tony Hansen on sat 2 aug 97

My experience is that any clay body can be used flawlessly if you
adjust your methods to work with it.

I had an interesting experience last week that demonstrates.
Cracks appeared around the joins on all 8 handles of a set of mugs
I made. On some the handle had fallen right off.
I had done them as always, dried the mugs upside down,
handles to the centre under a cloth.

I noticed however that the break on those that fell off was not on
the join but a piece of the mug body had come out with the handle.
This clay is
silty and splits if you leave water on the surface. I had pressed
the handle on and the slip had been forced out all around the join.
I left this slip and it began a split that propagated right into
the clay. When I made another set and sponged away the slip
after pressing the handles on the problem was gone!


--
T o n y H a n s e n, I M C thansen@digitalfire.com
=========================================================
INSIGHT5/Magic of Fire II demos at http://digitalfire.com

Lori and Rob on sun 3 aug 97

I have been using Laguna's B-mix (cone 5) for several years now without
problems. I do all hand building, mostly slab. I do join while still
fairly wet and always use slip in my joints. I have not had any
problems. Sorry I can not be of more help.

Lori