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Hulk

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  1. Like
    Hulk reacted to wens in Terra sigillata deflocculation from local clay   
    Agreed, but with it so thinned out I couldn't get a true specific gravity to plug into the formula - it was too close to 1. Next batch, I'll try not to thin it out too much. Appreciate all the info!
  2. Like
    Hulk reacted to Denice in Suggestions for pottery tool bag   
    A tool bag that mechanics use might be something to look into.   There are many different sizes and features,  I  have tool box trays in my studio,  you couldn't carry them but they are very handy and inexpensive.    Denice
  3. Like
    Hulk reacted to Mark C. in Potters who are to longer with us-Glaze recipes live on   
    So I am testing some new liner glazes today to look for one to replace my go to I have used for 40+ years. I opened my glaze book and found one TRJ emailed back in the day from this site, also wishing me a Merry Christmas . For those that do not recall him he was another professional full timer like me from Canada. After a few years of back and forth  emails we were going to meet at an upcoming NCECA but alas he got sick and passed away. His posts live on here just like mine will when I'm gone. He shared info freely as many do on this site. I mixed up his liner cone 10 reduction glaze  today and will test it in coming week. It was good today thinking about a man I never met and what may have been. Now I may be using his liner glaze on a zillon pots if I like it. Thanks  TOM akaTRJ
    On that note I did meet another Potter last week at a Crafts Fair in Saint Louis and we did a mug exchange . I was there twofold to visit with my wifes sister who moved 1 hour south of STL  last year. Also we drove south 3 hours to see the eclipse which was fabulous with clear skies our second one in  the past 7 years. It was a joy to meet another potter from this site and share stories and ideas.I had my  coffee in his copper red mug this morning.Its a small planet really.
  4. Like
    Hulk got a reaction from Bill Kielb in Im desperate   
    Didn't see anything in the news a few weeks ago; I'd missed this, "The EPA says the smells near the Reilly Tar & Chemical Co. Superfund site matched benzene, pyridines and ammonia." from Neighbors concerned over years of bad smell prompts action from EPA (wrtv.com)
    The article includes a photo of Tibbs Ave/Minnesota St intersection, which is... 105 miles away, perhaps not related.
    Best wishes for identifying the problem(s) asap.
  5. Like
    Hulk reacted to Bill Kielb in Im desperate   
    Copper is interesting and there are limits but most often found in an industrial setting when testing for heavy metals.. Sounds like you need a real environmental air test and lab analysis to figure this out ……… then figure out the source. Clay may or may not be a concern here so a real test with real quantities of constituents likely is the best way to know with reasonable certainty. For now, no exposure or very limited exposure until you can correct seems important. Adding cleaning chemicals, moisture etc… can amplify effects. I suggest get  a real test and lab analysis ……. on paper by an industrial hygienist or equivalent.
  6. Like
    Hulk reacted to twsincich in First Wood Fired Kiln Build, Problem Stalling   
    Thank you all for the kind words and support! Been a wonderful adventure so far and am excited to see where the road leads now that I have some bearings! Will keep you all posted on the next firing! 
     
  7. Like
    Hulk reacted to Denice in I’m in need of a water basin for my potters wheel   
    I have a Brent with a large splash pan,  I still get curls of clay on the floor when I trim.  I hung vinyl wallpaper around my wheel because I will splatter clay when throwing.   I actually love seeing the curls,  it means that I am  still able to work in my studio at the age of 71.   To me a part of being a potter is having a mess to clean up.   Today I am cleaning the studio so I can mix up glazes for testing and making a new mess.   Embrace the mess.     Denice
  8. Like
    Hulk got a reaction from Bill Kielb in How to use this kiln   
    I'm seeing Evenheat model 1210 described thus (where the volts, amps, and watts values line up):
    "The RM II 1210 is the ultimate personal ceramic studio design. The RM II 1210 is designed to fire china paints and clay materials up to 1800°F (982°C), cone 07 on a daily basis."
    Note, the 2280 value stamped on the depicted plate is labelled "watts"...
    ...looks like the low fire model there SierraRed18!
    The 1210B  Evenheat model, however, is 240v, 3120 watts, rated cone 10, 2350°F ("High Fire")
     
