WJ Seidl on thu 16 nov 06
the atmosphere? AARRGGHH!
Nancy:
First, please understand that what I'm about to say is not directed at you
personally. This applies to a lot of us, myself included. We're all guilty.
You wrote: "Is it the Laguna 66 clay".
What we all have to remember is that while a particular clay body may indeed
be defective, most of the time that is usually not the case.
It is the _reaction_ between the clay body and whatever
glaze/underglaze/slip etc. you are putting _on_ the clay body.
Blaming a clay body because of a glaze defect is like blaming a Pontiac
because the paint is peeling. (Ok bad analogy, but you get the idea.)
This is a small distinction, perhaps, but an important one to remember.
If one is having any of the multitude of glaze defects possible with a
particular clay body and glaze combination, then it is time to _alter_ one
or the other until they "play well together". Once they do, it will be good
to go for a long time, (or until the manufacturer alters the clay body
again) and you can sleep at night. Even potters who mix their own clay
bodies run into this, as materials change from one batch to the next.
And of course, to add to our misery/excitement, it can also be a firing
issue.
Best,
Wayne Seidl
still sleep deprived
-----Original Message-----
Subject: Re: Floating Blue problems....grrrrrrrrr
I took my floating blue bad mugs with me today to my supplier who has
been a tremendous help to me when I've asked questions. He took a good
look at it and thinks my problem may be underfiring of FB. Then I
realized that my FB on my top shelf on Miller 50 did NOT pinhole. Same
kiln but top shelf is a true cone 6. Different clay body....I use
Laguna's 66 and miller 50. The 66 pinholed and then I noticed a few
small pinholes on my other 66 pieces. Now I'm wondering...is it the
Laguna 66 clay. A fellow potter is sending me some samples of her
different cone 6's so I can test my FB on it and see if the problem is
the clay. I picked up the chemicals RR posted in his revised version of
FB and am going to try that on the 66 since it's my main clay in the studio.
If a piece is overfired....the blisters are larger and underfired they
are like pinholes but not truly pinholes, they are little bubbles that
burst when you rub them. Those are the type I have. I'm now going to
try and refire them at the higher temp and see if it fixes theproblem.
Any input?
Nancy
www.hilltoppottery.com
Nancy on thu 16 nov 06
the atmosphere? AARRGGHH!
Hi Wayne
I had received an email from another potter who uses a lot of Laguna's
66 and had the same issues with other glazes so I was thinking....could
it be the clay. Yes some of my other glazes also pinhole on the 66 and
yes some of them don't. I'm leaning toward the 66 has higher impurities
that need to burn out in order for the glazes to work. But again, you
are right...the glaze doesn't fit the clay so it's not the clay's fault
....:)
I think once you think you've got the answer and fix it, it may not be
the problem after all and you're searching again for the cause of
problems but it's all a part of what we do, we pot, we test, we make
happy mistakes and sad miseries as well.
I'm finding test test test and then test more and more is the way to go.
Nancy
www.hilltoppottery.com
WJ Seidl wrote:
> Nancy:
> First, please understand that what I'm about to say is not directed at you
> personally. This applies to a lot of us, myself included. We're all guilty.
> You wrote: "Is it the Laguna 66 clay".
>
> What we all have to remember is that while a particular clay body may indeed
> be defective, most of the time that is usually not the case.
> It is the _reaction_ between the clay body and whatever
> glaze/underglaze/slip etc. you are putting _on_ the clay body.
> Blaming a clay body because of a glaze defect is like blaming a Pontiac
> because the paint is peeling. (Ok bad analogy, but you get the idea.)
>
> This is a small distinction, perhaps, but an important one to remember.
> If one is having any of the multitude of glaze defects possible with a
> particular clay body and glaze combination, then it is time to _alter_ one
> or the other until they "play well together". Once they do, it will be good
> to go for a long time, (or until the manufacturer alters the clay body
> again) and you can sleep at night. Even potters who mix their own clay
> bodies run into this, as materials change from one batch to the next.
> And of course, to add to our misery/excitement, it can also be a firing
> issue.
> Best,
> Wayne Seidl
> still sleep deprived
>
> -----Original Message-----
>
> Subject: Re: Floating Blue problems....grrrrrrrrr
>
> I took my floating blue bad mugs with me today to my supplier who has
> been a tremendous help to me when I've asked questions. He took a good
> look at it and thinks my problem may be underfiring of FB. Then I
> realized that my FB on my top shelf on Miller 50 did NOT pinhole. Same
> kiln but top shelf is a true cone 6. Different clay body....I use
> Laguna's 66 and miller 50. The 66 pinholed and then I noticed a few
> small pinholes on my other 66 pieces. Now I'm wondering...is it the
> Laguna 66 clay. A fellow potter is sending me some samples of her
> different cone 6's so I can test my FB on it and see if the problem is
> the clay. I picked up the chemicals RR posted in his revised version of
> FB and am going to try that on the 66 since it's my main clay in the studio.
>
> If a piece is overfired....the blisters are larger and underfired they
> are like pinholes but not truly pinholes, they are little bubbles that
> burst when you rub them. Those are the type I have. I'm now going to
> try and refire them at the higher temp and see if it fixes theproblem.
> Any input?
>
> Nancy
> www.hilltoppottery.com
>
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