glazenerd Posted August 26, 2017 Author Report Share Posted August 26, 2017 While throwing this test cylinder, pull enough extra clay to the top; in order to form the catcher. This cylinder would be inverted on your wheel; with the catcher on top when you finish throwing. You can make them tall and narrow, or wide and short: whatever fits your kiln. As you get your recipe dialed in, get the peak temperature correct, and the flux levels correct: you will find little to no glaze in the catcher. Nerd Link to comment Share on other sites More sharing options...
Babs Posted August 26, 2017 Report Share Posted August 26, 2017 Smiling wryly here, be sure you don't end up, down that burrow, knowing everything about nothing or nothing about everything!ðŸ˜ðŸ˜ðŸ˜ Link to comment Share on other sites More sharing options...
glazenerd Posted August 27, 2017 Author Report Share Posted August 27, 2017 "Posted Today, 06:42 PM "be sure you don't end up, down that burrow, knowing everything about nothing or nothing about everything! " Babs: I woke up about six months ago with exactly those thoughts. " I know a lot about clay and crystalline chemistry, and yet I know nothing." Link to comment Share on other sites More sharing options...
Babs Posted August 27, 2017 Report Share Posted August 27, 2017 It's like soil science. Chemistry tick Then ,b. Me there's the soil, temp, weather, etc etc etc so back to "local" knowledge and there are no absolutes esp when humans are involved . But it is fun, or at least not boring. And humbling when set against the amazingly beautiful pots made by the ancients and the "peasant potters", my term there. Pres is now trying to replicate his new baby 😊 Link to comment Share on other sites More sharing options...
Guest JBaymore Posted August 27, 2017 Report Share Posted August 27, 2017 ...........knowing everything about nothing or nothing about everything! THAT is when the real journey in your field finally begins. You are ready to begin to understand. best, ....................john Link to comment Share on other sites More sharing options...
Babs Posted August 27, 2017 Report Share Posted August 27, 2017 Yeh! Knowing that you don't know when perhaps you thought you did! Someone said to me recently, "you're not Still reading about this stuff....." Guess I'll never shut the books, no boredom here. And my memory is getting drifty.....sometimes I see a tiny little bit very clearly...then something else changes Link to comment Share on other sites More sharing options...
glazenerd Posted December 8, 2017 Author Report Share Posted December 8, 2017 For DW mainly, and others who fire crystalline. cone 5 crystalline ( peak 2225f) total holds(3.5 hours) largest crystal 3" DW: ten years ago I began to question how much of a roll clay played in crystal development. Six years ago I started doing clay research, one year ago I started developing porcelain specifically for crystalline. Pulled this final test out this morning. Looks rather cone 10'ish to me, even though it is cone 5. PR-2 porcelain. ( and no it is not for sale, nor is this an advertisement.) think I can stop researching now the chips on the rim are from my very poor trimming skills..still learning. Link to comment Share on other sites More sharing options...
glazenerd Posted December 8, 2017 Author Report Share Posted December 8, 2017 PDAs.. Notice the empty catcher? Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted December 8, 2017 Report Share Posted December 8, 2017 Tom, well done! I am encouraged to see that someone else believes that it is possible to make good crystalline glaze application without the glaze running off the pot! LT Link to comment Share on other sites More sharing options...
Dick White Posted December 8, 2017 Report Share Posted December 8, 2017 OMG, ASDF, or whatever initials the kids use these days to say that's awesome! Have you tested the body with other glaze formulations, e.g., different frit combinations, additions of alkaline earth fluxes, and, just as important, variations of colorant? Link to comment Share on other sites More sharing options...
glazenerd Posted December 8, 2017 Author Report Share Posted December 8, 2017 TY LT. Have long felt crystalline could go places, most thought not possible. DW: frit 3110. 50% A25 silica. 22% XL 500 ZNO. 25% TiO2. 0.05 % nerd suspender. 4 %. Lithium carb. 2.5%. Nerd no run 0.50% fairly simple/ run of the mill crystalline recipe. DW: will be testing most all the variables over the coming months. Mixed up 200 lbs. nerd Link to comment Share on other sites More sharing options...
glazenerd Posted December 8, 2017 Author Report Share Posted December 8, 2017 DW: side note- calculator says 6.58 COE( I think it's higher. Not a single graze line ( so far) Will have Ron Roy run it on his dilameter next spring. Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted December 13, 2017 Report Share Posted December 13, 2017 0.5% nerd no run what is small yet mighty? Link to comment Share on other sites More sharing options...
