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Steven Hill's Firing Schedule For Bisque?


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#41 Wyndham

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Posted 25 May 2013 - 03:10 PM

This has been a great thread on so many levels. There's a lot of information to be learned here.

I've come in a bit late to the conversation but thought of something from a article from many years ago. The article dealt with the color of certain iron glazes and one that would change from a deep iron red(Bailey's ) to a light yellow red.
The author said to refire to 06 to get a very light colored iron glaze. This was back around 1986-1990 in CM I think but I remember trying it at the time and it did lighten up the color.

I have a thought that we might be hitting near a sweet spot in the 1500-1800 f range. Because of the different recipes that elusive bright iron red is different for each kiln and potter.

I wonder if a firing that brought the ramp back up after the low 1600-1700 back to 1800 or so and held for some time, before shutting down might not produce some interesting effects.

Wyndham

#42 OffCenter

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Posted 25 May 2013 - 05:39 PM

I wonder if a firing that brought the ramp back up after the low 1600-1700 back to 1800 or so and held for some time, before shutting down might not produce some interesting effects.

Wyndham


If you try it please let us know the results.

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#43 John255

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Posted 25 May 2013 - 06:15 PM

Wyndham,
Welcome to the conversation.
Yes, by all means share your discoveries.
Since I started this thread I've found a small used computer controlled Olympic kiln for testing.
Tomorrow will be first slow cool firing with samples of Bailey Red and others.
It will also be a first trial for Spanish red iron, and with, and without synthetic Bone Ash.
At the same time my neighbor will be firing samples from same glaze batch, but with normal cooling.
May have to start another thread with results?
Regards,
John255



John255

#44 Min

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Posted 25 May 2013 - 07:36 PM

Following link is an article on slow cooling iron reds. I believe the SCM makes a big difference in the colour outcome, might be worth testing over that with different ramps also.

http://ceramicartsda...ion-in-cooling/

Min

#45 John255

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Posted 25 May 2013 - 08:23 PM

Yes, we looked at that in post #4.
I agree.
The first ramp I'm interested in is holding one hour at the top without over firing ^6.
The comments by Kate at end of article were also interesting. Photos would have cushioned the brag.
However, even Dr. Marins does not claim to know whats happening chemically in the liquid state.
Is there a more efficient way?
Five hours around 1600F is a long time.
Is time part of the art like Bonsai? I don't know.
John255

John255

#46 John255

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Posted 03 June 2013 - 11:32 AM

I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255



Attached Files


John255

#47 OffCenter

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Posted 03 June 2013 - 12:16 PM

I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255



I've given up (for the time being) on Bailey's Red. Right now I'm getting good results with Juicy Fruit over SCM warm. I subbed Spanish RIO for the RIO in JF. Here is a pitcher (two views) that I unloaded this morning: http://ceramicartsda...wimage&img=2641

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#48 Mart

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Posted 03 June 2013 - 12:43 PM

I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255


Why not try a really thick one too. Maybe 3 mm or even more? If you do not get the red, you get nice dark black.

#49 OffCenter

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Posted 03 June 2013 - 12:51 PM

I don't think thicker will help. If trying to get your BR to look like Hill's, you should spray it over sprayed SCM warm. Vary the thickness of both. You'll need something bigger than a test tile.

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#50 Min

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Posted 03 June 2013 - 01:13 PM

I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255




Hi John,


Hmm, isn't glaze testing fun? I pulled out my Michael Bailey Glazes book and had another look at what he wrote about iron. Apologies if you have already read this, he states that the strength of the iron is the most important thing in the glaze and the one he used for the example in his book produced "greens and greeny browns up to7%, bright orange at 10 to 13% with a gradual transition from orange to dark satin brown at 24%". That being said, none of his lower rio sample tiles have the hares fur of green that yours show. It also appears that your tests are more of a gloss glaze finish than the satin finish I get from iron reds.

The test tile below is a tweaked version of VanGilders Iron Red, the top third of the tile has 3 dips of glaze, no trace of green fur. Let me know if you want the recipe, I tweaked it to lower the expansion to fit my clay better. Do you have access to other types of iron or from other suppliers? If you like I can scan the couple pages in Bailey's book and email it to you. (I used the S.Hill slow cool down ramp on the tile below.)

Min

Attached Files



#51 OffCenter

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Posted 03 June 2013 - 01:43 PM


I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255




Hi John,


Hmm, isn't glaze testing fun? I pulled out my Michael Bailey Glazes book and had another look at what he wrote about iron. Apologies if you have already read this, he states that the strength of the iron is the most important thing in the glaze and the one he used for the example in his book produced "greens and greeny browns up to7%, bright orange at 10 to 13% with a gradual transition from orange to dark satin brown at 24%". That being said, none of his lower rio sample tiles have the hares fur of green that yours show. It also appears that your tests are more of a gloss glaze finish than the satin finish I get from iron reds.