  9. Like
    Hulk reacted to LAR in Cone melted to metal setter arm   
    Thank you so much, new friends in this (new to me) community.  I appreciate so much your help and time, and expertise.  In reading various posts yesterday, I learned that cones are basically glaze (glass), so I gently broke off the melted cone.   I'm wiser than yesterday, thanks to my mistakes and all of your shared knowledge.  Next step for me is glazing.   If you don't mind, I'll check in with y'all as I learn.
    Again,
    thanks for explaining and advising me regarding what happened, and ways to improve my outcomes.
    This is a fun adventure for me.   Here's my first haul.   Beads, glazed beads firing rack, wall art slabs, (maybe to be used as stamps on canvas too), glazed pendant firing hangers, and sculptures by grandkids, etc.  Fingers crossed.
    LAR in CA 

  10. Like
    Hulk reacted to LeeU in QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?   
    I use Peggy Heer’s orIgInal Spooze, which is, essentially, 1/3 ea. clay, vinegar & corn syrup. Sorry-too tired to find the recipe, but it's online.  I use this when I want to join or mend something or fill in a crack  on dried greenware. It works great for my purpose. (which is not production/retail/professional). It has never failed! 
  11. Like
    Hulk got a reaction from LeeU in The Pottery of Sound   
    I do like water.
    A few years ago I tried for a fountain, driven by a small pond pump.
    Credit the FDR Memorial (Washington, DC) fountains, in part, for positive inspiration, a neighbor's drop-in pool kit for negative inspiration.
    The former, a variety of water sounds, each fountain different, each pleasing; the latter, a solid stream, not so pleasing.
    I wanted a soft drip, hence, the water flows over the inverted cone shape, falls a short distance (.8 to 1.2") to the tower base, then another inch or so to the reservoir, producing a gentle gurgling murmur.
    The pump is concealed between the base and tower, wrapped in foam to dull the humming.

  12. Like
    Hulk got a reaction from pottery007 in The Pottery of Sound   
    I do like water.
    A few years ago I tried for a fountain, driven by a small pond pump.
    Credit the FDR Memorial (Washington, DC) fountains, in part, for positive inspiration, a neighbor's drop-in pool kit for negative inspiration.
    The former, a variety of water sounds, each fountain different, each pleasing; the latter, a solid stream, not so pleasing.
    I wanted a soft drip, hence, the water flows over the inverted cone shape, falls a short distance (.8 to 1.2") to the tower base, then another inch or so to the reservoir, producing a gentle gurgling murmur.
    The pump is concealed between the base and tower, wrapped in foam to dull the humming.

  13. Like
    Hulk reacted to Mark C. in QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?   
    I use the slip from my hands throwing medium and larger forms. I keep in in tall plastic open container with a piece of light plastic over it. If it gets thick we add  a splash of vinegar. Sometimes no vinegar for months.  Thgis slip is always teh same body we are working with and water is not added. I also collect from splash pan if needed quickly, gthge thicker stuff .Never bothered about magic-I learned ceramnics before those concepts where born and never needed them so never thought about doing them later. Now I will add we handle thousands of mugs every year in porcelain and getting the handles on same day is the norm with the clay all the same moisture content. Handles,  on then cover with loose light plastic sheets that night uncover and let dry. If any small cracks appear I use a thin wood stick to rub them out while loading them in bisque kiln. (pro tip I leaned from another potter in the 80s) then they never show up again. Also if you do this while loading that saves handling them another time which is all about time saving which is what am all about with clay.
  14. Like
    Hulk reacted to pottery007 in The Pottery of Sound   
    Oh my gosh you guys! I was not expecting anyone to be responding to my questions because I thought it would easily get lost. Opened the forum today and I'm seeing all of these comments and learning so much from you all. Thank you so much for taking the time and commenting over here. I've been carrying out a lot of my research based off of Instagram and Pinterest looking through works by various artists and how that connects to their audience. It has started to get very interesting. I will be sharing all that I've learned as things progress forward. It is going to take me some time to read through all of the comments and since it is late here in Melbourne and I'm sleepy I can't comprehend everything, haha! But I shall be back here tomorrow! Thank you so much once again! I'm so very happy! Thank youuu!!
  15. Like
    Hulk reacted to Jarman Porcelain in Warped rims on my porcelain sculptures   
    I made a body of sculptures out of porcelain paper clay that were somewhat similar. I was using a translucent cone 6 porcelain and firing to cone 8. To prevent them from collapsing in the kiln I made a rudimentary saggar that I placed them into, then filled the void, as well as the piece, with silica sand. This went about half way up the side, I stabilized the "handles" at the top by rolling up some fiber blanket into a tight tube and running through each loop. For more complex shapes you can use kanthal wire to bind rolls to each other. Make the saggar (maybe armature is a better word?) out of cone 10 raku clay or fire clay so you can reuse them forever. 

