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Chris Throws Pots

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Everything posted by Chris Throws Pots

  1. Linda, Did the kiln ever shut off on its own? Or did you have to kill the breaker? I'm with Neil that it sounds like there there are issues with the relays, and glad to hear you're replacing these. I once had relays die in the "complete circuit" position. So rather than preventing any electricity from getting to the elements, they were constantly delivering power, even though the kiln's controller was showing IDLE. It was a pretty scary situation and the only way I could shut off power to the elements was to turn the kiln off at the breaker. Good Luck! Chris
  2. Stilts of all sizes: https://www.sheffield-pottery.com/category-s/112.htm The glaze will release from the metal (nichrome) prongs, but it will stick to the ceramic base of the stilts, just as it will the shelf. Make sure your pieces are balanced and only in contact with the prongs. As mentioned earlier in the thread, you'll likely end up with little sharp prong marks. You can easily grind these down with a Silicon Carbide Dremel Attachment or with slightly more effort using a Stilt Mark Grinding Stone.
  3. I would suggest using a tabletop wheel such as a Shimpo Aspire or Speedball Artista (or maybe even a Brent IE though this one may be a bit too tall) placed on an ADA compliant/wheelchair accessible table. You might have to build the table to make sure it's sturdy enough and has the dimensions you need, but I imagine it'd be far less expensive than purchasing Brent/AMACO #16. Perhaps there's someone in your studio community who uses a wheelchair who could help you design something.
  4. Hi AMI, I can't see the cracks you're referring to in the picture, but a typical cause of cracks developing in the glaze during cooling/after firing is crazing. Crazing is caused by improper fit between the glaze and the clay body. During the cooling, both the clay and glaze shrink. Crazing occurs when the glaze shrinks more than the clay body. Make sure your clay and glaze are both rated for maturity at the same cone. IE If you're using ^04 clay, use ^04 glaze; using ^6 clay, use ^6 glaze. If you're mixing your own glaze you could try to adjust the recipe for a better fit. If you're using a commercial glaze, maybe try a different product.
  5. Thanks all for the advice and alternative suggestions. I kind of figured the concrete idea was just too good to be true. I opted just to use the barrel I'd already purchased and will be making another 20kg batch of glaze in a month or so to top off the barrel when I go into full on production glazing mode for summer markets.
  6. I finally made the commitment to making a large batch of my standard white glaze in order to move beyond the size limitations of a 5 gallon bucket and the nuisance/mess of transferring glaze from said 5 gallon bucket to shallow bins for plates. I was hoping to find a 15 gallon bucket with an available bucket dolly, but no such bucket appears to be on the market. I ended up going with a standard 20 gallon Brute garbage barrel. I mixed up three 10kg batches of my glaze, which amounts to about 12 liquid gallons. It fills to just above the halfway line of the barrel (the barrel tapers out toward the top). In addition to sitting low in the bucket, there is an annoying trough around the perimeter of the barrel's floor where the barrel dolly locks into place from the underside. I anticipate this trough will make stirring up the glaze adequately a challenge. So I'd like to make the 20 gallon barrel act more like a 15 gallon barrel with a flat bottom. My idea is to pour concrete into the bottom of the barrel to fill the trough and raise the floor of the barrel up by a few inches. I've never worked with concrete before, so in doing some research I learned that it is porous. So my question is: Will the porosity of the concrete matter? Will the concrete absorb one or more of the glaze ingredients in higher concentration than others... will the presence of the concrete throw off the chemistry by trapping one ingredient disproportionately? Will the concrete break down over time? If it is not safe to have the glaze in direct contact with the concrete, my plan B is to cut sheet PVC to the exact shape and size of the concrete slab and seal it in the barrel on top of the concrete. Thoughts, recommendations, warnings and alternative ideas will be appreciated. PS I know the easiest answer is to make up another 10kg batch or two of the glaze, but it's and expensive recipe and I'm out of materials.
  7. dirtbabe, You don't currently have studio monitors, but could you? I run a community clay studio that averages about 45 monthly renters and 40 adult students per month, with Friday night drop-ins, afterschool programming through the local school system, and other random programming scattered in. We probably average 150 different individuals accessing the studio any given month. Getting everyone to pull their own weight and clean up after themselves is one of a list of constant challenges the studio faces. There have been lots of good suggestions so far in the thread about the specifics relating to this piece of equipment, that kind of clay, etc, but for my studio, the most important piece in keeping things clean, organized and functional is my team of Studio Assistants. Each of these individuals hosts the studio for a consistent, weekly 4 hour chunk of time when studio members come in to practice/produce. All studio access for renters and students is contained to open studio hours hosted by a Studio Assistant. There are about 30 open studio hours per week... some mornings, some afternoons, lots of weekend time and a couple of late night shifts. The Studio Assistant arrangement is a work trade. They give their time in exchange for a set of keys for 24 hour access (outside of classes), a a large shelf space, a discount on clay, and most importantly the learning opportunities. For each shift I assign the Studio Assistant tasks such as loading/unloading kilns, mixing glazes, pugging clay and cleaning/organizational projects. In addition to this assigned work, there is a closing checklist that Studio Assistants complete to make sure the studio is always left in good shape. Ultimately Studio Assistants are responsible for leaving the studio clean. