Marcia Selsor on thu 2 nov 06
Paul
I use a piece of wood..modeling stick or rib while trimming. Try it
on the lip when the pot is about ready for trimming.
It is like a wet burnishing..push the grog back into the surface.
Marcia Selsor
http://marciaselsor.com
Paul Borian on thu 2 nov 06
i use a lot of grog and it's not just grog, it's super fine mullite which
is sharper than most grogs and so far nothing i have tried on the wheel can
smooth out the rims. My glazes are not applied thick enough to prevent the
grog from giving the finished pots a sharp feeling all along the rims. The
only thing that works is to sand the bisqued pots (i never sand greenware)
with drywall sanding sponges and at this point i do this to almost all the
pots, not just mugs since i always use about 15% mullite. It takes care of
the problem and, even though i can do it outside it is still pretty dusty
and gets harder to deal with in cold/rainy/snowy weather since it takes a
while.
Does anyone else have to deal with this kind of thing and, if so, have you
found a way to take care of the problem while the pots are still on the
wheel?
thanks,
Paul
Charlie Cummings on thu 2 nov 06
Hi Paul,
Have you considered putting a coat of slip on the rims? You could
use the same clay body sans grog for the slip. A couple of seconds
with a brush could save minutes of sanding.
Charlie Cummings
At 05:05 PM 11/2/2006, you wrote:
>i use a lot of grog and it's not just grog, it's super fine mullite which
>is sharper than most grogs and so far nothing i have tried on the wheel can
>smooth out the rims. My glazes are not applied thick enough to prevent the
>grog from giving the finished pots a sharp feeling all along the rims. The
>only thing that works is to sand the bisqued pots (i never sand greenware)
>with drywall sanding sponges and at this point i do this to almost all the
>pots, not just mugs since i always use about 15% mullite. It takes care of
>the problem and, even though i can do it outside it is still pretty dusty
>and gets harder to deal with in cold/rainy/snowy weather since it takes a
>while.
>Does anyone else have to deal with this kind of thing and, if so, have you
>found a way to take care of the problem while the pots are still on the
>wheel?
>thanks,
>Paul
>
>______________________________________________________________________________
>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.
Charlie Cummings Clay Studio & Gallery
4130 South Clinton Street
Fort Wayne, IN 46806
Charlie@claylink.com
260-458-9160
www.claylink.com
Bruce Girrell on thu 2 nov 06
First, I minimize the problem by burnishing the rims when they are leather
hard. I use a tumble polished stone, a wooden rib, a steel rib, just about
anything, to produce a smooth finish on the rim. I usually do the burnishing
by putting the piece back on the wheel and simply holding the burnishing
tool against the rotating pot rim, moving it as required to be sure that any
area likely to touch someone's lips will be smoothed.
During firing the clay will shrink more than the grog and some roughness
will reappear but most of the time it isn't offensive. Any bumps that do
feel unpleasant can be smoothed out with a small amount of work with
abrasives. I use a round ball diamond bit in a Dremel tool or a product from
DMT called diamond honing cones (see
http://www.woodcraft.com/family.aspx?FamilyID=232 for example). Diamond
tools aren't nearly as expensive as they sound. They do an excellent job and
they last a long time if they are not abused.
To avoid making mistakes that would cause me to grind away the wrong areas,
I work under magnification. I use a low power stereo microscope, but any
decent magnification system, like a magnifying visor, would do just as well.
Good lighting is your other friend.
Bruce Girrell
tropifauna on thu 2 nov 06
Paul,
is sharper than most grogs >
Had same problem with one of my concoctions-The paranoids at the
airport/border will have a feastday with trying to fingerprint me-solved the
sharp etches by straining a small amount of the prepared clay through a
piece of stocking "borrowed" from my significant other and brushing that
over the etches after trimming. Hope it works for you too.
Jan
pdp1@EARTHLINK.NET on thu 2 nov 06
Hi Charlie,
Have you tried useing a small bit of damp
Chamois? - while the Mug is still on the wheel,
revolving, before wireing off...to smothe the edge
of the rim and almost polish it...
Or, similarly even, or may be better, with a small
wet piece of Chamois, when you are Trimming...?
Phil
el v
> At 05:05 PM 11/2/2006, you wrote:
> >i use a lot of grog and it's not just grog,
it's super fine mullite which
> >is sharper than most grogs and so far nothing i
have tried on the wheel can
> >smooth out the rims. My glazes are not applied
thick enough to prevent the
> >grog from giving the finished pots a sharp
feeling all along the rims. The
> >only thing that works is to sand the bisqued
pots (i never sand greenware)
> >with drywall sanding sponges and at this point
i do this to almost all the
> >pots, not just mugs since i always use about
15% mullite. It takes care of
> >the problem and, even though i can do it
outside it is still pretty dusty
> >and gets harder to deal with in
cold/rainy/snowy weather since it takes a
> >while.