The test tile below is a tweaked version of VanGilders Iron Red, the top third of the tile has 3 dips of glaze, no trace of green fur. Let me know if you want the recipe, I tweaked it to lower the expansion to fit my clay better. Do you have access to other types of iron or from other suppliers? If you like I can scan the couple pages in Bailey's book and email it to you. (I used the S.Hill slow cool down ramp on the tile below.)

Min


It looks pretty good at the bottom but there is so much glare you can't really see the glaze well enough to know what it really looks like. Got a better pic?

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#52 Wyndham

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Posted 03 June 2013 - 01:49 PM

I want to share something I tested many years ago. I was wondering what the difference was between light & dark rutile, mainly because light rutile cost more.
On a whim, I put a batch of dark rutile in a bisked bowl and fired it with the other greenware to Cone 06 bisk. The result was light rutile.

What does this have to do with the iron we use, well I don't know but I think I might fire some red iron oxide like I did with the rutile and see if there is a difference. I might have to fire the iron at a lower temp, around 1200 f as I'm not sure what temp iron starts to fuse, as I just want it to sinter the iron oxide.
I might even mix some bone ash in another test bowl and use these in some test.

Btw I had a kiln mishap where my 220 leads into the kiln shorted, so I have some rewiring to do before I can test. not a big issue just a tedious, job I'm putting off for a awhile.

Later Wyndham

#53 Min

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Posted 03 June 2013 - 02:37 PM



I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255




Hi John,


Hmm, isn't glaze testing fun? I pulled out my Michael Bailey Glazes book and had another look at what he wrote about iron. Apologies if you have already read this, he states that the strength of the iron is the most important thing in the glaze and the one he used for the example in his book produced "greens and greeny browns up to7%, bright orange at 10 to 13% with a gradual transition from orange to dark satin brown at 24%". That being said, none of his lower rio sample tiles have the hares fur of green that yours show. It also appears that your tests are more of a gloss glaze finish than the satin finish I get from iron reds.

The test tile below is a tweaked version of VanGilders Iron Red, the top third of the tile has 3 dips of glaze, no trace of green fur. Let me know if you want the recipe, I tweaked it to lower the expansion to fit my clay better. Do you have access to other types of iron or from other suppliers? If you like I can scan the couple pages in Bailey's book and email it to you. (I used the S.Hill slow cool down ramp on the tile below.)

Min


It looks pretty good at the bottom but there is so much glare you can't really see the glaze well enough to know what it really looks like. Got a better pic?

Jim

Sorry about the last pic, had the flash on. I agree with Jim's earlier post about needing to spray the red over SCM to get S.Hill's tones. - Min

Attached Files



#54 OffCenter

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Posted 03 June 2013 - 04:21 PM




I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255




Hi John,


Hmm, isn't glaze testing fun? I pulled out my Michael Bailey Glazes book and had another look at what he wrote about iron. Apologies if you have already read this, he states that the strength of the iron is the most important thing in the glaze and the one he used for the example in his book produced "greens and greeny browns up to7%, bright orange at 10 to 13% with a gradual transition from orange to dark satin brown at 24%". That being said, none of his lower rio sample tiles have the hares fur of green that yours show. It also appears that your tests are more of a gloss glaze finish than the satin finish I get from iron reds.

The test tile below is a tweaked version of VanGilders Iron Red, the top third of the tile has 3 dips of glaze, no trace of green fur. Let me know if you want the recipe, I tweaked it to lower the expansion to fit my clay better. Do you have access to other types of iron or from other suppliers? If you like I can scan the couple pages in Bailey's book and email it to you. (I used the S.Hill slow cool down ramp on the tile below.)

Min


It looks pretty good at the bottom but there is so much glare you can't really see the glaze well enough to know what it really looks like. Got a better pic?

Jim

Sorry about the last pic, had the flash on. I agree with Jim's earlier post about needing to spray the red over SCM to get S.Hill's tones. - Min


That's getting close to a really nice rich red. I imagine it looks even better over a larger area and over SCM.

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#55 John255

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Posted 03 June 2013 - 05:18 PM


I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255



I've given up (for the time being) on Bailey's Red. Right now I'm getting good results with Juicy Fruit over SCM warm. I subbed Spanish RIO for the RIO in JF. Here is a pitcher (two views) that I unloaded this morning: http://ceramicartsda...wimage&img=2641

Jim


Jim,
Beautiful result on your pitchers.
Attached is what my Juicy Fruit looks like on SCM.
On SH's DVD he emphasized that 60% of the glaze thickness on his pots is SCM.
I followed that and sprayed it on rather thick.
It flowed on all samples, but was quite dry to the touch.
If Min is right about the Iron being weak that could be part of the failure.
Thanks for your input.
John255


Attached Files


John255

#56 John255

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Posted 03 June 2013 - 05:26 PM


