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tbaa

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  1. Yes, most things are available, but the quality is uncertain. And being new at this, I have no way of telling what it should be. I would like matte glazes. Yest, the original is matte, though the pieces near the flame were quite glossy. I quit trying reduction as the glazes werent working, and I figured getting the hang of kiln and the firing process should come first. (1st time i've fired this kiln with some sense of control....) so maybe I'll try reduction after I get my glazes set up. Everything came out great today - again a first! The Amaco glazes (i have a couple of jars) work well consistently. Indigo blue float for example. So I do think the materials have something to do with the results.
  2. How wonderful to wake up to so many replies. I will call my supplier today and get details on the feldspar.. I have 4 different frits - equivalents of Ferro 3195, 3134, (which I believe is a 'boron frit",) 3124 and 3110. These are sold under the manufacturer's 'code', and some of the ferro frits are grouped /lumped together as one. (Ferro 3110, and 4110 are sold as one. Ferro 3134, 4108, 4144 are grouped as one.) I have both 3134 and 3124 which are labeled as Calcium Borate frits, and have the same temperature references. I dont know what makes them different, but I have smaller quantities of these. I also have lead bisilicate which the glaze guy wanted, to demonstrate how well it melts. I have wollastonite, talc, whiting, gerstley borate, zinc oxide, dolomite, strontium carb, lithium carb, in varying quantities. I think these are all fluxes . A host of other materials - oxides, opacifiers etc - neph sye, ball clay, china clay, EPK/Kaolin and even 2 kilos of cornish stone. I fire a gas kiln. After about 6 glaze firings, I finally felt I had some sense of the workings of my kiln yesterday. Cone pack at the bottom melted before the cone pack on top. And cone 5 did not melt at the temperature it should have......or the temperature gauge is defective..... Neil, I will certainly test the recipe you suggest. And glazenerd, I will check with the supplier if Mahavir potash spar is available here. (You will be amazed at what India exports and what is available for local consumption.....) I had 20 kgs of Potash feldspar, which turned out to be the main defective ingredient - most of the glazes I was tested were coming out dry. Apparently it was for very high fired glazes, or completely defective. When the glaze guy made his first batch, they were all bad. Shocking for him, no surprise for me - and he would not look at the results of my material tests before mixing his recipes. I had to dispose of the potash spar, and have used only soda feldspar for my new experiments. Thank you all so much.
  3. thank you. Good start. I will look up silica/magnesium proportions and see if I find anything meaningful!
  4. Can someone help me resolve glaze problems please? Several firings and tests later, I am still unable to get a good base glaze. Yes, new at all this,. Besides working in a remote area in the mountains in India. Some of the materials have been a problem. I paid for a ceramicist specializing in glazes to come to help. After two weeks of work, I have one glaze base that works, but still needs to go to 1265C. NOT the cone 6 I wanted. I have about 8 base recipes that are of NO use to me . They all need to go to 1280C - Now that I know my potash feldspar was defective, I will try Nelsons Base etc all over again. But would love to have this one recipe work at ^6. Could anyone suggest how to adjust it?? (The minimum this glaze needs is 1250C - and can go to 1280+. so I am pretty sure i wont get the melt I need at 1222C. ) Ingredients are: Soda Feldspar 45; China Clay 20; Dolomite 20; Talc 5; Whiting 3; Titanium 5; Tin oxide 2. I get a nice slightly speckled grey. Some test tiles were more creamy than grey, but wares all fired as grey. Cobalt and red iron oxide have worked well. Copper has not. Any ideas of what other colorants to test with the above, or why copper didnt work ....? That is IF there is a way to make this a cone 6 recipe??? Sorry to sound so ignorant - but chemistry is a beyond my scope - Doing ma best - but mainly trial and error. I do NOT understand the what, how and why of the materials !! I LOVE my bisqued pieces.....
  5. oh fantastic! thanks so much.
  6. How long can glazed pieces be left before firing? days? months? I have some pieces I've glazed but as I am travelling, it may be a month before I can fire them. Also, as I do underglaze decoration and sgraffito I'd like to get some pieces ready, and simply have them ready to dip them in clear glaze before firing. Are the colors likely to be affected? I just read some amazing advice on how to use hairspray or spray-on starch to prevent smudging of underglazes, oxides etc. Can I then dip these items (protected with starch or hairspray) into my clear glaze would the hairspray / starch contaminate the glaze?? This seems like a 'no-brainer' as the oxides DO contaminate the glaze....and the hairspray / starch simply burns away in the firing....but as it seems too good to be true, I simply have to check. Despite a lot of advice from people like Marcia Selsor, glazenerd and others, I am still trying to make glazes that work. This involves a few days of getting things ready for the kiln. As I develop glazes that work, I'd like to have some things ready to fire, while I mix and test new recipes and combinations. Hence the question about how long glazed pieces can sit around before being fired. as always - many thanks in advance!
  7. thanks Min. this seems the way with ceramics!!! I am still working on getting ^6 glazes I like, so unlikely I will ruin any while experimenting. Thanks for the suggestion for heating the pots.
  8. Some of my cone 6 glazes have had poor results. I'd like to experiment by re-firing these pieces, using a low-fire glaze. Is this possible? And lustre glazes? what would work best over cone 6 glazes ? Any suggestions and guidance will be hugely appreciated!
  9. tbaa

