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enbarro

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  1. Like
    enbarro reacted to Min in Why is glaze blue   
    I think the titania is combining with the iron in your clay and you have a very pale rutile blue. Also think your kiln was probably reducing. I've never had cobalt fuming.
  2. Like
    enbarro reacted to Min in Slop bucket clay seems a little bit "short."   
    I can't really see drying out new clay just to slake it down, and wouldn't want the dust from pulverizing it. If you do want to add unused clay, and can't get it powdered, I would just use it straight from the box and mix it with your wet scrap in the pugger, run it through a couple times to get it blended together and try it. (try bending a coil around your finger, clay shouldn't crack) If it's still not plastic enough I would leave it for a couple weeks and see if it's improved. If it's still short I would add more fresh unused clay and try again. 
  3. Like
    enbarro reacted to Chris Throws Pots in Slop bucket clay seems a little bit "short."   
    Our supplier (Vermont Ceramic Supply) doesn't stock the dry clay mix either, but they order it from Laguna for us whenever we need it. I'd ask your supplier... my guess is that it'll be an easy request to fulfill.
  4. Like
    enbarro got a reaction from hershey8 in Slop bucket clay seems a little bit "short."   
    Sometimes I've noticed the recycled clay being short, I use it for small pots...
    The local supplier doesn't sell the dry clay mix. 
    Would the short clay cause cracking problems with small 4"x 4"  terracota slabs?
    Thanks
     
     
  5. Like
    enbarro reacted to Min in Slop bucket clay seems a little bit "short."   
    +1 for this. The throwing water plus the slip/slop in the splashpan contains the fines. Since the smaller the clay particles the more plastic the clay is by adding the fines back to the clay it will help with restoring the plasticity to the clay. If you don't have enough throwing slip/splashpan slop to fix a short body you can add some ball clay, won't take much. (or blunged bentonite or macaloid if you are using porcelain) If your pugger has a vacuum that helps get the water in=between the clay particles to wet the small (plastic) particles, if not then pugging the clay on the wet side and letting it sit for a couple weeks will help also.
  6. Like
    enbarro reacted to neilestrick in Slop bucket clay seems a little bit "short."   
    Every time you work clay, fine particles are washed away in the throwing water. If that water isn't added back into the slop, the fine particles are missing. As  Min said, those are the particles that add plasticity. But you're also losing other ingredients, too, like the fluxes and silica. After you've reclaimed the slop a couple times, you've really got a clay body that is different than the original and may not fire to vitrification any more. The best way to deal with recycling is to make sure all the throwing water and slop in the splash pan goes into the slop buckets as well. If you need to add dry material, it's best to add a dry mix of the clay body you're using. Just adding ball clay can mess things up over time. Most clay manufacturers will sell dry mixes of their clay bodies.
    When I was the tech for A.R.T. Clay, I would regularly get phone calls from schools whose clay stopped working for them, usually in the way of glazes shivering off the white earthenware. They were pugging the reclaim with straight ball clay, and after a few rounds the body was all messed up, with too much clay and not enough talc. Their only solution was to start over with new clay, since we didn't know how much of anything was actually in the body anymore. So they would buy new moist clay, and a few bags of dry mix for recycling.
  7. Like
    enbarro reacted to Fred Sweet in Zircopax in earthenware underglazes   
    Vivk-
    Go to  priscillahollingsworth.com. Once on her home page follow this route: Home, info, extras
    The low fire glaze pdf resides there.
    Regards,
    Fred
  8. Like
    enbarro got a reaction from Rae Reich in Zircopax in earthenware underglazes   
    Yes, zircopax can be used to make white glazes. The problem might be it giving a different kind of white, if the white stain sold where you live uses Titanium or Tin Oxide as an opacifier instead of zirconium silicate.
    Some people feel the Zirconium white is too bright/harsh, you can use half Zircopax, half Tin oxide and or add small amounts of Titanium Oxide or light rutile to tone it down. 
    I think you are firing to cone 5? Not sure how much you’d need to add, because I use cone 03 terracotta clay. Some recipes call for up to 20% of zircopax. I use about 12-15% (but usually 10% is enough) when looking for a solid white and since my glazes are balanced never get pinholes. But according this old link it seems that my experience holds true at cone 5/6.
    http://www.potters.org/subject21453.htm
    Pinholes could be caused by different things (zircopax has never given me much trouble). The Recipe, how you mix it, how you bisque and what type of clay can also factor in:
    https://digitalfire.com/4sight/glossary/glossary_pinholing.html
    https://digitalfire.com/4sight/troubleshooting/ceramic_troubleshooting_glaze_pinholes_pitting.html
    Peeling is cause by the clay and glaze having different expansion % .
    https://digitalfire.com/4sight/education/understanding_thermal_expansion_in_ceramic_glazes_198.html
    https://digitalfire.com/4sight/troubleshooting/ceramic_troubleshooting_glaze_crazing.html
    https://digitalfire.com/4sight/education/adjusting_glaze_expansion_by_calculation_to_solve_shivering_199.html
    That website also has recipes…
    You could try doing a 3 part line blend. Adding Zircopax starting with 5% up to 10%, and then add 2 to  3% of frit and/or subtracting  2 to 3% kaolin at a time if you get pinholes. 
    Probably bentonite is not needed, because the recipe you listed is very high in clay content … you could try adding 1% if needed…
    https://digitalfire.com/4sight/material/bentonite_106.html
    Good Luck!
     
  9. Like
    enbarro reacted to neilestrick in glazing in red and black   
    You could probably get something close by doing a marbling technique with underglazes, and covering it with a nice thick clear glaze.
  10. Like
    enbarro got a reaction from CarlCravens in On The Subject Of Low Fire (Cone 04) Glazes, Is It Possible To Make A Floating Blue In This Firing Range? The Only Ones I Have Seen Have Been Cone 5-   
    Hi, floating blue is a rather special glaze... many factors going on at once... still, many cool floating-like effects can be achieved at lowfire.
    Digitalfire has an article on variagated glazes you might enjoy reading.
     
    At low fire temperatures layering seems to be the key... extending the firing/cooling time can help.
     
    A high boron glaze (using for example frits 3124,3134, 3195, gillespie borate, etc...) with titanium dioxide (around 5%) or rutile is a good starting point. A wash, well more like a glaze saturated with rutile/TiO2, applied thinly over other glazes can also do the trick. Applying over dark opaque glazes/slips can help. Bone ash is another interesting material.
     
    Adding small to tiny amounts of iron, copper, chromium, manganese, burnt umber can help you get a toned down blue or to get different colors.
     
    Stains are also worth a try...
     
     
    Chappelle's book has leaded glaze recipes that when layered create a variagated effect. I stay away from lead, but some people are ok with using it...
     
    I don't know if zinc oxide has the same effect at cone 04-03, because I haven't tried it...
     
    Also, please keep in mind that not every nice looking glaze is foodsafe.
  11. Like
    enbarro got a reaction from Biglou13 in Ultrox Superpax Zircopax-Plus, How To Choose?   
    Hi,
    Anyone knows if ultrox is still in production? Or if Superpax and Zircopax plus are the same thing? How do they all compare?
     
    My local store is out of Zircopax plus, so I need to order it... Uspigments doesn't sell it. They sell Zircopax which I thought was out of production. Ultrox is cheaper which is good, but I'm not sure if its still being made either.
     
    I rather stick to materials that are going to be available in the future and minimize glaze testing.
     
    Any help advice will be greatly appreciated.
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