glazenerd Posted December 14, 2017 Author Report Share Posted December 14, 2017 Joel: a mixture of minerals that I process and chemically reduce to increase potency. Most crystalliers use alumina hydrate, which on this side of the pond is rather impure and rather ineffective. Imo nerd Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted December 15, 2017 Report Share Posted December 15, 2017 So is it something just under Aluminium, got to be somewhere similar, maybe. Link to comment Share on other sites More sharing options...
glazenerd Posted December 16, 2017 Author Report Share Posted December 16, 2017 Joel: always viewed crystalline on two planes: the first being it is an ionic bond. (magnetic bond)That said, it also means I believe that the clay body can promote or inhibit crystal growth. The second being amphoretic oxide: which I have not been able to find any supporting data at 2200 (1200C) temps and up. Although crystalline glaze is the only one I know of that can eat threw a 3" brick in a single firing. So I tend to do my experimenting along these two variables. as a side note, the piece above was fired on the low ramp cycle: still producing large crystals. Next spring I will fire some on the high ramp cycles; which will likely produce crystals in the 4-6" range...although I must say I am very curious to see what molybdenum will do on this clay. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted December 16, 2017 Report Share Posted December 16, 2017 clean up your trimming skills. That is a beauty! Link to comment Share on other sites More sharing options...
Fusioniz Posted November 19, 2018 Report Share Posted November 19, 2018 Hello, amateur artist here, may I know what is the portion of water to add to the reciepe? Link to comment Share on other sites More sharing options...
glazenerd Posted November 19, 2018 Author Report Share Posted November 19, 2018 Fusion: there has never been a value or ratio for water. You will find a wide variance from potter to potter. the rule(s) of thumb are: 1. Mix to a heavy cream consistency. You can thin it down, and simply apply more coats if needed. 2. You will need to add 2-4% bentonite ( add dry) to help with suspension and slow drying. Wetting bisq helps. the high % of zinc/frit in the recipe creates rapid drying of the glaze (almost on brush contact) so adjust water until you get comfortable with application. It will crack, do not try to fix it: nature of the beast. As long as it does not flake off- cook it! Sieving is almost mandatory with this glaze: frit likes to ball up. Application of glaze is more relative than the amount of water. This glaze will flow: ALOT! So application is thinner at the bottom, and heavy at the top of the piece. As a point of reference: 2 coats on the bottom 1/4 to 1/3. 3 coats on the middle to the upper 1/3. 4 coats on the upper third. If you thin it down from a heavy cream then add one coat per section. Dipping does not work well with this glaze. on page one there is a link showing Adam making and attaching catchers. It is normal for roughly 1/3 of the glaze to run off the pot. i can post a link showing application techniques if that will help. (DW might have one already?) there is a steep learning curve with this glaze- give yourself room to make mistakes. You can spot impatient crystalliers anywhere- they are bald! Tom EDIT: apply piece to catcher before glazing. The less it is handled after glazing- the better. Link to comment Share on other sites More sharing options...
Dick White Posted November 19, 2018 Report Share Posted November 19, 2018 I will add to Tom's second sentence - there is a wide variance from potter to potter for many aspects of the tumble down this particular rabbit hole. I don't use bentonite as a suspension agent, I use a mix of CMC gum in the water - for suspension, as a brushing agent, and to harden the surface of the glaze as I add more coats. The CMC gum mix is about the consistency of heavy cream, and I mix the glaze slurry to the consistency of honey or well-stirred Greek yogurt. And yes, sieving is imperative. I mix my crystalline glazes in small batches in quart mason jars using an old blender. Hamilton Beach and Oster blender jugs screw onto their respective blade/base with the same thread size as a common mason canning jar. Waring has a different thread size so you can't use a Waring blender; Hamilton Beach or Oster only. Also get a cheap plastic funnel for canning to aid in getting the glaze materials into the jar (the bottom of the funnel fits exactly in the top of the jar). dw Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted November 19, 2018 Report Share Posted November 19, 2018 Many solid-water slurries have a maximum volume percentage of about 60 percent solids. Based on that "rule of thumb" in the solid/water slurry engineering domain, and my experience with slurries both inside and outside of the studio potter discipline I use the following procedure: for glazes using clay, crushed rocks (feldspar, limestone, quartz, etc), crushed glass (aka frits), and colorants as major ingredients : I start with an amount of water that is 60 of the weight of the solids and additives being used. In other words if the solids is 1000 grams total, I use 600 grams of water. If the slurry is too stiff, I will carefully add additional water to meet the consistency needed for the application. When the glaze has been tested and declared successful, the amount of water as a percent of the dry solids is added to the recipe. I have not needed more than 70 % wt. water for the glazes I use. Most of my glaze application is dipping or pouring. More water may be needed for spraying. The procedure works for me . LT Link to comment Share on other sites More sharing options...
