maryhstudio Posted February 27, 2018 Report Share Posted February 27, 2018 I've been testing red glazes from recipes I've gotten on the web, and in cone 6 glaze books. tin, chrome, and copper, depending on the recipe. I follow each to the letter and fire at cone 6 oxidation in my electric kiln. They all come out GREEN!! What am I missing, or doing wrong? I bisque the test tiles which are made from cone 6 white clay, very porcelain-like. Any help or advice is appreciated (I am tearing my hair out... well, not literally!). Thanks! Link to comment Share on other sites More sharing options...
Min Posted February 27, 2018 Report Share Posted February 27, 2018 Chrome tin reds just need the tiniest bit of chrome, like in the range of 0 point 2 If you are making up a 100 gram test batch you need a well calibrated scale that can accurately do tenths of a gram. Sounds like you just used too much chrome for those tests. Copper reds are fired in reduction to get red, you will get green in an electric kiln. Welcome to the forums Link to comment Share on other sites More sharing options...
oldlady Posted February 27, 2018 Report Share Posted February 27, 2018 if you want a really red red, the color of a valentine heart, you can get commercial glazes in bottles to fire at cone 6 in an oxidation firing in an electric kiln. i would never use that kind on the interior of a piece that will hold food because the color probably comes from cadmium. you cannot guarantee that your particular piece is safe to use for food because you probably do not have exquisite control over your firing. as Min, the glaze guru says, the recipes you are following are made for reduction firing, something that cannot be done in a normal electric kiln without ruining it. Link to comment Share on other sites More sharing options...
Min Posted February 28, 2018 Report Share Posted February 28, 2018 1 hour ago, oldlady said: the recipes you are following are made for reduction firing, something that cannot be done in a normal electric kiln without ruining it. Guess I didn't write very clearly in my first post, chrome tin reds work in electric kilns, just have to have a compatible base recipe. Can get purple tones by using the same principle and adding a tiny bit of cobalt to the chrome/ tin red. Copper reds are done in reduction. Sorry for the confusion. Link to comment Share on other sites More sharing options...
maryhstudio Posted February 28, 2018 Author Report Share Posted February 28, 2018 5 hours ago, Min said: Chrome tin reds just need the tiniest bit of chrome, like in the range of 0 point 2 If you are making up a 100 gram test batch you need a well calibrated scale that can accurately do tenths of a gram. Sounds like you just used too much chrome for those tests. Copper reds are fired in reduction to get red, you will get green in an electric kiln. Welcome to the forums Thanks Min! So I can't get a good red in oxidation? I've been doing this for a long time, but have purchased a lot of my glazes, and also made some successful ones myself, but red has been a rel challenge. Link to comment Share on other sites More sharing options...
maryhstudio Posted February 28, 2018 Author Report Share Posted February 28, 2018 4 hours ago, oldlady said: if you want a really red red, the color of a valentine heart, you can get commercial glazes in bottles to fire at cone 6 in an oxidation firing in an electric kiln. i would never use that kind on the interior of a piece that will hold food because the color probably comes from cadmium. you cannot guarantee that your particular piece is safe to use for food because you probably do not have exquisite control over your firing. as Min, the glaze guru says, the recipes you are following are made for reduction firing, something that cannot be done in a normal electric kiln without ruining it. What about making a red glaze with a cone 6 abase glaze and adding a mason stain for the color? Link to comment Share on other sites More sharing options...
neilestrick Posted February 28, 2018 Report Share Posted February 28, 2018 You can get a pretty good red with chrome/tin. It will always be a little to the raspberry side, though, not a blood red. Also, because of the tin, the glaze will be opaque, so it won't have the depth of color like a copper red. If you want to get really technical, you could work on a copper red using silicon carbide for localized reduction. Tom Turner did a lot of work with that method, and said he had better results than in the gas kiln. You should be able to find his paper on it with a little Google searching. Link to comment Share on other sites More sharing options...
why_not Posted February 28, 2018 Report Share Posted February 28, 2018 I have recently carried out some successful trials using saggars to produce cone 6 copper red reduction glazes in an electric kiln. I generated a reduction atmosphere by adding a small amount of black iron oxide mixed with powdered charcoal to the bottom of a saggar with a test piece painted with Selsor Red (formula see J. Britt - The Complete Guide to Mid-range Glazes pg 100). The iron oxide/charcoal mixture produced a reducing carbon monoxide atmosphere within the saggar during firing to cone 6 which turned the glaze oxblood red (see attached photo). The atmospere within the kiln remained oxidizing as witnessed by the fact that test patchs of the same glaze , on the outside of the saggar, remained green. I am currently planning further trials. Link to comment Share on other sites More sharing options...
