Cindy Strnad on tue 25 jul 00
Diane,
Have her place the vase on a pretty doily or napkin. You can't change the
laws of nature, and those vases are going to sweat when conditions require
them to sweat. They'll be less likely to do so if the water within is the
same temperature as the air without.
If the vases are seeping, that's another matter entirely. They absolutely
should not seep water. Oil maybe, but if they're seeping water, and if
they're glazed (not raku or some other low-fire specialty process), they're
badly made. Again, she could place them on something absorbent or on a
saucer, or just use them for dried flowers, or return them for a refund.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
earthenv@gwtc.net
www.earthenvesselssd.com
John Palmquist on tue 25 jul 00
Hi,
I have a friend that asked me why do some of the vases she has =
purchased from various clay artists seem to "sweat" and cause moisture =
on the bottom of the piece? These are pieces that are glazed on the =
inside and unglazed on the bottom. My answer to her was that either they =
are not vitrified or that this is a normal sweating that occurs in the =
more hot and humid weather(such as toilet bowls).Does anyone have any =
more imput? Also what is there that we can do to avoid this?
Thanks,
Diane
Dave Finkelnburg on tue 25 jul 00
Diane,
You are right on both counts!
If the problem is condensation, a frequent issue in humid areas, the
best solution is a footed vessel, or as an alternative, three glued-on
buttons of felt or cork or some other material which gets the vase up off
the surface so air can move underneath and keep the bottom relatively dry.
Air movement is the key.
As to vitrification, I was helped a lot by this list a couple years ago
when I had a problem with undervitrified vases seeping water through the
base very slowly. Once I started checking for how much moisture the fired
clay absorbed, and got the firing right (one cone higher), the problem
disappeared. Education, testing, and customers who return such defective
vases are the only real solutions I see.
Good potting!
Dave Finkelnburg in sunny southern Idaho
-----Original Message-----
I have a friend that asked me why do some of the vases she has purchased
from various clay artists seem to "sweat" and cause moisture on the bottom
of the piece? These are pieces that are glazed on the inside and unglazed on
the bottom. My answer to her was that either they are not vitrified or that
this is a normal sweating that occurs in the more hot and humid weather(such
as toilet bowls).Does anyone have any more imput? Also what is there that we
can do to avoid this?
Thanks,
Diane
Loraxwoods@AOL.COM on tue 25 jul 00
Diane,
In Miami we tend to have that hot and humid weather that encourages a lot
of sweating both on pots and people. I pour Thompson's Water Seal into my
vases, swirl it around and then pour it out and also brush a coat on the
bottom of the vase. It helps.
Rainy and humid in Miami,
Nora
The Brinks on tue 25 jul 00
Hi Diane,
Here are several things I've done:
1. Leave enough clay at the bottom when you are throwing to be able to have
a good footring, and then cut away all but whatever number of legs you like.
Any sweating should evaporate.
2. Throw a separate stand or base for each vase--using bowl with footring
shape, cut away a lot of the bowl to leave legs. Can be plain or fancy,
with cutouts if it suits the piece. If, like me, you find you have made a
base that overwhelms the vase, then you can make an important looking lid
for it, perhaps add handles or other stuff and you have made a "Ritual
Vessel"!
(:-)
3. Throw a separate disc for a base, or make a square slab one. A dark
green glaze is nice for this, since most arrangements will have some green
leaves. Or just stained and unglazed, for a more earthy look. Whatever
you like. People like getting an extra little piece "thrown in".
I am firing a cone 6-10 clay to cone 7 or so. I would hope at cone 10 there
should be full vitrification and no "sweating".
There should be quite a bit of info in the archives about various sealants,
but I have never used any of them.
All the best,
Ann Brink in CA
----- Original Message -----
From: John Palmquist
To:
Sent: Tuesday, July 25, 2000 7:05 AM
Subject: Water seepage in vases
Hi,
I have a friend that asked me why do some of the vases she has purchased
from various clay artists seem to "sweat" and cause moisture on the bottom
of the piece? These are pieces that are glazed on the inside and unglazed on
the bottom. My answer to her was that either they are not vitrified or that
this is a normal sweating that occurs in the more hot and humid weather(such
as toilet bowls).Does anyone have any more imput? Also what is there that we
can do to avoid this?
Thanks,
Diane
____________________________________________________________________________
__
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.
Eydie DeVincenzi on thu 27 jul 00
I just stumbled on a idea for preventing moisture from seeping from the
bottom of a vase: =
design the ceramic vase to allow a glass jar or container to fit inside. =
The water and flowers go into the jar which then slips into and is hidden=
by the beautiful vase.
Would that work for you?
Eydie =
John Baymore on thu 27 jul 00
........... why do some of the vases she has purchased from various clay
artists seem to "sweat" and cause moisture on the bottom of the piece?
................... My answer to her was that either they are not vitrifi=
ed
or that this is a normal sweating that occurs in the more hot and humid
weather(such as toilet bowls).Does anyone have any more imput? Also what =
is
there that we can do to avoid this?
Diane,
Good answers! You about covered it. =
This issue is tied in with the discussion of long firing range claybodies=
in another thread. If a body is rated for use over a spread of cone
6-10...... my guess is it is a good bet that at cone 6 the clay is not ve=
ry
vitrified....... or at cone 10 it is pretty well overfired . Either o=
ne
will give you technical problems. It really probably is a cone 7-8 body
trying to be "everythng to everybody". A formula for failure .
So the reason that some pots do seep / weep/ leak is really that it is a
technical defect in the product that hasn't been caught by the potter. W=
e
all miss an occasional piece here and there for technical defects.... but=
if this is a regular occurance for a potter....then they have not done
their "technical homework" very well. =
Apparent Porosity / Absorbancy is a pretty simple test to perform and is
one of the most basic tests a potter can do. Don't just trust that becau=
se
the box says cone 6 to 10 that the clay is what YOU want it to be anywher=
e
in the supposed useful range. Test it to see what properties it has at t=
he
point that you use it. You may get a surprise.
There was a long discussion about this subject of weeping/seeping long
range bodies and so on a while back. My guess is that it ended up in the=
archives somehwhere.
Best,
........................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JBaymore@compuserve.com
John.Baymore@GSD-CO.com
"Earth, Water, and Fire Noborigama Woodfiring Workshop August 18-27,
2000"
Kelley Webb Randel on thu 27 jul 00
With my love of pottery and cut flowers, I have
used plastic cups and glasses inside my vases
to cut the condensation. old tupperware, qt cups and
plastic glasses, anything that fits and is not seen!
be well,
kelley
| |
|