glazenerd Posted November 19, 2018 Author Report Share Posted November 19, 2018 Fusion: your question compelled me to a search. Peter Issley (deceased) from the UK wrote a book of crystalline glaze; as did Diane Creber of Canada. Neither of these two address an exact water addition other than "heavy cream" or " double cream." (UK ) i took a minute to test LT's recommendation: 60% water results in a peanut butter consistency. Crystalline glaze breaks all the fundamental rules of glaze: including water. Using 75% water creates a creamy slurry suitable for single fire application where water absorption is much less than bisq. For bisq, 80% water is a good starting point. That said: the suspender I use holds more water than bentonite without gelling. DW uses CMC, which will require a different water level. I know several who use 10% ball clay as suspenders: which require a different water content. Yellow zinc, white zinc, and calcined zinc all hold water differently. Hence the variables. Most crystalliers have become accustomed to " eyeing" to their preferred consistency. Start with the 60% addition mentioned by LT; then add 10% at a time until it hits a cream consistency you are comfortable working with. The suspender you chose will play a role in that level. More importantly: application of glaze as mentioned above. Secondly is application rate: vertical pieces- 0.65 to 0.75 grams per square inch of surface. Flat work: tile, low profile plates- 0.45 grams per square inch. ( application rates are not discussed in books either.) The rim of the plate receives more, and the bottom less: it will flow from the rim to the bottom when it melts. T Link to comment Share on other sites More sharing options...
cdudley Posted November 4, 2019 Report Share Posted November 4, 2019 This is all so helpful and I'm so grateful for this forum and the FREE information you are sharing with the community. THANK YOU. After reading about how the key with crystalline is precision, I feel like I already know the answer to this. But before I decide I can't try it in my current situation: Is there any way to create a firing schedule that will grow crystals using a witness cones and a kiln sitter? That's all I'm working with at the moment. Link to comment Share on other sites More sharing options...
glazenerd Posted November 5, 2019 Author Report Share Posted November 5, 2019 CD: thank you and your welcome. Let me qualify my response by saying: I have not personally fired crystalline in a manual kiln. That said: I know many who have and still do. In the many lengthy conversations I have had with manual firers', it requires constant monitoring during the crystal growth ramp holds, Firing schedules which includes ramping down from peak (cone 6) to growth ramps (cone 04ish) requires keeping a careful kiln log of switch settings, length of time, and kiln chamber "color." Firing manually is not impossible, but it is about as tough as manual firings can get. I can certainly reach out to those who still do for helpful insights, although it might take awhile to get a response. One of our forum members fired crystals manually back in 1973 with good success: perhaps she will chime in. Tom Link to comment Share on other sites More sharing options...
Dick White Posted November 5, 2019 Report Share Posted November 5, 2019 When I first became interested in crystalline glazes (in a school setting where we had digitally controlled kilns) I had only a manual kiln in my home studio. Fortunately my kiln had "infinite switches" that can be dialed up and down as needed rather than single or H/M/L click switches. The infinite switches are critical to be able to tweak the heat input to exactly match heat losses so as to maintain your predetermined temperatures during the crystal growing period. You will also need an external pyrometer and thermocouple (poke the thermocouple through a peephole and pack the space with some ceramic fiber, or drill an appropriate size hole specifically for the thermocouple). As Tom just noted, you must monitor this every few minutes and tweak the switches as neededto be sure the temperature stays where you want it. Finally, manual kilns have kiln sitters which will drop and shut off the kiln due to the heatwork from the extended holds. When the sitter drops, just lift it, push the white button to restart the kiln, and gently rest the weight back down so it sits at a slight angle without triggering the shutoff switch inside the sitter case. It can be done, but it's a lot of tedium. Link to comment Share on other sites More sharing options...
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