Steven D. Lee on mon 7 oct 02
I am having some trouble that my thinner pieces, pieces with walls
that are less than 3mm thick, are either buckling or warping after
trying to dip the pieces in glaze for single firing. These pieces
are not bisqued!
I am using epsom salts to try to floc the glazes and I am trying to
dunk fairly quickly and set them to dry on drywall boards almost
immediately. I am using fairly thinned out glazes as well. Perhaps
twice as thin as the fingernail test of glaze thickness.
Has anyone some advice who is experienced in single firing and
glazing?
*********************
Steven D. Lee
SD Pottery - The Little Texas Potter
http://www.sdpottery.com
millenial_age@yahoo.com
*********************
Dannon Rhudy on wed 9 oct 02
> I am having some trouble that my thinner pieces, pieces with walls
> that are less than 3mm thick, are either buckling or warping after
> trying to dip the pieces in glaze for single firing. .....
The easiest and best solution is to SPRAY your glazes on. There
are several options available for doing this, at varying prices for
the equipment. The least expensive (if you just want to try spraying)
is to get a pump sprayer from the garden department of Walmart
or Home Depot or any place that handles them. They are cheap,
come in a lot of sizes, and they work very well if you do not need
fine detail. Be sure to keep the line clean, rinse with water when
you're done glazing.
regards
Dannon Rhudy
Tony Ferguson on wed 9 oct 02
Steve,
Sounds like your claybody. Send me your recipe and I will make my
suggestions. When are you glazing: leather or bone dry? Try glazing
leather.
Thank you.
Tony Ferguson
On Lake Superior, where the sky meets the Lake
Stoneware, Porcelain, Raku
www.aquariusartgallery.com
218-727-6339
315 N. Lake Ave
Apt 312
Duluth, MN 55806
----- Original Message -----
From: "Steven D. Lee"
To:
Sent: Monday, October 07, 2002 5:24 AM
Subject: Single Firing (raw firing) and dipping glazes
> I am having some trouble that my thinner pieces, pieces with walls
> that are less than 3mm thick, are either buckling or warping after
> trying to dip the pieces in glaze for single firing. These pieces
> are not bisqued!
>
> I am using epsom salts to try to floc the glazes and I am trying to
> dunk fairly quickly and set them to dry on drywall boards almost
> immediately. I am using fairly thinned out glazes as well. Perhaps
> twice as thin as the fingernail test of glaze thickness.
>
> Has anyone some advice who is experienced in single firing and
> glazing?
>
> *********************
> Steven D. Lee
> SD Pottery - The Little Texas Potter
> http://www.sdpottery.com
> millenial_age@yahoo.com
> *********************
>
>
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>
Craig Edwards on thu 10 oct 02
Hello Steve:
It sounds like you are saturating the pots with water. What will look dry
will actually have alot of water lurking under that sufface. I have had
success warming the pots on our studio heater, before dipping --it works in
my situation.
Hope this helps
Craig Edwards
New London MN
>I am having some trouble that my thinner pieces, pieces with walls
>that are less than 3mm thick, are either buckling or warping after
>trying to dip the pieces in glaze for single firing. These pieces
>are not bisqued!
>
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Andrew Gardner on thu 17 oct 02
Steve-
I learned the hard way that greenware should not be bone dry when glazing,
but hard leather hard. This prevents water reabsorbing which causes either
your problem or cracking in firing.
Andy
Craig Martell on thu 17 oct 02
Andy sez:
>I learned the hard way that greenware should not be bone dry when glazing,
>but hard leather hard. This prevents water reabsorbing which causes either
>your problem or cracking in firing.
Hello Andy:
Failure of raw glazed ware isn't always directly related to the state of
dryness, although this can be a factor.
I used to raw glaze a lot of work for the salt kiln and I always glazed
bone dry. One of the first things I was taught about raw glazing was not
to make the work too thin. It's not critical that the cross section of the
pots be totally even but it is critical that the work isn't too thin. The
water has to go somewhere and the clay will draw off a good deal of
water. I usually lined the ware before applying glaze to the outside. To
even the strain of absorbtion, I would pour out the liner and immediately
mist the outside of the pot so it would absorb some water along with the
inner wall. I would let the pots dry somewhat before applying the outer
glazes. I would pour, dip, and spray the outsides of the pots. My failure
rate wasn't too bad using this method.
The characteristics of your claybody will have a significance with
absorbtion too. More open clays with grog and large paricle size clays
take on water very quickly and it can also carry glaze deep into the
body. These sorts of clays can be very difficult to green glaze and I
would venture to say that this sort of body is best raw glazed in the
leather hard state when there is still water involved in the clay
lattice. But, leather hard glazes need to be adjusted for shrinkage to
prevent shelling as they dry with the ware. Too little shrinkage of a
leather hard glaze and it winds up on the floor instead to staying on your
pot. The pots that I raw glazed were mostly porcelain which glazes very
nicely in the bone dry state. One thing I liked about glazing bone dry was
that more glazes that were usually applied to bisque could be used. Since
the bone dry pots were pretty much through with the plastic shrinkage,
glazes with as little as 10% clay and a little macaloid or bentonite would
work well.
I stopped raw glazing because I decorate green ware very heavily with slips
and trailing and it doesn't handle very well for raw glaze work. It's
always something!!
regards, Craig Martell Hopewell, Oregon
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