Wayne Seidl on tue 25 jul 06
To add to Norman's post:
I have also found that using clay directly from a pug mill requires just =
a bit of "finesse", without which s-cracks are much more likely to =
occur:
1) Determine in which direction your pug mill's auger turns, and in
which direction your wheel turns when you throw.
2) Orient your pug of clay on your wheel so that as you throw, you are
throwing the clay in the OPPOSITE direction from which it was augered =
out of
the pugmill.
For example, with the pugged clay coming from the left end of the pug =
mill
(pug mill points left); if you notice that the auger is turning
counterclockwise (when you lift the hopper door, the top of the auger is
rotating away from you) and you throw counterclockwise (left side of the =
bat
coming toward you) then you should place the pug of clay on the bat with =
the
end that first came from the pug mill DOWN on the bat. This negates
(reverses) the "spin" put on the clay from the pug mill as you center =
and
throw. Vice versa if your auger spins clockwise, or you throw =
clockwise.
Of course, you can always choose to wedge the clay before placing it on =
the
bat, but let's be real here...that's why most of us bought the darn pug =
mill
to begin with...to eliminate having to wedge.
For me, this little orientation trick (along with proper compression,
removing water, etc.) has eliminated s-cracks.
Just my 2=A2. YMMV.
Best,
Wayne Seidl
watching the road sizzle and steam after a shower...hot, hot, HOT
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Norman
Aufrichtig
Sent: Tuesday, July 25, 2006 12:54 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: cracks
hi fred,
not to discount what you said, am careful how i use the clay from the
pugmill, but if you want to test the compression argument i have a
suggestion. throw some forms off the hump but do not compress the =
bottom,
throw some more but compress the bottom use a rib to do this, they =
should
all have the same thickness bottom. don't trim the bottom, as this does
compress the bottom. i think this will show the value of compressing .
drying is somewhat important but if a piece is well thrown it can be =
dried
pretty fast. i live in the dry southwest use b mix and dry my clay very
fast, very seldom do i have a problem with cracking.
norman a
Bonnie Staffel on wed 2 aug 06
Hey, Bill. My supplier doesn't even twist the top of the bag, just lays =
it
over thinking that the pressure of the box will hold it down and keep =
the
air out. No way!!! Sometimes my boxes arrive with broken sides or =
holes
poked. I sure don't have the time or muscle to open every bag and =
retwist
the tops. My last batch, I have covered with plastic, in the hopes that =
the
AC in summer and the heat in winter in my studio, will be deterred. The
plastic on the bags used to be tied with sticky tape. At least that =
usually
stayed on the opened plastic bag, or one could take it off and =
discarded.
Oh, for the good old days!!!=20
Warm regards,
Bonnie Staffel
http://webpages.charter.net/bstaffel/
Dan and Laurel on wed 2 aug 06
We get our clay in the same open top bags but without the holes, and they
seem to work well for quit a long time. The clay is always too dry to throw
so I got into added water to the bag and waiting a few weeks. Maybe flip the
box once to twice to help even the water out. Perfect soft clay is the
result. I also pug it to be sure it is well mixed and in a form I can use
but in looking at it when we cut it up to feed the beast it look very
uniform. I alway have four or so boxes working at a time and this it the
easyest way to fix hard clay we have found yet.
Working with some year old reclaim this week, been in a big bucket of water
ageing to a nice blue/gray. a bit of a smell but what a joy to throw.
Dan & Laurel
| |
|
