Jump to content


Photo

Randy's Red - Cone 5 Glaze


  • Please log in to reply
17 replies to this topic

#1 Sharron F

Sharron F

    Newbie

  • Members
  • Pip
  • 1 posts
  • LocationConnecticut

Posted 23 May 2010 - 08:06 AM

I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.

#2 hansen

hansen

    Advanced Member

  • Members
  • PipPipPip
  • 121 posts
  • LocationAlexandria, Virginia

Posted 23 May 2010 - 12:13 PM

I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.

The reports I have heard about this glaze, and most iron reds and tomato reds, you fire to temp, hold, ramp it down, or whatever you do, then before it goes cold, refire to cone 05
h a n s e n



h a n s e n
Stone House Studio, Alexandria, Virginia

americanpotter.blogspot.com
thesuddenschool.blogspot.com

#3 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,741 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 02 July 2010 - 06:08 AM

I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I agree. Holding the temperature even only for 20 minutes at ^6 and again at 1825 will make a big difference. Also muddy color is when it is a little thick. This is a touchy glaze. A thin but not too thin coat really goes red. One of my kilns has a cone setter. I just push the button back on and hold it at the high temp. for 20 minutes and let it drop. Then turn it back on again at 1825. If I miss it, I just turn it back on and take it up to that temperature and hold. I haven't held it for more than 30 minutes.

#4 hansen

hansen

    Advanced Member

  • Members
  • PipPipPip
  • 121 posts
  • LocationAlexandria, Virginia

Posted 06 July 2010 - 05:29 AM


I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I agree. Holding the temperature even only for 20 minutes at ^6 and again at 1825 will make a big difference. Also muddy color is when it is a little thick. This is a touchy glaze. A thin but not too thin coat really goes red. One of my kilns has a cone setter. I just push the button back on and hold it at the high temp. for 20 minutes and let it drop. Then turn it back on again at 1825. If I miss it, I just turn it back on and take it up to that temperature and hold. I haven't held it for more than 30 minutes.


What happens in iron red glazes is that unless "bumped" or re-fired they come out brown. Because the cooling is too fast for iron to form the red coloration on the surface of the pot. Sometimes adding more bone ash in these glazes helps, so i am told. Does this help? The way it was first told to me is to cool it to very dull red then bump it back to cherry red, but nowadays we don't look into the kilns which is a unsafe practice, do we?



h a n s e n
Stone House Studio, Alexandria, Virginia

americanpotter.blogspot.com
thesuddenschool.blogspot.com

#5 Jennie Chien

Jennie Chien

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 07 July 2010 - 06:00 PM

I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I mix glazes for a local art center and just recently discovered that if you use Special red iron oxide (much redder and much more expensive) the Randy's will be red, sometimes tomato red with blacks and blues. For years we only got browns until I changed the RIO. No need to worry about holding, etc. as we fire 3 different kilns, all to cone 6. Results vary by kiln but all come out red.

#6 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,741 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 07 July 2010 - 08:18 PM



I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I agree. Holding the temperature even only for 20 minutes at ^6 and again at 1825 will make a big difference. Also muddy color is when it is a little thick. This is a touchy glaze. A thin but not too thin coat really goes red. One of my kilns has a cone setter. I just push the button back on and hold it at the high temp. for 20 minutes and let it drop. Then turn it back on again at 1825. If I miss it, I just turn it back on and take it up to that temperature and hold. I haven't held it for more than 30 minutes.


What happens in iron red glazes is that unless "bumped" or re-fired they come out brown. Because the cooling is too fast for iron to form the red coloration on the surface of the pot. Sometimes adding more bone ash in these glazes helps, so i am told. Does this help? The way it was first told to me is to cool it to very dull red then bump it back to cherry red, but nowadays we don't look into the kilns which is a unsafe practice, do we?


I am using a slightly different ^6 oxidation red from Michael Bailey's book.
I don't refire to ^05., I just hold the kiln at ^6 then again at 1825. If I miss that temperature as it is dropping, I turn the kiln back on, say..at 1700, and take it back up to 1825 and hold for 20-30 minutes. I am getting nice reds. But, if the glaze is on just a little thick, it will go brown.