    Good luck, those pieces look great already.

  16. Like
    Hulk got a reaction from LeeU in QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?   
    What
    Attachments (in my experience, err, limited experience), almost always one piece is damper than the other.
    The drier bit, I'll pick up half a drop of water with my finger and wet the attachment point - not enough to run, enough to impart a sheen that dissipates as the water is absorbed - add another half drop, as required (credit Ingleton potter Dick Unsworth's teapot process video).
    The wetter bit, I might dampen just enough to bring up a sheen, then score it in two crosses* (like UK flag), pile on a blob of slip, score the pre-dampened landing spot (in no particular pattern), dampen it a touch more, then get to attaching. I don't mind if it slides a bit at first, for it tightens up considerably as the moisture dissipates into the surrounding (dryer) clay.
    For shallow angles, like the top portion of a mug handle's lower attachment, I roll a small coil (2-3 mm, if that), cut to length, wet it, set it aside. After all ends are attached, I'm brushing a bit of slip in there, placing the coil, then smooshing it in. The edge of a loop tool fits in there. A damp brush can help. I don't remember where I saw this, perhaps a Pinnell video clip.
    ...now I do the same on the top attachment as well.


    Why
    Variations on what we were shown in Wheel I class.
    There was talk of vinegar and "Magic Water" - I was curious; what is magic water**, how does it work, what are advantages & drawbacks?
    I was curious, but not enough to dig into it, for my attachments were much less a problem (at that time) than so many other things!
    Adding the tiny coil, well, the radius can be achieved by other means, shaping the end, for example (credit Simon Leach video clip).
     
    * The slip squeezes out along the score lines.
    Nah, but that was the idea, which is now habit.
    **Here's an article and recipe:
    Magic Water (ceramicartsnetwork.org)
     
  17. Like
    Hulk reacted to Roberta12 in QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?   
    Magic water. That is how I was trained.  But I think I may try @Min idea of magic water with slip for my porcelain handles.  
  18. Like
    Hulk reacted to Min in QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?   
    I've been using slip made with magic water and my dry claybody for years. I use a smooth white claybody and fire to cone 6. I think it makes a difference which claybody is being used, some are far more prone to handles etc popping off than others.
    Magic water helps as the slip made with it is stickier than made with just water, it dries harder than plain slip and during the firing the extra sodium in the slip helps flux the slip a little more than plain slip making a stronger join post firing.
  19. Like
    Hulk got a reaction from Roberta12 in QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?   
    What
    Attachments (in my experience, err, limited experience), almost always one piece is damper than the other.
    The drier bit, I'll pick up half a drop of water with my finger and wet the attachment point - not enough to run, enough to impart a sheen that dissipates as the water is absorbed - add another half drop, as required (credit Ingleton potter Dick Unsworth's teapot process video).
    The wetter bit, I might dampen just enough to bring up a sheen, then score it in two crosses* (like UK flag), pile on a blob of slip, score the pre-dampened landing spot (in no particular pattern), dampen it a touch more, then get to attaching. I don't mind if it slides a bit at first, for it tightens up considerably as the moisture dissipates into the surrounding (dryer) clay.
    For shallow angles, like the top portion of a mug handle's lower attachment, I roll a small coil (2-3 mm, if that), cut to length, wet it, set it aside. After all ends are attached, I'm brushing a bit of slip in there, placing the coil, then smooshing it in. The edge of a loop tool fits in there. A damp brush can help. I don't remember where I saw this, perhaps a Pinnell video clip.
    ...now I do the same on the top attachment as well.


