Marcia Selsor Posted December 3, 2013 Report Share Posted December 3, 2013 I fired some new pieces yesterday. I am experimenting with colors. Epsom salts and iron sulphate, cobalt sulphate, copper sulphate, Miracle grow for acid needy flowers, etc. Jan. 27 firings is the second group of 4.see the large pot in a later post or in my gallery. I love the colors! Link to comment Share on other sites More sharing options...
Kohaku Posted December 3, 2013 Report Share Posted December 3, 2013 Lovely. Whatever glaze (or sagger materials) you used on the center piece interacted with the burnishing particularly well. Link to comment Share on other sites More sharing options...
jrgpots Posted December 3, 2013 Report Share Posted December 3, 2013 They just seem to be getting better and better if that is possible. jed Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 3, 2013 Author Report Share Posted December 3, 2013 The center piece is cobalt sulphate with epsom salts solution.I like that one too.I am attempting to achieve color variation but with interesting graphic patterns pn the smooth surface. I find the orb form to be a satisfying "blank canvas". Marcia Link to comment Share on other sites More sharing options...
Evelyne Schoenmann Posted December 4, 2013 Report Share Posted December 4, 2013 Marcia, beautiful, as always. Kudos to you!! If ever you are doing an alternative firing course in Tuscany, book me in! So much to learn still and you are our alternative firing genius... Evelyne Link to comment Share on other sites More sharing options...
Benzine Posted December 4, 2013 Report Share Posted December 4, 2013 Great as always Marcia. Do all of those have Terra Sig on them? Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 4, 2013 Author Report Share Posted December 4, 2013 Yes they all have terra sig on them. Some are Coleman porcelain and some are Frost. Link to comment Share on other sites More sharing options...
Marc McMillan Posted December 4, 2013 Report Share Posted December 4, 2013 Excellent results as always. Are you creating a liquid out of the salts and appying it directly to the piece? I've been experimenting and had good results putting the materials in a foil pouch inside the piece and letting it fume onto the surface. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 4, 2013 Author Report Share Posted December 4, 2013 That sounds intriguing, Marc. I put some sawdust in one to blacken the inside and some of the top of the outside got black too. I want to try more with Epsom salts too. It seems to have strong interaction with the salts. Marcia Link to comment Share on other sites More sharing options...
oldlady Posted December 4, 2013 Report Share Posted December 4, 2013 great stuff, marcia. how about doing a video of the whole process? or have you done it and i just don't know it. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 5, 2013 Author Report Share Posted December 5, 2013 Ken Turner did the foil saggar section at the PC conference in Mn.Just as Sumi did the pit fire and Billy Ray did raku sculpture. I just made a dvd on obvara, raku,horse hair and ceramic saggar for teachers. I usually fire alone without anyone around. Maybe something can be arranged. It is simple but uses some nasty chemical. I only have one vapor respirator. This process requires nitric gloves and vapor respirator as safety gear. Marcia Link to comment Share on other sites More sharing options...
Marc McMillan Posted December 5, 2013 Report Share Posted December 5, 2013 ditto on the precautions. I wear a respirator whenever I am within 20' of the kiln. I've also taken to wearing full goggles and tyvec suite when I apply the ferric. Little droplets seem to get everywhere. I figure getting that stuff in the eyes should be avoided. Link to comment Share on other sites More sharing options...
PeterH Posted December 6, 2013 Report Share Posted December 6, 2013 Norm, Great idea to avoid ferric chloride when possible. Are you using ferrous or ferric phosphate, and what did you buy it as (e.g. slug killer). Regards, Peter Link to comment Share on other sites More sharing options...
Bob Coyle Posted December 6, 2013 Report Share Posted December 6, 2013 Here are pictures of my chemically treated bisqued pots that were post fired with only a propane torch. Though I am first to admit they are not anywhere near Marcia's'. They were treated with ferric chloride ( made by reacting clean steel wool with muriatic acid and evaporating til concentrated) and copper citrate ( made by reacting copper carbonate with citric acid.). The copper citrate has the advantage of not soaking in to the clay so much as copper sulphate. It gives a pretty green cast rather than just grey or black. Oh yeah.. I also am trying horse hair. with mixed results. Anyone know the sectet of how to keep it from rolling up into a single ball? Saggar... what saggar?... I don't need no stinking saggar! P.S Norm. Have you tried iorn oxalate... I have been thinking that might help the Fe stay on the surface so that you would not need so much to get a deep red. Link to comment Share on other sites More sharing options...