#7 hansen

hansen

    Advanced Member

  • Members
  • PipPipPip
  • 121 posts
  • LocationAlexandria, Virginia

Posted 09 July 2010 - 05:02 AM

yeah and if your recipe has bone ash sometimes increasing the bone ash is known to make red redder




I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I agree. Holding the temperature even only for 20 minutes at ^6 and again at 1825 will make a big difference. Also muddy color is when it is a little thick. This is a touchy glaze. A thin but not too thin coat really goes red. One of my kilns has a cone setter. I just push the button back on and hold it at the high temp. for 20 minutes and let it drop. Then turn it back on again at 1825. If I miss it, I just turn it back on and take it up to that temperature and hold. I haven't held it for more than 30 minutes.


What happens in iron red glazes is that unless "bumped" or re-fired they come out brown. Because the cooling is too fast for iron to form the red coloration on the surface of the pot. Sometimes adding more bone ash in these glazes helps, so i am told. Does this help? The way it was first told to me is to cool it to very dull red then bump it back to cherry red, but nowadays we don't look into the kilns which is a unsafe practice, do we?


I am using a slightly different ^6 oxidation red from Michael Bailey's book.
I don't refire to ^05., I just hold the kiln at ^6 then again at 1825. If I miss that temperature as it is dropping, I turn the kiln back on, say..at 1700, and take it back up to 1825 and hold for 20-30 minutes. I am getting nice reds. But, if the glaze is on just a little thick, it will go brown.




h a n s e n
Stone House Studio, Alexandria, Virginia

americanpotter.blogspot.com
thesuddenschool.blogspot.com

#8 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,741 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 09 July 2010 - 06:38 AM


I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I mix glazes for a local art center and just recently discovered that if you use Special red iron oxide (much redder and much more expensive) the Randy's will be red, sometimes tomato red with blacks and blues. For years we only got browns until I changed the RIO. No need to worry about holding, etc. as we fire 3 different kilns, all to cone 6. Results vary by kiln but all come out red.


What kind of RIO are you using that is so much redder than RIO that isn't so red? Crocus Martis is purplish. Spanish red iron oxide is fine red. Could you specify what it is you are using? I have three RIOs in my studio, plus Black Iron Oxide.
Inquiring minds want to know.
Thanks.

#9 Jennie Chien

Jennie Chien

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 12 July 2010 - 03:32 PM



I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I mix glazes for a local art center and just recently discovered that if you use Special red iron oxide (much redder and much more expensive) the Randy's will be red, sometimes tomato red with blacks and blues. For years we only got browns until I changed the RIO. No need to worry about holding, etc. as we fire 3 different kilns, all to cone 6. Results vary by kiln but all come out red.


What kind of RIO are you using that is so much redder than RIO that isn't so red? Crocus Martis is purplish. Spanish red iron oxide is fine red. Could you specify what it is you are using? I have three RIOs in my studio, plus Black Iron Oxide.
Inquiring minds want to know.
Thanks.


The redder RIO is called SPECIAL and we order from Ceramic Supply of New York and New Jersey (http://www.7ceramic.com/). You can call them and ask what makes it different but my guess is taht it is purer. (Ceramic Supply Inc, 7 Route 46 West, Lodi, NJ 07644, 973.340.3005, 800-723-7264). They are owned by Standard Clay in PA.

Special RIO costs much more than regular Spanish RIO. Eg 5 lb of Special is $13.50 and 5 lb vs 5 lb Spanish at $4.05. We use that cheaper Spanish RIO in glazes like Ron Roy Black #3 and Floating Blue (makes better blues). Overall, Special makes a redder cast in glazes but strangely makes the Floating Blue flatter, with green highlights in it more than blue. It's actually nice but students at the art center want BLUE.

Another tip, Dark Rutile works much better in Floating Blue than Light Rutile. Lt Rutile made the FB whiter and sort of flat looking. My guess is that less pure ingredients in FB make more textures in the melt. More pure will flatten it out.

Additionally, Special RIO will also make your red brown slips stay redder vs going dark brown at cone 6. Not sure what happens at Cone 10 gas reduction firings as never used it for our cone 10 glazes. I suspect that the higher temp and reduction will brown it out anyway so no reason to use something that costs 3x as much for the same effect.

Have not tried crocus martis as it is even MORE expensive than the Special. Hope that helps answer your questions.

#10 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,741 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 15 July 2010 - 03:06 PM




I have mixed a batch of Randy's Red - Cone 5 Glaze. I am getting more of a muddy brown than reddish brown. If anyone has used this common recipe - do you have any thoughts on how to adjust recipe to get the "red' back.


I mix glazes for a local art center and just recently discovered that if you use Special red iron oxide (much redder and much more expensive) the Randy's will be red, sometimes tomato red with blacks and blues. For years we only got browns until I changed the RIO. No need to worry about holding, etc. as we fire 3 different kilns, all to cone 6. Results vary by kiln but all come out red.


