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  1. bypassing the bisque step?

    I've read that 8% bentonite added to the glaze can help with once-fired. I also remember something about glazes not running as much if once-fired. Also, test test test! Do test tiles and test bowls and such. That way you can figure out what glazes work best, modified.
  2. Cone 6 bisque what cone for glaze?

    For re-glazing I'll heat up the piece to around 300ish, and then 'boil on the glaze', but as my professor says. This would apply to this as well, but be sure to use tongs! I've successfully rescued pots before re-glazing, and and I'm sure that it would help with this. You may be able to go with a lower temp, you could set your kiln to reach 300 degrees, and and test how well the glaze adheres at the milestone numbers, like 100 150 and so on. Good luck!
  3. Pit firing

    One of my traits is that I don't mind asking odd questions that betray my ignorance. But – Briefly, as in the last twenty minutes, I've been looking at pit fired pots. I know that the pit fired pot isn't useable or water tight because it isn't covered with a glaze. BUT – could you: Bisque, Pit fire, and then High fire with a glaze? Could you keep the same fun colors that you get with the pit fire in a high fire, or would those things burn off?
  4. Glaze and clay exploration

    I'm kicking myself because I left the photo of the metallic glaze test at home. However, I did upload the photos of the 'new' Midori glaze. Now it's looking like a green celadon, before the re-design it looked like a crackling green glass. 'New' Midori 'old' Midori My plan is to do a line blend between the two, as the simplification that my professor did greatly changed the look... I don't mind the new look, but I'd like to see what happens in the blends. I have a feeling that through the line blends I'll start to get a feel about controlling the crackle. Midori old I've re-distributed everything to add up to 100%. Custer 18.2Flint 16EPK 16.8Crimson 4.6Gersley Borate 3.6Bentonite 1Whiting 7.4Neph Sy 8.2Volcanic Ash 13Mag Carb 3.2 TJR, after the glaze tests I've found a version of that metallic glaze that I like – I'll start calling it Iron #5 for now. (It was the fifth out of sixteen tests.) It has the red, but it also has a nice black accent that shows up on bumpy areas. I'll edit the photo in later, but for now here is the recipe. IRON #5EPK 4.4Bone Ash 11Talc 8.8Flint 22Custer 18F-4 27Spodumene 8.8 Iron was removed, and Red Iron will be added in 1% intervals as suggested. I'll also try the other colorants. I'll have to make taller test tiles, as the glaze runs. That's ok, as I also want to design functional wear that will suit the glaze. It's nice that Christmas is coming up... but I may go crazy, as I won't have access to 'the lab' and the wheel!
  5. silica carbide and lava glazes

    Ok, so I did a few test glazes @ cone 10 with a cratering slip. It didn't do anything, as a slip or a glaze... in any of the tests. This particular example was dipped in slip that had the SC, bisqued, and then glazed. I have a feeling that we had the wrong material, though. I'll find out the next time I'm at school. Ceramics by avaviel, on Flickr
  6. silica carbide and lava glazes

    My teacher obtained it from an industrial type place... something to do with glass. I'm doing some tests now. We're doing them as an addition to the slip – not the glaze. He recommended an addition of around 6%. In the tests, they range from 2% to 12%. I also did mixes with other glazes, to see what happens. edit: I found a link to a rock tumbler website, http://rocktumbler.com/grit.shtml They have the type that we used, the coarsest grit.
  7. Glaze and clay exploration

    Ah, it was my professor who modified this recipe based another one. I've really liked working with it, when I made a smaller batch. In the future, I'll formulate a porcelain based on this website: Formulating a Porcelain by DigitalFire I ALSO found that I don't hate stoneware as I previously thought. I sifted the sand and grog from it, and really liked it without that extra stuff. Having your glaze total 100 gives you a good grasp of percentages at a glance if you go to compare one with other glazes. It also makes for easy testing on colorants. Marcia Ah, that's a good point. I'm reading a book right now called The Ceramic Spectrum by Robin Hopper, but I'm not quite to that part yet. The next kiln fire I'll do some colorant tests.
  8. Glaze and clay exploration