Workhouse Ceramics Program Posted December 6, 2013 Report Share Posted December 6, 2013 Hi Marcia, The Saggar pieces are beautiful...... If you would like to bounce ideas off someone- Paul Lyon a studio potter in Maryland has been experimenting quite a bit lately with foil saggar work. I atttached a pic . His contact info is: lyonclay@aol.com Dale Marhanka Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 6, 2013 Author Report Share Posted December 6, 2013 Nice work!. Thanks. There are quite a few foil saggar people around. Ken Turner did a great workshop at the PC conference in Minn. And Marc McMillan has shared several pieces recently in the members gallery. It is an interesting process involving some nasty chemicals. Thanks for sharing. Marcia Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 6, 2013 Author Report Share Posted December 6, 2013 Here are pictures of my chemically treated bisqued pots that were post fired with only a propane torch. Though I am first to admit they are not anywhere near Marcia's'. They were treated with ferric chloride ( made by reacting clean steel wool with muriatic acid and evaporating til concentrated) and copper citrate ( made by reacting copper carbonate with citric acid.). The copper citrate has the advantage of not soaking in to the clay so much as copper sulphate. It gives a pretty green cast rather than just grey or black. Oh yeah.. I also am trying horse hair. with mixed results. Anyone know the sectet of how to keep it from rolling up into a single ball? Saggar... what saggar?... I don't need no stinking saggar! P.S Norm. Have you tried iorn oxalate... I have been thinking that might help the Fe stay on the surface so that you would not need so much to get a deep red. Those are interesting. I used a torch on iron sulphate on some architectural pieces. It responds well to a torch. Are the others sulphates too? I used a torch to alter color of iron sulphate wash on terra cotta sculpture. It was really interesting. I did it outside for fresh air access.Marcia Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 6, 2013 Author Report Share Posted December 6, 2013 Norm, I like the idea of more PH neutral acids. Marcia Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 8, 2013 Author Report Share Posted December 8, 2013 ditto on the precautions. I wear a respirator whenever I am within 20' of the kiln. I've also taken to wearing full goggles and tyvec suite when I apply the ferric. Little droplets seem to get everywhere. I figure getting that stuff in the eyes should be avoided. I am not spraying these, I am applying with a sponge or sponge brush and working as neatly as possible. Still there are some stains on the formica. Good Idea about the goggles. Link to comment Share on other sites More sharing options...
Bob Coyle Posted December 8, 2013 Report Share Posted December 8, 2013 Those are interesting. I used a torch on iron sulphate on some architectural pieces. It responds well to a torch. Are the others sulphates too? Marcia Citric, tartaric, and oxalic acids are all some of the things I have used to dissolve copper carb to get the weak acid salt. As Norm mentioned, these are thicker, les soluble, solutions and hence tend to stay on the surface of a bisqued pot. so not as much is needed. I'd say it takes only about 1/3 the amount to get a good rich black compared with what I get using just copper sulfate. The copper citrate puts so much copper on the surface that You can actually see it flash to copper with the reducing flame of the torch. Sadly, it oxidizes again immediately I have used ferric ammonium chloride instead of straight ferric chloride, and it seems to give a weaker color. Nom's iron phosphate looks like the way to go I wonder could any of this stuff we have been talking about be used in conjunction with the Obvara technique you have perfected. If you could maybe spritz the pot with copper citrate and then Obvara it and get it into reduction it might be pretty interesting. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 8, 2013 Author Report Share Posted December 8, 2013 Interesting info Bob. Where does one begin to look for citric, tartaric and oxalic acids? I have been avoiding spritzing but these chemicals may not be as hazardous. I wouldn't say I have perfected Obvara but it is fascinating. I can try something with it in January. I will be away during the holidays visiting family. and friends. I'll let you know what happens. Marcia Link to comment Share on other sites More sharing options...
Bob Coyle Posted December 8, 2013 Report Share Posted December 8, 2013 Citric acid you can buy in many markets or health food stores. Tartaric acid is a little harder but chemical supply houses have it and probably e-bay. Oxalic acid you get at Home Depot. It is the only one that is toxic... but , since you are not going to eat it, and since it just burns up when flamed with no toxic fumes, there is no problem. Anyway keep it in mind next time you do your magic... Have fun on the holidays Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 9, 2013 Author Report Share Posted December 9, 2013 Citric acid you can buy in many markets or health food stores. Tartaric acid is a little harder but chemical supply houses have it and probably e-bay. Oxalic acid you get at Home Depot. It is the only one that is toxic... but , since you are not going to eat it, and since it just burns up when flamed with no toxic fumes, there is no problem. Anyway keep it in mind next time you do your magic... Have fun on the holidays Thanks, Bob. I'll look in the grocery stores. I have citrus skins that also do some things but not all that interesting yet. I need to understand what to do with them. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted January 27, 2014 Author Report Share Posted January 27, 2014 Here is my favorite from the recent batch of foil sagger pots. Link to comment Share on other sites More sharing options...
Benzine Posted January 27, 2014 Report Share Posted January 27, 2014 Excellent Marcia, what did you have in the sagger? Link to comment Share on other sites More sharing options...
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