What kind of RIO are you using that is so much redder than RIO that isn't so red? Crocus Martis is purplish. Spanish red iron oxide is fine red. Could you specify what it is you are using? I have three RIOs in my studio, plus Black Iron Oxide.
Inquiring minds want to know.
Thanks.


The redder RIO is called SPECIAL and we order from Ceramic Supply of New York and New Jersey (http://www.7ceramic.com/). You can call them and ask what makes it different but my guess is taht it is purer. (Ceramic Supply Inc, 7 Route 46 West, Lodi, NJ 07644, 973.340.3005, 800-723-7264). They are owned by Standard Clay in PA.

Special RIO costs much more than regular Spanish RIO. Eg 5 lb of Special is $13.50 and 5 lb vs 5 lb Spanish at $4.05. We use that cheaper Spanish RIO in glazes like Ron Roy Black #3 and Floating Blue (makes better blues). Overall, Special makes a redder cast in glazes but strangely makes the Floating Blue flatter, with green highlights in it more than blue. It's actually nice but students at the art center want BLUE.

Another tip, Dark Rutile works much better in Floating Blue than Light Rutile. Lt Rutile made the FB whiter and sort of flat looking. My guess is that less pure ingredients in FB make more textures in the melt. More pure will flatten it out.

Additionally, Special RIO will also make your red brown slips stay redder vs going dark brown at cone 6. Not sure what happens at Cone 10 gas reduction firings as never used it for our cone 10 glazes. I suspect that the higher temp and reduction will brown it out anyway so no reason to use something that costs 3x as much for the same effect.

Have not tried crocus martis as it is even MORE expensive than the Special. Hope that helps answer your questions.

Thanks.
I have three RIO in my studio plus a little crocus martis, plus Black iron oxide.
I'll have to do some tests and see if one works better than another. Thanks for your explanantion.





#11 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,741 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 21 December 2011 - 09:18 AM

This is a view of Michael Bailey's Iron Red fired to ^6 Ox. and held at about 1950 for 30 minutes.
http://ceramicartsda...ewimage&img=682
Take a good look at the bottom glaze on the mug. It is a nice iron red.
Marcia

#12 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 1,898 posts
  • LocationCentral, PA

Posted 21 December 2011 - 11:25 AM

This is a view of Michael Bailey's Iron Red fired to ^6 Ox. and held at about 1950 for 30 minutes.
http://ceramicartsda...ewimage&img=682
Take a good look at the bottom glaze on the mug. It is a nice iron red.
Marcia


I used a commercial Iron Red for years at the HS. It was from Minnesota Clay. It was very thickness dependent. If you got it on thin it was a gloss brown black, thicker it became red with light speckling of olive green, thicker yet it got more olive greens in it but still stayed red. It was one of my favorite glazes as once we got used to it- it was always successful.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#13 catsandgoddess

catsandgoddess

    Newbie

  • Members
  • Pip
  • 1 posts

Posted 28 December 2011 - 10:28 PM


This is a view of Michael Bailey's Iron Red fired to ^6 Ox. and held at about 1950 for 30 minutes.
http://ceramicartsda...ewimage&img=682
Take a good look at the bottom glaze on the mug. It is a nice iron red.
Marcia


I used a commercial Iron Red for years at the HS. It was from Minnesota Clay. It was very thickness dependent. If you got it on thin it was a gloss brown black, thicker it became red with light speckling of olive green, thicker yet it got more olive greens in it but still stayed red. It was one of my favorite glazes as once we got used to it- it was always successful.




Hi, I would love to have a good Randy's Red recipe if anyone would care to contribute one. :-)

thx,
Catsandgoddess@gmail.com

#14 Jennie Chien

Jennie Chien

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 28 January 2012 - 08:29 PM


Just found my Randy's Red formula we use in the art center. Very different from the other one I sent you earlier. We fire in Tucker's ConeArt kiln with 3 inch thick walls. Fires hotter than we like as will cause running at Cone 6 (by their electronic controller), so knocked back Cone 6 temp by 30 degrees. Cools very slowly. When same glaze is fired in older kilnsitter kiln, glaze will be browner definitely. Can try refiring to bisque Cone 06 but that doesn't always work. I think hotter is better and Cone 5 just isn't hot enough.


Percent
24 Flint/Silica
4 EPK
8 Soda Ash
25.6 Gerstley Borate
16 F4 SPAR
14 TALC
12.12 RIO
1 Bentonite


FYI Adds up over 100.