Min Posted February 28, 2018 Report Share Posted February 28, 2018 16 hours ago, maryhstudio said: So I can't get a good red in oxidation? Yes you can, I think you probably just made an error with measuring out the chrome with your chrome tin red. Base glaze has to have lots of calcium and zero zinc and lowish alumina. Link to comment Share on other sites More sharing options...
maryhstudio Posted February 28, 2018 Author Report Share Posted February 28, 2018 18 hours ago, neilestrick said: You can get a pretty good red with chrome/tin. It will always be a little to the raspberry side, though, not a blood red. Also, because of the tin, the glaze will be opaque, so it won't have the depth of color like a copper red. If you want to get really technical, you could work on a copper red using silicon carbide for localized reduction. Tom Turner did a lot of work with that method, and said he had better results than in the gas kiln. You should be able to find his paper on it with a little Google searching. Thanks for the tip! Link to comment Share on other sites More sharing options...
maryhstudio Posted February 28, 2018 Author Report Share Posted February 28, 2018 Just now, maryhstudio said: Thanks for the tip! Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2018 Report Share Posted March 3, 2018 that is impressive. The liver color comes from not reoxidizing after reduction. You could try using a slightly thinner application for this one. I gave John Britt all the glazes we used at Montana State University-Billings from 1980-2000 for ^6 reduction when I reduced the firing temperature for classes.. This red was a good one. He has tweaked many of them for his book. If you go to my gallery I have the raspberry recipe posted beneath the photo. I believe it is under the album Forum discussions. Marcia Selsor Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2018 Report Share Posted March 3, 2018 http://community.ceramicartsdaily.org/gallery/image/765-6-red-glaze-with-6006-deep-crimson/ here is the link to red crimson ^6 electric <- aka Oxidation. http://community.ceramicartsdaily.org/gallery/image/765-6-red-glaze-with-6006-deep-crimson/ it wasn't easy to post! Marcia Link to comment Share on other sites More sharing options...
maryhstudio Posted March 3, 2018 Author Report Share Posted March 3, 2018 3 hours ago, Marcia Selsor said: that is impressive. The liver color comes from not reoxidizing after reduction. You could try using a slightly thinner application for this one. I gave John Britt all the glazes we used at Montana State University-Billings from 1980-2000 for ^6 reduction when I reduced the firing temperature for classes.. This red was a good one. He has tweaked many of them for his book. If you go to my gallery I have the raspberry recipe posted beneath the photo. I believe it is under the album Forum discussions. Marcia Selsor Thanks Marcia, but I’m looking for a cone 6 oxidation red ! I shan’t give up... Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2018 Report Share Posted March 3, 2018 raspberry IS OXIDATION take a look. Cant repost the url for some reason by the one above has w photo of Raspberry which is a nice RED ^6 OXIDATION glaze. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2018 Report Share Posted March 3, 2018 here is a red ^6 Oxidation glaze. Th recipe is in my gallery under forum discussions. The tin and chrome are in the stain. Recipe ^6 Oxidation red This is using 10% deep crimson Mason stain in a glaze altered by Ron Roy for Sue Hintz Version#2 ^6 OXIDATION Cornwall Stone 33.5 G200 22 Whiting 18 Ger. Borate 10 EPK 5.5 Silica 11 Bentonite 2 Mason Stain Deep Crimson 10% Link to comment Share on other sites More sharing options...
oldlady Posted March 3, 2018 Report Share Posted March 3, 2018 did not find that heading on your website. was i looking in the right place? Link to comment Share on other sites More sharing options...
Min Posted March 3, 2018 Report Share Posted March 3, 2018 @oldlady, go to Marcia's homepage on this forum, then go to her gallery tab. On page 3 of Marcia's gallery there is an album called "forum discussions", the recipe is there, first comment under the picture of the red pot. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2018 Report Share Posted March 3, 2018 1 hour ago, oldlady said: did not find that heading on your website. was i looking in the right place? it is on THIS website under members gallery. Follow Min's directions. Marcia Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 3, 2018 Report Share Posted March 3, 2018 23 hours ago, Marcia Selsor said: http://community.ceramicartsdaily.org/gallery/image/765-6-red-glaze-with-6006-deep-crimson/ here is the link to red crimson ^6 electric <- aka Oxidation. http://community.ceramicartsdaily.org/gallery/image/765-6-red-glaze-with-6006-deep-crimson/ it wasn't easy to post! Marcia click on the first link and scroll down to comments for the recipe. . Link to comment Share on other sites More sharing options...
Tamas Posted May 30, 2018 Report Share Posted May 30, 2018 On 2/28/2018 at 6:35 PM, why_not said: I have recently carried out some successful trials using saggars to produce cone 6 copper red reduction glazes in an electric kiln. I generated a reduction atmosphere by adding a small amount of black iron oxide mixed with powdered charcoal to the bottom of a saggar with a test piece painted with Selsor Red (formula see J. Britt - The Complete Guide to Mid-range Glazes pg 100). The iron oxide/charcoal mixture produced a reducing carbon monoxide atmosphere within the saggar during firing to cone 6 which turned the glaze oxblood red (see attached photo). The atmospere within the kiln remained oxidizing as witnessed by the fact that test patchs of the same glaze , on the outside of the saggar, remained green. I am currently planning further trials. Hi why-not, thanks for sharing this - your post has inspired me to try the same in my electric kiln - and to my amazement it worked :) I must have put in a bit too much charcoal as I had know idea about the amount required. But the results are promising, here's a dark celadon and a copper red tile. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted May 30, 2018 Report Share Posted May 30, 2018 great experiment! Congrats. I think porcelain is a better background for the red glaze. An iron bearing stoneware will make it more liver color red. Just saying from experience. Marcia Link to comment Share on other sites More sharing options...
Tamas Posted May 30, 2018 Report Share Posted May 30, 2018 1 hour ago, Marcia Selsor said: great experiment! Congrats. I think porcelain is a better background for the red glaze. An iron bearing stoneware will make it more liver color red. Just saying from experience. Marcia Thank you, yes, the next step is indeed to try it on different bodies, and on actual pots. Link to comment Share on other sites More sharing options...
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