> >Does anyone else have to deal with this kind of
thing and, if so, have you
> >found a way to take care of the problem while
the pots are still on the
> >wheel?
> >thanks,
> >Paul
> >
>
>_________________________________________________
_____________________________
> >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.
>
>
> Charlie Cummings Clay Studio & Gallery
> 4130 South Clinton Street
> Fort Wayne, IN 46806
> Charlie@claylink.com
> 260-458-9160
> www.claylink.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.
>
Michael Wendt on thu 2 nov 06
Paul,
When the pots are waxy hard,
try a burnishing tool. We have
used spoons, rods, and even
glazed forms that have specific
shapes for the things we make.
Burnishing at the right time works
well on low clay content bodies
to fix the rough surface problem.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, Idaho 83501
USA
wendtpot@lewiston.com
www.wendtpottery.com
Paul asked:
Does anyone else have to deal with this kind of thing
and, if so, have you
found a way to take care of the problem while the pots
are still on the
wheel?
thanks,
Paul
Peter Cunicelli on fri 3 nov 06
Hey Paul,
All my work is handbuilt, so I've come across this problem quite a few
times. I found that using a piece of canvas when it's leather hard works
really well.
Peter
(www.petercunicelli.com)
Fred Parker on fri 3 nov 06
I use a small leather scrap -- the kind used for ladies' jackets -- soaked
in water. Chamois would work also. The last thing I do before cutting
the pot from the bat is gently drape the wet leather over the rim and hold
it there for a few revolutions. Don't sponge or touch afterward.
Fred Parker
On Thu, 2 Nov 2006 17:05:14 -0500, Paul Borian wrote:
>SNIP
>Does anyone else have to deal with this kind of thing and, if so, have you
>found a way to take care of the problem while the pots are still on the
>wheel?
>thanks,
>Paul
>
Chris Trabka on sat 4 nov 06
I was once shown how to make very smooth rims by a potter from Eastern
Europe. He used a piece of bicycle inner tube in place of a chamois. The
piece of inner tube I now use is about 3/4-inch wide and about 4-inches
long. I use it to make all my rims and have found that it is handy when
pots are leather hard to smooth out gouges/dings. It is like a softer more
pliable version of the sherril mud tools.
Chris
Bonnie Staffel on sat 4 nov 06
One of the earliest lessons I learned when studying clay with Harvey
Littleton at the Toledo Museum Ceramic classes, was to compress the =
clay.
So many potters use a sponge to assist in their throwing which takes =
away
the fines that make the clay body strong. So the pot appears groggy and
rough. Many use too much water and that also removes the fines. If you
keep this principle in mind when you are throwing and use your =
hands/fingers
to compress the clay your grog or sand will also be pressed to the inner
portions of the clay. I also use a damp chamois strip of leather to
compress the lip of the pot several times during the throwing process. =
This
also pushes the grog/sand into the body. Many potters also leave the =
slip
on the rim which then is weak if not removed or compressed. =20
The only time I am aware of the rougher particles in the clay is when
trimming. I then compress the trimmed part with a wooden flat stick. I
especially take care when trimming a foot to compress that area as well. =
It
sure minimizes any grinding. =20
Ever notice after sponging the water out of the bottom of your pot, that =
it
appears rough and grainy? That is when I run my fingers over the area =
to
compress it to push the grog back into the clay. =20
So many flaws that occur in claymaking can be solved by using common =
sense
and a little study of the basics and chemistry of clay. One of the =
other
early lessons I learned was from Michael Cardew's book, Pioneer Pottery.
His method of throwing a vase illustrates the system of making the form
concave in the pulling up process and then bowing out after the wall is
formed. The pot stands up amazingly from this method. One of my
apprentices was having trouble with her porcelain pots slumping after
forming. I suggested she use Cardew's method, and the problem =
disappeared.
Hope this lesson helps you solve some of your own problems.
Bonnie Staffel
After the glaze firing, I have a stone that all I have to do is give it =
a
quick rub as some of the finer particles do emerge from the shrinkage =
that
occurs from firing. =20
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD Throwing with Coils and Slabs
DVD Beginning Processes
Charter Member Potters Council
Ron Roy on sat 4 nov 06
One solution is to design your rims in such a way as to hold more glaze -
to cover the grog.
Double dipping after the first coat of glaze has dried a little will work -
and even better if there are no sharp edges where the glaze will thin out
as it melts.
RR
>i use a lot of grog and it's not just grog, it's super fine mullite which
>is sharper than most grogs and so far nothing i have tried on the wheel can
>smooth out the rims. My glazes are not applied thick enough to prevent the
>grog from giving the finished pots a sharp feeling all along the rims. The
>only thing that works is to sand the bisqued pots (i never sand greenware)
>with drywall sanding sponges and at this point i do this to almost all the
>pots, not just mugs since i always use about 15% mullite. It takes care of
>the problem and, even though i can do it outside it is still pretty dusty
>and gets harder to deal with in cold/rainy/snowy weather since it takes a
>while.