Different formula, not tested but note that must fire hot.
[Randy’s Red (in grams) Low Cone 7 or hot Cone 6Flint 75.00 grams

EPK 12.50

F-4 spar 50.00

Talc 35.00

Gerstley Borate 80.00

252.50 grams

+RIO 37.80 (this is 15%)

(red iron oxide)




canyon fox has sent you this email from http://ceramicartsda...unity/index.php.


Hi Jennie,
thank you for sharing about SPECIAL red iron oxide.
I ordered one and tried with two recipes I have and still got just muddy brown, almost black. Would you share your "reddest" recipe please? I fire to cone 5.
Thank you,
Lena

---------------------------------------------------



#15 trorison

trorison

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 29 January 2012 - 05:04 PM


Just found my Randy's Red formula we use in the art center. Very different from the other one I sent you earlier. We fire in Tucker's ConeArt kiln with 3 inch thick walls. Fires hotter than we like as will cause running at Cone 6 (by their electronic controller), so knocked back Cone 6 temp by 30 degrees. Cools very slowly. When same glaze is fired in older kilnsitter kiln, glaze will be browner definitely. Can try refiring to bisque Cone 06 but that doesn't always work. I think hotter is better and Cone 5 just isn't hot enough.


Percent
24 Flint/Silica
4 EPK
8 Soda Ash
25.6 Gerstley Borate
16 F4 SPAR
14 TALC
12.12 RIO
1 Bentonite


FYI Adds up over 100.

Different formula, not tested but note that must fire hot.
[Randy’s Red (in grams) Low Cone 7 or hot Cone 6Flint 75.00 grams

EPK 12.50

F-4 spar 50.00

Talc 35.00

Gerstley Borate 80.00

252.50 grams

+RIO 37.80 (this is 15%)

(red iron oxide)




canyon fox has sent you this email from http://ceramicartsda...unity/index.php.


Hi Jennie,
thank you for sharing about SPECIAL red iron oxide.
I ordered one and tried with two recipes I have and still got just muddy brown, almost black. Would you share your "reddest" recipe please? I fire to cone 5.
Thank you,
Lena

---------------------------------------------------



Try this link to see the difference in iron reds with and without cooling cycle. There are formulas and the firing cycle given. http://wpapotters.bl...ts-group-5.html

#16 jd53

jd53

    Member

  • Members
  • PipPip
  • 18 posts
  • LocationNH usa

Posted 29 January 2012 - 05:21 PM

Trorison

thanks for that link

very good info, and some good looking pots

jeff

#17 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,741 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 31 January 2012 - 04:32 PM

Michael Bailey's recipe
I always understood here was a need for bone ash in Iron reds. I don't see that in some of the opted recipes.
But if it works then great. In Michael Bailey's cone 6 Oxidation book he provides many variation with additions from 0 up to 23% red Iron Oxide with the color transitions from
white through yellow , tan brown speckled, with the brightest reds in the 11%-18% range. Here is the recipe:
Bailey's Orange red Base Glaze
Potash Feldspar 46.7
Kaolin 4
Bentonite 2
Bone Ash 15
Lithium Carb. 4
Talc 16.9
Silica 11.4
total 100.0

Red Iron Oxide 11.5%

I soak it at ^6 for about 20 minutes and drop to 1900 for 30 minutes soak. see on the bottom of mug here
chttp://ceramicartsda...ewimage&img=682

#18 canyon fox

canyon fox

    Member

  • Members
  • PipPip
  • 23 posts

Posted 05 March 2012 - 05:12 PM

Michael Bailey's recipe
I always understood here was a need for bone ash in Iron reds. I don't see that in some of the opted recipes.
But if it works then great. In Michael Bailey's cone 6 Oxidation book he provides many variation with additions from 0 up to 23% red Iron Oxide with the color transitions from
white through yellow , tan brown speckled, with the brightest reds in the 11%-18% range. Here is the recipe:
Bailey's Orange red Base Glaze
Potash Feldspar 46.7
Kaolin 4
Bentonite 2
Bone Ash 15
Lithium Carb. 4
Talc 16.9
Silica 11.4
total 100.0

Red Iron Oxide 11.5%

I soak it at ^6 for about 20 minutes and drop to 1900 for 30 minutes soak. see on the bottom of mug here
chttp://ceramicartsda...ewimage&img=682


Thank you for sharing the recipe, Marcia.
It's hard to see, is your red matte or glossy?




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users