    Thanks for the help! With the metallic glaze, I'm aiming to have a gun metal type feel, as I've noticed they transmit much less heat when on cups. For this test, I did something like a quad-axial, and the variable was the EPK. In the future, I'll give your test a try when I've seen the results of this cone 10 kiln. I need to start doing tests that vary a majority of the ingredients. Does it really matter if a glaze adds up to 100? Right now my thought is that it does not matter for internal testing, just making tests where the ingredients are 'parts', and the 'part' is one gram. (10 parts of x is 10 grams of x.) Then, when the glaze is finalized, make it into percents. I'm also testing amounts of Silica carbonate in slips/glazes to produce cratering. I think at some point I'd like to formulate a soft cratering gun metal glaze. Some day I'll be able to intuitively change glazes! I look forward to knowing the materials that much. I'll post the results of the glaze testing when the kiln cools.
  9. I hope this is ok: I'd like to make a thread about my own searches in glaze and clay formulating. The idea is that this would be a helpful resource, based on what I've read and the help I've recieved from my art teachers (ceramics or not – for example, my printmaking teacher is quite wise in areas that touch on clay.) I encourage anyone to comment about the stuff I post here. I'll most likely edit this top post as time goes on to add glazes, clay mixes, edit for content, edit for format, and add photos of the glazes. ____________________________________ Porcelain, cone 10. Tile#4* 24 EPK 16 OM4 Ball Clay 20 Silica (Flint) 18 Custer 22 *When I first mixed this, it was Diamond. For the main thing, my teacher suggested I get Tile#4. ____________________________________ I've decided that I absolutely love porcelain, and that throwing with it is wonderful. I've read a bit on formulating a porcelain clay here. Based upon a formulia I found online, and my teacher's insight, here is the clay that I'll be making next semester. I'm going to age it too; I'll be buying it as I'm able and will add some vinegar and other aging agents. If you guys have any thoughts on how this mix will be this next semester, I'm eagerly awaiting! If I can make helpful changes before I start, that will be nice. I may mix and age a portion of the Tile#4 in case I want to make any adjustments: Then I can add the dry materials with a new ratio. ____________________________________ Midori(N), cone 10 (Japanese for green) Custer 24 Silica (Flint) 19 Wollastonite 17 EPK 19 Crimson 5 Gersley Borate 4 Volcanic Ash 12 Mag Carb 4.5 Ceramics by avaviel, on Flickr ____________________________________ This is a glaze that is like a green clear, it crazes. This is the new formula that my teacher came up with, he rearranged a few things and made it shorter. (He described it as rearanging the parts of the glaze, consolidating the fluxes and glass makers.) I'll post a photo of the glaze bowl that this is on, I think I can live with the crazing. Typically, crazing have the cracks going in many directions... but on one of my bowls with a flat edge about a centimeter across, the cracks are about a cintemeter apart, all facing to the center. It's rather stunning: and I can say that because it wasn't my conscious choice to have it to do that! This is also the glaze that taught me that making glazes is really fun. ____________________________________ Metal Glaze Test, cone whatever... but I'll do it in 10. EPK 4 Bone Ash 10 Talc 8 Iron Oxide 10 Silica (Flint) 20 Feldspar!!!!!!!11111!!1eleveny: 48 ____________________________________ Here is the joke, regarding the feldspar: I saw this glaze in an old magazine. (I'll get the edition number later.) I showed it to him: It was a glaze for a predominately iron matte glaze. He read through the ingredients, saying that they made clear sense until he got to the feldspar. Which feldspar was the question. To that end: Let the glaze testing commence! In our art dept's clay area, we have four feldspars: Custer, F-4 (Soda), Sopdome, and Neph Sy. The idea is to mix the glaze around 300 grams four times, each with the full percent of the separate feldspars that we have in stock. Then, do a bunch of glaze tests to try and find something that we like. (We're not trying to duplicate the magazine, that would be futile and silly.) So there will be a bunch of test tiles with C+S+NS and so on. Interesting links: This is an older post about Lucy Rei's glazes. I plan to look up the magazine and post the results of the tests. Hopefully they have some of her cratering glazes. http://ceramicartsda...ucy-rei-glazes/ Hey, look. Iron! http://ceramicartsda...hnofileiron.pdf
  10. fractured porcelain in bisque

    I read a quote today, "If art isn't functional, bad pots are art*" or something to that effect. In this case, I'd love to see it glazed, even though it cracked. The fracture is quite beautiful. *Not to say I fully agree, the article was pointing out the disagreement between 'artists' and 'craftsmen', and how those distinctions can be superficial. But, I'm digressing from the thread...
  11. glazing and firing greenware

    Don't worry about taking a class as much! That is, unless you have time. You can learn just as much outside of a class by reading books and such. The point of school isn't a piece of paper saying you graduated, but the people you meet who have the same goals. (Don't mention that to certain professors and administrators, they believe that paper is the only goal one should have in life!) Historically, Lucie Rie was a potter who fired glazed greenware. In her studio, she kept a pilot light lit at all times. This would dry out the work in her studio. (You could maybe invest in a dehumidifier, if safety is an issue. Or, you could chance an uncontrolled studio-kiln fire!) She sometimes brushed on the glaze... while spinning it on a wheel! I'd wonder if it would be best to bush on glaze when the work isn't bone dry, and then let it dry. This way, you could apply the glaze while it already has a little moisture still making the piece strong. But that's just my personal wonderings. Really, you just need to use care that you don't break the greenwear while you glaze it. Personally, I see myself brushing the outside of bowls after pouring glaze on the inside.
  12. According to the art professor: a tablespoon of Epson salt will help keep the glaze from settling too much.
  13. glazing and firing greenware

    I talked to my professor about this very topic tonight! He suggested that if you fire with a gas kiln, to whatever cone (6 to whatever) that you 'candle' the kiln overnight. You turn on the pilot light, and then that will dry out the work if it isn't dry already. Also, you can dip your work, just use care and don't use tongs. Those were his words, but they do make sense.
  14. This is advice that comes from working around jewelers, and using both heat guns and torches: Keep it moving and even. Fluid back and fourth movements, evenly heating whatever you're heating. Ignoring the protests of my ceramics professor, I've started using porcelain. It's wonderful to work with, and the heat gun makes it even better. I've kept pots that I knew were goners because of the heat gun.
  15. Crater/rough glaze

    I love wood fire glazes! However, that isn't quite the style I want. I think I made a misnomer when I said Japanese tea cup, I'm referring to a few tea cups I own. I'll post a few links at the bottom of this post to similar things, and at some point I'll take a photo of the particular cup. The style may be described as a metallic matte? A plan matte glaze is something I'd avoid (the reasoning being that I'd rather color the clay or use a slip for a plain matte.) I'll be using porcelain exclusively for the time being (I'm in love with the stuff!) I just found out that I'm in love with ceramics, so forgive me if I go all over with my thoughts! I want to learn as much as I can about the chemicals so I can make the glazes do what I need/want them too. The one on the right: http://www.freeforms...ia/DSC_0118.jpg http://img0.etsystat...939884_6fu7.jpg Lastly, all of this has a simple goal: To be able to make a tea cup that does not need a handle, and isn't piping hot to the touch when just-boiled water is placed in the cup. I can tell this will be a life long adventure.