    Teaching Ceramics to Adults

    I came here looking for possible instructors, but this is just to share my thoughts on why I think teaching skills are important. Good instruction takes away a lot of the uncertainty when you're learning. Many clay/pottery classes are very 'try your hand at throwing' ..... you'll get the hang of it. Easier said than done. Four years ago I committed to pottery and set up a studio at home. the clay was the first challenge. My experience with an instructor a few years ago, made a huge difference to my centering and throwing skills. Marc Mancuso, who I took some one on one classes with in Boston, was extremely helpful in explaining what needs to done to that lump of clay, where to apply pressure etc. I dont wrestle with the clay anymore. Then I got a lot of input about clay bodies etc here on CAD. Also very carefully considered and well articulated. Clay body issues resolved. My experience with a glazing workshop in India was dismal. I learned nothing - not about materials, not about how some of these interact, and nothing about firing. Marc was great with glazes as well, but the materials and conditions and fuel are all different here. I have books, I've been on line and gotten a lot of advice. From some very experienced people. All helpful, but the materials and conditions remained a problem. I finally found a ceramicist who is knowledgeable about the materials and their chemistry, and helped me develop my first base glazes. Explained some of the nuances of firing, and helped me test a batch of glazes. I have learnt a lot, and though I have yet to fire these new glazes, I am prepared to do it with more confidence. The biggest problem turned out to be one of the feldspars - I recently tried to set up a small course for beginner potters at my home in the Himalayas, and had to call it off. The instructor I found is a very talented ceramicist, but unorganized, and without any "lesson plan". I know pottery cant be a rigidly timed or instructed class, but yes, strong teaching skills are a good thing!
  10. Two firings and I am making progress, albeit slowly. While I am testing various base glazes, I found that Nelson's base from Marcia Selsor's handout works well. I tried all four colors as well, and Chcolate worked the best. A couple of questions: Black and granite were nearly the same. I will try the granite with less Iron Oxide. Black had some olive flecks, and granite was a darker version. I used iron oxide black in both recipes - should it have been red? While the flow/melt was good on all others, the teal came out dry. Any idea why that would happen??? Lastly, If I mix a large batch of the base, is it possible for me to mix colorants into smaller batches of the ready base glaze? I have a dry total of 100grams. add 80 - 100 grams of water, getting a total of 180-110. Any way I can add colorants to say every 180g of this? Too good to be possible???
  11. two firings, and its not as difficult as I thought it would be! Still, a LONG way to go, but the above advice helped. Thanks!
  12. O.K.! Well, enough wondering what to do I guess. will start with firing first thing tomorrow morning. Thank you all for your help, AND patience.
  13. My test tiles. Square ones fired in A Delhi studio where I went for a glaze course. The smaller ones below, fired in my test kiln. Clay from my own batch in both instances. Turquoise glaze is the lakeside studio recipe, mixed at the Delhi studio. two very different results. So thats what I'd like to keep working on - the firing schedule, and will see what the kiln's quirks are over time.
  14. John, Oh boy, your post shows now.... anyhow, .....
  15. J Baymore - i saw your note about primitive pottery, though it doesnt show here. Sent a reply but some glitch with checking if I was a robot or not.... Long reply with picture posted....but no idea where it went. Holey moley! So, here I go again: Thanks, I will look for the book. I am now trying to work out firing schedules. Mainly at what rate to increase temperature in my kiln. How many degrees over how much time - from whatever the loaded kiln reads at before I light it.
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