Paul Herman on mon 26 sep 05
Hello Frank,
I will try to give you some answers below, amid.
On Sep 26, 2005, at 4:53 PM, Frank Jankovsky wrote:
> Some of our latest products look like Dali clocks, dripping off
> shelves, melted in pools on shelves etc....
Sounds like you got 'low fire' clay in a high fire kiln.
>
> I am very intimidated and nervous coming here to query this forum,
> but it is
> either get help here or give it up.
Not necessarily, there are a lot of good books out there.
>
> I have absolutely no backround in ceramics so please go easy on me.
OK
>
> My list of questions is long but I will start with the following:
>
> If you have reduced your body from around 016 to 010, when should
> you begin
> reducing for a ^10 firing?
>
> Exactly what is the theory on this reduction business, is the
> environment
> merely moving electrons around or is it actually stealing "oxygen"
> atoms
> from the molten mix?
It's stealing, but works best on the unmelted mix. The flame is
hungry for oxygen and will take it from the ware. In order to take
the oxygen, porous ware helps.
>
> So can the alchemy happen at any time during the firing or does it
> need to
> happen as the glaze is melting? In other words, can I put the kiln
> into
> reduction at ^10, or does reduction need to begin when the glaze is
> sintering and just beginig to melt. Can the reduction environment
> "reach
> thru' the molten glaze to do it's magic or must it be present
> before it
> becomes a thick fluid??
I try to start reduction around cones 012-010 before the glaze
sinters. The reduction will not get through a melted glaze. That's an
important point.
>
> This is the first of many questions I have so I hope you are all
> bored and
> just dying to help!
>
> Thanks,
>
> Frank
>
No sweat,
Paul Herman
Great Basin Pottery
Doyle, California US
greatbasinpottery.com
Charles Moore on mon 26 sep 05
Frank,
Please immediately get John Britt's "The Complete Guide to High-Fire
Glazes." Britt gives a great deal of information on firing and glazing. It
is an excellent book, beautifully put together with many fine recipes and
illustrations.
Charles Moore
Sacramento
----- Original Message -----
From: "Frank Jankovsky"
To:
Sent: Monday, September 26, 2005 4:53 PM
Subject: Neophyte has questions on reduction firing
> Exactly what is the theory on this reduction business, is the environment
> merely moving electrons around or is it actually stealing "oxygen" atoms
> from the molten mix?
>
> So can the alchemy happen at any time during the firing or does it need to
> happen as the glaze is melting? In other words, can I put the kiln into
> reduction at ^10, or does reduction need to begin when the glaze is
> sintering and just beginig to melt. Can the reduction environment "reach
> thru' the molten glaze to do it's magic or must it be present before it
> becomes a thick fluid??
>
> Frank
>
Frank Jankovsky on mon 26 sep 05
I am my wife's kiln slave. She is the artist and I am the Pyro. We have
graduated from electric firing to gas firing. We are now producing more
skeet (that's all these things are good for) than you can shoot a shotgun
at. Some of our latest products look like Dali clocks, dripping off
shelves, melted in pools on shelves etc....
I am very intimidated and nervous coming here to query this forum, but it is
either get help here or give it up.
I have absolutely no backround in ceramics so please go easy on me.
My list of questions is long but I will start with the following:
If you have reduced your body from around 016 to 010, when should you begin
reducing for a ^10 firing?
Exactly what is the theory on this reduction business, is the environment
merely moving electrons around or is it actually stealing "oxygen" atoms
from the molten mix?
So can the alchemy happen at any time during the firing or does it need to
happen as the glaze is melting? In other words, can I put the kiln into
reduction at ^10, or does reduction need to begin when the glaze is
sintering and just beginig to melt. Can the reduction environment "reach
thru' the molten glaze to do it's magic or must it be present before it
becomes a thick fluid??
This is the first of many questions I have so I hope you are all bored and
just dying to help!
Thanks,
Frank
Marcia Selsor on tue 27 sep 05
Don't feel intimidated by this group. You'll probably get more
answers than you can comprehend.
I fired ^6 reduction for 20+ years doing the body reduction before
the clay surface starts to seal my choice being between ^010 -^04
for about 45 minutes. Then when hitting my desired glaze cones and
evenly up the kiln, started to reduce again for about 45 minutes to
an hour.
No oxy probe. I don't know how to use one. I am sure you will get
more specific instruction from more technically advanced than I.
I used the method of holding a stick in the peephole. If it doesn't
burn while the greenish flame is licking out of the kiln, you're in
reduction. You don't need belching black smoke exuding from every
crevice . IMHO
Good luck. Compare all the answers you'll receive and see what works
for you. Every situation is different.
Question: why are the pieces melting in your kiln. My assumption
would be you got too hot for the clay body. You need to give more
details to get the problems solved.
Marcia Selsor
On Sep 26, 2005, at 5:53 PM, Frank Jankovsky wrote:
> I am my wife's kiln slave. She is the artist and I am the Pyro.
> We have
> graduated from electric firing to gas firing. We are now producing
> more
> skeet (that's all these things are good for) than you can shoot a
> shotgun
> at. Some of our latest products look like Dali clocks, dripping off
> shelves, melted in pools on shelves etc....
>
> I am very intimidated and nervous coming here to query this forum,
> but it is
> either get help here or give it up.
>
> I have absolutely no backround in ceramics so please go easy on me.
>
> My list of questions is long but I will start with the following:
>
> If you have reduced your body from around 016 to 010, when should
> you begin
> reducing for a ^10 firing?
>
> Exactly what is the theory on this reduction business, is the
> environment
> merely moving electrons around or is it actually stealing "oxygen"
> atoms
> from the molten mix?
>
> So can the alchemy happen at any time during the firing or does it
> need to
> happen as the glaze is melting? In other words, can I put the kiln
> into
> reduction at ^10, or does reduction need to begin when the glaze is
> sintering and just beginig to melt. Can the reduction environment
> "reach
> thru' the molten glaze to do it's magic or must it be present
> before it
> becomes a thick fluid??
>
> This is the first of many questions I have so I hope you are all
> bored and
> just dying to help!
>
> Thanks,
>
> Frank
>
> ______
>
William & Susan Schran User on tue 27 sep 05
On 9/26/05 7:53 PM, "Frank Jankovsky" wrote:
> Some of our latest products look like Dali clocks, dripping off
> shelves, melted in pools on shelves etc....
Frank - Your first issue is using a clay that can be fired to ^10, if that
is the temperature you will be firing to - forget everything else until that
happens.
--
William "Bill" Schran
Fredericksburg, Virginia
Steve Slatin on tue 27 sep 05
Marcia --
Golly, what a killjoy.
--- Marcia Selsor wrote:
> You don't need belching black smoke
> exuding from every
> crevice .
Steve Slatin --
Drove downtown in the rain
9:30 on a Tuesday night
Just to check out the
Late night record shop
__________________________________________________
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Marcia Selsor on wed 28 sep 05
And there is a distinct smell of reduction. Kind of gaggy smell. Look
for green purpled flames.
Marcia
On Sep 28, 2005, at 3:42 PM, Frank J. wrote:
> Thanks Marcia,
>
> Our kiln does not ever belch black smoke, I guess we don't have enough
> gas pressure for that. You comment about putting a stick into the
> peep
> and seeing if it burns is great since I can't really tell if we are in
> reduction or not. I think we are but many of the books say you can
> have
> black smoke coming out and still not be in reduction. Very confusing
> but I think the fact that we are getting some red out of a glaze that
> contains CaCo3 when overlapped with a Spodumene glaze means we are in
> reduction? And that of course leads to a whole new topic about the
> colors that are coming out of the kiln, which I am saving for my next
> round of questions.