I finished my first slow firing of SH glazes yesterday with results not even close.
However, I'd be grateful to hear opinions on Baileys Red first.
The firing schedule followed SH's for bisqued as supplied by Min on page one post two of this thread.
The formula for Baileys also supplied by Min on page two post, #28 was followed using Spanish Red Iron.
Only possible difference was synthetic Bone Ash was used instead of natural Bone Ash.
I could not find any reference that advised either type for iron reds.
The fast sample was fired in a neighbors kiln who used the Dawson sitter and no soaking or slow cooling.
The photo shows the slow sample trying to go red on the edges where glaze was thin.
There are also some speckles of red that appear to be crystals on the slow sample.
Both were dipped in same batch, and the only idea I have is to try it thinner, but it is already not very thick.
Thanks.
John255




Hi John,


Hmm, isn't glaze testing fun? I pulled out my Michael Bailey Glazes book and had another look at what he wrote about iron. Apologies if you have already read this, he states that the strength of the iron is the most important thing in the glaze and the one he used for the example in his book produced "greens and greeny browns up to7%, bright orange at 10 to 13% with a gradual transition from orange to dark satin brown at 24%". That being said, none of his lower rio sample tiles have the hares fur of green that yours show. It also appears that your tests are more of a gloss glaze finish than the satin finish I get from iron reds.

The test tile below is a tweaked version of VanGilders Iron Red, the top third of the tile has 3 dips of glaze, no trace of green fur. Let me know if you want the recipe, I tweaked it to lower the expansion to fit my clay better. Do you have access to other types of iron or from other suppliers? If you like I can scan the couple pages in Bailey's book and email it to you. (I used the S.Hill slow cool down ramp on the tile below.)

Min


Min,
Your test tile looks great.
That is a keen observation about the greenish streaks on my Bailey sample.
I wonder if we are sure Bailey is talking about oxidation. I know small amounts of iron in reduction goes green.
However it is a good point to pursue. I will do a line-blend of different irons in next firing.
I have VanGilders formula thank you. Will try that one too.
Thank you.
John255





John255

#57 John255

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Posted 03 June 2013 - 05:28 PM

I want to share something I tested many years ago. I was wondering what the difference was between light & dark rutile, mainly because light rutile cost more.
On a whim, I put a batch of dark rutile in a bisked bowl and fired it with the other greenware to Cone 06 bisk. The result was light rutile.

What does this have to do with the iron we use, well I don't know but I think I might fire some red iron oxide like I did with the rutile and see if there is a difference. I might have to fire the iron at a lower temp, around 1200 f as I'm not sure what temp iron starts to fuse, as I just want it to sinter the iron oxide.
I might even mix some bone ash in another test bowl and use these in some test.

Btw I had a kiln mishap where my 220 leads into the kiln shorted, so I have some rewiring to do before I can test. not a big issue just a tedious, job I'm putting off for a awhile.

Later Wyndham



Let us know how your iron test turns out.
Watch that 230V. It is lethal.
John255



John255

#58 John255

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Posted 03 June 2013 - 06:11 PM

I was a bit surprised to see the probably too thick SCM be so dry and yet running off the pots.
I also did some small tiles quickly dipping SCM to compare fired slow and fast cooling.
The attached shows SCM dipped in Baileys Red.
The slow cooled was a closer to red than any of the other pots in the firing.
Thanks for your thoughts.
John255

Attached Files


John255

#59 OffCenter

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Posted 03 June 2013 - 06:37 PM

I was a bit surprised to see the probably too thick SCM be so dry and yet running off the pots.
I also did some small tiles quickly dipping SCM to compare fired slow and fast cooling.
The attached shows SCM dipped in Baileys Red.
The slow cooled was a closer to red than any of the other pots in the firing.
Thanks for your thoughts.
John255


John, when you (and others here) say SCM I assume it is the "warm" version with yellow iron oxide. The "cool" version doesn't have yellow iron and is slightly different in base chems. It looks good under blues and greens but not under saturated irons. The test tile of slow fired Bailey's Red looks good except for the running. I like the color. I think the run is caused by both being too thick. It's almost impossible to get the same results dipping that you get spraying.

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#60 John255

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Posted 03 June 2013 - 06:49 PM


I was a bit surprised to see the probably too thick SCM be so dry and yet running off the pots.
I also did some small tiles quickly dipping SCM to compare fired slow and fast cooling.
The attached shows SCM dipped in Baileys Red.
The slow cooled was a closer to red than any of the other pots in the firing.
Thanks for your thoughts.
John255


John, when you (and others here) say SCM I assume it is the "warm" version with yellow iron oxide. The "cool" version doesn't have yellow iron and is slightly different in base chems. It looks good under blues and greens but not under saturated irons. The test tile of slow fired Bailey's Red looks good except for the running. I like the color. I think the run is caused by both being too thick. It's almost impossible to get the same results dipping that you get spraying.

Jim


Jim,
Yes your are right. I only used SCM warm with 2% yellow iron for this firing.
I was also getting acquainted with my first LPHV gravity feed spray gun.
I've been using syphon type for years and I will never think of going back.
I'm stunned by reduced amount of overspray, and the ease of use.
Should have done this years ago.
John255





John255




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