>Does anyone else have to deal with this kind of thing and, if so, have you
>found a way to take care of the problem while the pots are still on the
>wheel?
>thanks,
>Paul
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Bonita Cohn on sat 4 nov 06
after compressing the rim as marcia suggested you can
also run over the rim, with a chamois full of
slurry--this bulks it up and can even fill in areas
that are rough or have lost their "skin."
Bonita in San Francisco.....
Bonita Cohn
http://www.bonitacohn.com
____________________________________________________________________________________
Want to start your own business? Learn how on Yahoo! Small Business
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Russel Fouts on sat 4 nov 06
I use a lot of grog and it's not just grog, it's super fine mullite
which is sharper than most grogs <<
Maybe this is an obvious question but why the sharp mullite grog in clay
used for a functional piece?
Could you change the grog?
Russel
Heloisa Nunes on wed 8 nov 06
Besides chamois, a very soft (dry cleaner's ) thin ( 1/2 inch thickness more
or less) piece of plastic will work very well too!!!
All the best,
Heloisa Nunes,
Sao Paulo, Brazil
Craig Clark on wed 8 nov 06
Adding one more suggestion to many that will indeed work well: I
often use a very heavily grogged clay body.I initially use a chamy cloth
to smooth the rim of the pots as the last step in throwing the form. A
slight downward pressure with a piece drapped over the spinning rim
accomplishes the task quite well. The result is a nice smooth rim.
When trimming a heavily grogged body there is also the problem of
what I like to call pot acne. The surface is often pot marked with
numerous tiny to moderate size holes which are the result to the grog
having been torn from the clay and dragged across the surface during
trimming. What has worked well for me is to cover the affected surface
area of the pot with a thin layer of the throwing slip. You can just use
a sponge to do this. I will then first use my throwing stick, the knob
end, to gently smooth the surface, and then use a flexible rubber rib to
finish. This is done while the pot is turning at a moderate speed on the
wheel before you remove it. If is the last stage of the trimming process
for me. If, after applying and smoothing the slip the pot is a bit rough
just repeat the procedure. This also works without well with the
exclusive use of the rubber rib without the stick.
Lastly, after the pots have set up to where you are about to attach
the handles, just go ahead and give the rim a once or twice around with
a light damp chamy as I believe has been suggested. The glaze will take
care of the rest.
Hope this helps
Craig Dunn Clark
619 East 11 1/2 St
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
Heloisa Nunes wrote:
> Besides chamois, a very soft (dry cleaner's ) thin ( 1/2 inch
> thickness more
> or less) piece of plastic will work very well too!!!
> All the best,
> Heloisa Nunes,
> Sao Paulo, Brazil
>
> ______________________________________________________________________________
>
> 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.
>
Lisa E on wed 8 nov 06
Another suggestion for the rim is a thick elastic band cut in half. Hold on
each side of the rim, pressing downwards on a bit of an angle so the elastic
band doesn't grab the clay. It smooths out the rim but also compresses the
clay to reducing cracking and longevity of the rim over the years.
Lisa
On 11/8/06, Craig Clark wrote:
>
> Adding one more suggestion to many that will indeed work well: I
> often use a very heavily grogged clay body.I initially use a chamy cloth
> to smooth the rim of the pots as the last step in throwing the form. A
> slight downward pressure with a piece drapped over the spinning rim
> accomplishes the task quite well. The result is a nice smooth rim.
> When trimming a heavily grogged body there is also the problem of
> what I like to call pot acne. The surface is often pot marked with
> numerous tiny to moderate size holes which are the result to the grog
> having been torn from the clay and dragged across the surface during
> trimming. What has worked well for me is to cover the affected surface
> area of the pot with a thin layer of the throwing slip. You can just use
> a sponge to do this. I will then first use my throwing stick, the knob
> end, to gently smooth the surface, and then use a flexible rubber rib to
> finish. This is done while the pot is turning at a moderate speed on the
> wheel before you remove it. If is the last stage of the trimming process
> for me. If, after applying and smoothing the slip the pot is a bit rough
> just repeat the procedure. This also works without well with the
> exclusive use of the rubber rib without the stick.
> Lastly, after the pots have set up to where you are about to attach
> the handles, just go ahead and give the rim a once or twice around with
> a light damp chamy as I believe has been suggested. The glaze will take
> care of the rest.
> Hope this helps
> Craig Dunn Clark
> 619 East 11 1/2 St
> Houston, Texas 77008
> (713)861-2083
> mudman@hal-pc.org
>
> Heloisa Nunes wrote:
> > Besides chamois, a very soft (dry cleaner's ) thin ( 1/2 inch
> > thickness more
> > or less) piece of plastic will work very well too!!!
> > All the best,
> > Heloisa Nunes,
> > Sao Paulo, Brazil
> >
> >
> ______________________________________________________________________________
> >
> > 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.
>
--
Lisa E
Sunny Daze Design Pottery Studio
Squamish, BC
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