    Why
    Variations on what we were shown in Wheel I class.
    There was talk of vinegar and "Magic Water" - I was curious; what is magic water**, how does it work, what are advantages & drawbacks?
    I was curious, but not enough to dig into it, for my attachments were much less a problem (at that time) than so many other things!
    Adding the tiny coil, well, the radius can be achieved by other means, shaping the end, for example (credit Simon Leach video clip).
     
    * The slip squeezes out along the score lines.
    Nah, but that was the idea, which is now habit.
    **Here's an article and recipe:
    Magic Water (ceramicartsnetwork.org)
     
  20. Like
    Hulk reacted to twsincich in First Wood Fired Kiln Build, Problem Stalling   
    The pieces came out really well, especially since this was only my 4th time firing a kiln and first time slip casting anything! I made a cone 10 stoneware body and a cone 10 porcelain body to cast with and made 16 new cone 10 glazes to test out as well. So I definitely risked all my marbles that I'd be able to get the kiln up to temp! Everything in the very front split apart which I am assuming because it was directly near the burning wood and sometimes the wood did hit the pieces. So that is an easy lesson to fix. I'm thinking maybe some kind of bag wall of bricks would help? Ideally I would probably want the firebox and grate to be much lower to prevent this but without a huge rebuild I'm hoping I can figure something simpler out. Everything behind those fired wonderfully! 
     

     
    and some glaze testers 

     
  21. Like
    Hulk reacted to twsincich in First Wood Fired Kiln Build, Problem Stalling   
    As for the firing itself, I started much earlier than previous firings to give myself plenty of time and options to be patient and learn the kiln. After blowing up so many pieces being in a rush last time I let everything dry for a few days after finishing glazing and let it all candle with a heat lamp in the kiln for another day. Started the fire at 10am and wanted to hold it under 200 deg F for at least 2 hrs to make sure everything was as dry as it was going to get. Then I slowly starting to increase the temp until I hit around 500 deg F and then followed my usual climb rate of about 150 deg every half hour. No particular reason for 150/half hour but my first fire followed that and it seems to work. This was all done by simply using little cedar shake strips burning in the air intakes. After i hit 500 I started to put a piece of my cut 2x3x14" pine pieces onto the fire grate and would used splits pieces of those to stoke the air intakes. This rhythm of putting the full piece on the grate and then using split pieces in the air intakes seemed to work well to regulate the climb and get the wood to burn all the way down efficiently. Once I got to around 1800 deg F I started putting the single pieces onto the grate and there was a sufficient coal bed to burn the wood without stoking the air intakes with split pieces. After about 2000 deg F the climb started to slow down and I started to test different damper, air intake stoke and wood addition ratios. I learned that keeping the air intakes clear and allowing the coal bed to burn down allowed the wood to burn quicker. (I'm assuming because it was hot enough and more air intake) I also realized that instead of using full 2x3x14" pieces, if i split them into 3 or 4 pieces and added them onto the fire grate more often they burned quicker and the temp climbed easily. I was easily able to get to 2394 deg F (but NOT 2400 haha and I used a lot of wood and time to try to get there) At top temp I closed the chimney damper all the way and bricked up the kiln. I am fairly confident I can get it up to temp quicker and more efficiently than this time, with less wood now that I have gotten familiar with the kilns habits. 
     