Frank J. on wed 28 sep 05
Paul, thank you for your reply.
We picked up a used pugmill last winter and Jeri has been recycling all
the old dried out bags around the studio and I guess some low fire clay
got mixed in. The lowfire clay is distributed in varying quantities
thru out many of the pots, but that is a simple issue to avoid in the
future.
I would like a little clarification regarding the reduction comments you
made below. In one case you are talking about the flame being hungry
for oxygen and it taking it from the ware. I assume you are speaking of
"body reduction" at this point. I understand that that needs to happen
before the glaze begins to liquefy, but why is it done other than to
change the color of the underlaying clay body? In your second comment
you seem to be talking about body reduction again, yes?
I am still not clear about the reduction with the glaze and when this
should be happening. Can you do body reduction, go back to an oxidizing
atmosphere and then return to reduction at say ^9 for a ^10 firing, or
does the kiln need to be in reduction during the entire process of glass
formation?
Thanks,
Frank
Paul Herman wrote:
> Hello Frank,
>
> I will try to give you some answers below, amid.
>
> On Sep 26, 2005, at 4:53 PM, Frank Jankovsky wrote:
>
>> Some of our latest products look like Dali clocks, dripping off
>> shelves, melted in pools on shelves etc....
>
>
> Sounds like you got 'low fire' clay in a high fire kiln.
>
>>
>> I am very intimidated and nervous coming here to query this forum,
>> but it is
>> either get help here or give it up.
>
>
> Not necessarily, there are a lot of good books out there.
>
>>
>> I have absolutely no backround in ceramics so please go easy on me.
>
>
> OK
>
>>
>> My list of questions is long but I will start with the following:
>>
>> If you have reduced your body from around 016 to 010, when should
>> you begin
>> reducing for a ^10 firing?
>>
>> Exactly what is the theory on this reduction business, is the
>> environment
>> merely moving electrons around or is it actually stealing "oxygen"
>> atoms
>> from the molten mix?
>
>
> It's stealing, but works best on the unmelted mix. The flame is
> hungry for oxygen and will take it from the ware. In order to take
> the oxygen, porous ware helps.
>
>>
>> So can the alchemy happen at any time during the firing or does it
>> need to
>> happen as the glaze is melting? In other words, can I put the kiln
>> into
>> reduction at ^10, or does reduction need to begin when the glaze is
>> sintering and just beginig to melt. Can the reduction environment
>> "reach
>> thru' the molten glaze to do it's magic or must it be present
>> before it
>> becomes a thick fluid??
>
>
> I try to start reduction around cones 012-010 before the glaze
> sinters. The reduction will not get through a melted glaze. That's an
> important point.
>
>>
>> This is the first of many questions I have so I hope you are all
>> bored and
>> just dying to help!
>>
>> Thanks,
>>
>> Frank
>>
>
> No sweat,
>
> Paul Herman
> Great Basin Pottery
> Doyle, California US
> greatbasinpottery.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.
>
Frank J. on wed 28 sep 05
Thanks Marcia,
Our kiln does not ever belch black smoke, I guess we don't have enough
gas pressure for that. You comment about putting a stick into the peep
and seeing if it burns is great since I can't really tell if we are in
reduction or not. I think we are but many of the books say you can have
black smoke coming out and still not be in reduction. Very confusing
but I think the fact that we are getting some red out of a glaze that
contains CaCo3 when overlapped with a Spodumene glaze means we are in
reduction? And that of course leads to a whole new topic about the
colors that are coming out of the kiln, which I am saving for my next
round of questions.
Marcia Selsor wrote:
> Don't feel intimidated by this group. You'll probably get more
> answers than you can comprehend.
> I fired ^6 reduction for 20+ years doing the body reduction before
> the clay surface starts to seal my choice being between ^010 -^04
> for about 45 minutes. Then when hitting my desired glaze cones and
> evenly up the kiln, started to reduce again for about 45 minutes to
> an hour.
> No oxy probe. I don't know how to use one. I am sure you will get
> more specific instruction from more technically advanced than I.
> I used the method of holding a stick in the peephole. If it doesn't
> burn while the greenish flame is licking out of the kiln, you're in
> reduction. You don't need belching black smoke exuding from every
> crevice . IMHO
> Good luck. Compare all the answers you'll receive and see what works
> for you. Every situation is different.
> Question: why are the pieces melting in your kiln. My assumption
> would be you got too hot for the clay body. You need to give more
> details to get the problems solved.
> Marcia Selsor
>
> On Sep 26, 2005, at 5:53 PM, Frank Jankovsky wrote:
>
>> I am my wife's kiln slave. She is the artist and I am the Pyro.
>> We have
>> graduated from electric firing to gas firing. We are now producing
>> more
>> skeet (that's all these things are good for) than you can shoot a
>> shotgun
>> at. Some of our latest products look like Dali clocks, dripping off
>> shelves, melted in pools on shelves etc....
>>
>> I am very intimidated and nervous coming here to query this forum,
>> but it is
>> either get help here or give it up.
>>
>> I have absolutely no backround in ceramics so please go easy on me.
>>
>> My list of questions is long but I will start with the following:
>>
>> If you have reduced your body from around 016 to 010, when should
>> you begin
>> reducing for a ^10 firing?
>>
>> Exactly what is the theory on this reduction business, is the
>> environment
>> merely moving electrons around or is it actually stealing "oxygen"
>> atoms
>> from the molten mix?
>>
>> So can the alchemy happen at any time during the firing or does it
>> need to
>> happen as the glaze is melting? In other words, can I put the kiln
>> into
>> reduction at ^10, or does reduction need to begin when the glaze is
>> sintering and just beginig to melt. Can the reduction environment
>> "reach
>> thru' the molten glaze to do it's magic or must it be present
>> before it
>> becomes a thick fluid??
>>
>> This is the first of many questions I have so I hope you are all
>> bored and
>> just dying to help!
>>
>> Thanks,
>>
>> Frank
>>
>> ______
>>
>
> ______________________________________________________________________________
>
> 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.
>
Paul Herman on thu 29 sep 05
Hi Frank,
I don't differentiate between body and glaze reduction. In order to
get a properly reduced body, I try to reduce before the clay
vitrifies. Same with the glaze. Reduce before the glaze starts to
melt, and seals itself off. The flame is stealing oxygen from the
glazes too, which will for example turn your copper red.
After the initial rather heavy reduction at 1600F-1850F, I continue a
light reduction until the end of the firing. I'm not sure if some
periods of oxidation would cause trouble, but do what seems to work.
Best wishes,
Paul Herman
Great Basin Pottery
Doyle, California US
greatbasinpottery.com
On Sep 28, 2005, at 2:32 PM, Frank J. wrote:
> Paul, thank you for your reply.
>
> We picked up a used pugmill last winter and Jeri has been recycling
> all
> the old dried out bags around the studio and I guess some low fire
> clay
> got mixed in. The lowfire clay is distributed in varying quantities
> thru out many of the pots, but that is a simple issue to avoid in the
> future.
>
> I would like a little clarification regarding the reduction
> comments you
> made below. In one case you are talking about the flame being hungry
> for oxygen and it taking it from the ware. I assume you are
> speaking of
> "body reduction" at this point. I understand that that needs to
> happen
> before the glaze begins to liquefy, but why is it done other than to
> change the color of the underlaying clay body? In your second comment
> you seem to be talking about body reduction again, yes?
>
> I am still not clear about the reduction with the glaze and when this
> should be happening. Can you do body reduction, go back to an
> oxidizing
> atmosphere and then return to reduction at say ^9 for a ^10 firing, or
> does the kiln need to be in reduction during the entire process of
> glass
> formation?
>
> Thanks,
>
> Frank
>
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