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Rick Wise

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Everything posted by Rick Wise

  1. Although I am storing the clay in a large, sealed, plastic container that has a wet plaster bottom (a very moist environment) it remains too hard even after months of storage! II must be missing something. Related : While stored in the plastic container, is it better to open the bag or keep it closed with the rubber band ? (Sometimes I have been leaving it open on the theory that the environment in the plastic container is MORE moist than the clay.)
  2. Seems to me you do! I intend to go forth with this simplifying thought in my head: Functionally, a well-suspended glaze is a flocculated glaze, and a flocculated glaze is a well-suspended glaze. (Even though, as neilestrick points out above, its technically not "flocculated" unless the suspension has been achieved by the addition of a flocculent.)
  3. Someone more experienced than me should answer this -- but I think the gerstley gives it a nice smooth melt so that the surface texture is not rough.
  4. Mine end up too thin I think because of my misguided effort to get all the "height" I can from the given amount of clay. Leaving them thicker should not be a problem since I end up trimming them extensively anyway.
  5. So .... not to belabor it but -- if all the glaze ingredients (the clay, bentonite, and all the rest) are indeed suspended and staying suspended it would by definition be "flocculated". Right?
  6. I have a good feeling about this suggestion! Gonna turn over a new leaf and make my rims thicker. Thanks
  7. On a seemingly random basis, I have cups and mugs whose rims warp while drying from wet to leather hard. The handles have not been attached so that is not the culprit. I try to make sure that drying is "even" and not drafty. If I notice at just the right time I can sometimes "re-round" them but often they are too dry and will crack if I attempt to alter them back into shape. I would love to hear anyone's thoughts on what causes this, how to avoid, or how to correct when it does happen. (I've tried letting them dry with a dixie cup inserted into them flush to the rim. But then the cup shrinks onto the dixie cup and it difficult to remove)
  8. I often hear people say that they use bentonite or some other material so as to keep glaze ingredients "suspended" and to prevent "hard-panning". My question: Are the terms "flocculated" and "suspended" essentially synonyms in this context? For instance, if all of the ingredients in my glaze are well "suspended" is the glazeit then also well "flocculated"? Or is there some essential difference or distinction between these 2 terms.
  9. That makes a lotmore sense than what I was after. Thanks.
  10. Having laid out the problem like that in the above, it now seems a little clearer to me. I guess i need to measure out the colorant needed for a 10,000 gram batch (dry weight), and then add 1/100 of that amount to each cup? As in: Recipe calls for 2% colorant 10,000 gram batch needs 200 grams of colorant. each 100 gram cup gets 1/100 of 200 grams or 2 grams. ??? Right ???
  11. Bill Thanks. All very helpful. A "line blend" problem I keep encountering and that I cant seem to get comfortable with: OK. I have a 10,000 gram batch of the above recipe (but without the colorants) and i want to do a line blend. (Of course the 10,000 grams is the dry weight of the ingredients and i have added unknown amounts of water) I need to measure out small portions of the liquid glaze in which to do the line blends. For instance, 10 small cups each containing 100 grams of glaze. How do I then calculate how much colorant to put in each? If I say that this cup is 100/10,000ths of the total (i.e. 1/100th), I am ignoring the water weight aren't I? How do I calculate this colorant "add" number?
  12. Finally! See pic and recipe below. (Sorry but the photos would disappear when posted from my ipad)
  13. I would like to make a "reclaim bat", i.e. a tray on which I can lay wet clay/slip so that the water absorbs out of it for eventual re-use. Should I use pottery plaster or plaster of paris? And why?
  14. "In-glaze". That stumped me. Thankful for Wikipedia. Here it is for all of my fellow dummies: https://en.wikipedia.org/wiki/In-glaze_decoration
  15. I should have noted the context: electric Cone 6 firing in oxidation
  16. I've noticed some subtle differences in the finished glaze between the inside and the outside of pieces like cups and mugs. For instance, the outside of a mug will have pinholes but the inside surface does not. I am assuming that the inside of a cup will get hotter than the outside and that this explains the phenomenon. Thoughts?
  17. Would I be doing a lot of damage to my electric kiln if I applied some paper stencils to a piece and let them burn off in a glaze firing rather than remove them beforehand?
  18. Thanks Neil. I am always tempted to think that a higher fire temp will drive MORE water off thereby making the bisque MORE porous and absorbent. However, I guess the fact is that ALL of the water is already driven off at 06 and continuing to 04 just "shrinks the pores". Would that be a correct way of looking at it?
  19. I normally bisque to cone 06 and glaze to cone 6 (electric). Someone recently suggested that I try bisquing to 04 instead of 06 to reduce the chances of pinholing. Can someone explain what changes I might expect in the way the pieces react to glazing and firing? Will the higher temp makes them MORE absorbent? LESS absorbent? What considerations do I need to keep in mind?
  20. Good point Oldlady. Effective communication is HARD!
  21. I know that kilns are sometimes "slow cooled" to create or enhance certain desired effects such as crystal formation. I also know that "abrupt cooling" should be avoided because of the danger of thermal shock cracking. My question is: At what temperature are the effects of slow cooling no longer expected? Am I correct in thinking that at and below about 1000 F the only concern is with "abrupt cooling" and that any "slow cooling effects" have been achieved (or not)? Put another way, are all of the "slow cooling" effects seen at relatively high temperatures well above 1000 F? At 1000 F my only concern with cooling is avoiding thermal shock -- right?
  22. I post this as sort of a "public service" to other pottery semi-newbies like myself. I somehow never got the message that you can easily paint oxide (and mason stain) washes on top of glazes for a lot of added color or design. The videos below brought this to my attention and I am really excited about the results. It has opened up some new avenues for me. I defer to Richard McColl for a full description but it could not be easier: Just add some oxides (or mason stains), a little water, and maybe some gerstley borate as a flux -- and apply ON TOP of your glaze for great color and effects. Goes on great with a brush. Make it the consistency of ink. Hard to screw up. Some examples are at the bottom and here are the videos:
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