     

  22. Like
    Hulk reacted to twsincich in First Wood Fired Kiln Build, Problem Stalling   
    @Kelly in AK @Russ @neilestrick @Biglou13 @C.Banks
     
    Hello to all who have posted help, just wanted to give an update since my most recent kiln firing with your suggested modifications. Thank you again SO MUCH for your kind words, advice and encouragement! 
    I am happy to report that I believe the firing went very well! I was able to fire the kiln up to a top temperature of 2394 deg F and the cone 10 on my cone packs in the front and back were completely bent. I think I may have even gotten to cone 11 in the very front but do not have cones for 11 so more of a guess. Started the fire at 10am and bricked up the kiln and closed the chimney damper all the way at 12:30 am for a total fire time of 14.5 hrs, which I am very happy with.
    What took so long? Well, I thought if I learned slip casting I could fill the kiln up quicker for another firing to test the modifications but of course that took a few months longer that planned. 
    The modifications I made were:
    1- Enlarged the exit flue to almost double the size it once was. Drilled small holes along the line I wanted to cut and then used progressively larger bits until the block fell right down. Not very pretty but perfectly functional and my major concern was cracking the pieces of brick left, so, success there. 



     
    2- Rebuilt the fire grate with 1 1/4" rebar and T bar steel that I picked up from the local junkyard. Little slump in the front (I'll add a support brick in the middle next time) Worked great as a cheap, replaceable fire grate that raised the wood up about 5 inches from where it was last time and opened up the coal pit area under it significantly. I could tell when I was firing that the coals superheated the wood, which burned better and faster and I only cleared out the coal bed minimally this time whereas the previous firings I would have to constantly rake out the coals once I hit 1900 deg F and would end the firing with a large pile of coals on the ground after. 


    How many firings will it last? I don't know but easily and cheaply replaceable. 
    3- Opened up the air intake space in the kiln door to allow more air in. As the coals seamed to burn down better and faster and the kiln seemed to draw well the entire firing, this seemed to help a lot in connection with the raised fire grate. 

     
    4- Insulated the chimney more up to the damper. I didn't have as many soft bricks as I thought so I just used a mix of hard and soft for this firing with some simple fireclay/sand mortar to see if it worked before I did anything more substantial. (I have to drive 3 hours to Portland for firebricks/clay/most things I need) Seemed to help! There was always a strong pull in the kiln and flames shooting up when I would stoke. 



  23. Like
    Hulk reacted to Beccap in Chrome & Zinc - toxic?   
    Yes I think when I started using 1% chrome I didn’t realise the dangers associated with it, and then looked it up and read the type that potters use is not the super scary harmful one. My over thinking brain has maybe thought in the presence of zinc, if chrome turns brown - is that chemically altering it to something that is toxic? And I can’t see it because there is also cobalt & rio so the colour change is not there? I think I am possibly overthinking the combination of zinc and the use of chromium oxide….

  24. Like
    Hulk reacted to Dick White in Chrome & Zinc - toxic?   
    As others have already noted, neither zinc oxide nor chrome oxide used in reasonable amounts in a stable glaze are toxic. A different issue arises when both are used together in the same glaze - ugliness abounds. Chrome is supposed to be green when in a glaze that does not contain tin. A combination with tin in the right amounts creates a variety of pinks and reds. Zinc with chrome, however, turns assorted shades of brown, when copious amounts are used. It won't hurt you, but you probably don't want to look at it. Perhaps your glaze recipe doesn't have enough for the adverse color reactions.
  25. Like
    Hulk reacted to Min in Chrome & Zinc - toxic?   
    Let's not throw the baby out with the bathwater here. The form of chrome used makes all the difference in the world in regards to toxicity.
    Potters use chrome oxide, it is insoluble in water and gets bound in the glaze matrix in a balance glaze. It is volatile in the kiln so it can cause a pink blush on tin white glazes. Wear gloves if you get contact dermatitis with it. (it's a good idea to wear gloves whenever handling raw materials and glaze slurries to avoid skin reactions)
    We do not use the exceedingly dangerous hexavalent chromium in ceramics. Iron chromate is toxic, stay away from using it.
    Zinc oxide fumes from kiln firing shouldn't be breathed in, zinc can become volatile above around 850C/1560F and like all the materials we use in glazes practice good studio hygiene and wear a respirator while handling dry materials. In a glaze it isn't a problem. 
    Chrome + tin pinks and reds are perfectly safe, whether in a stain or from the oxides.
     
     
     
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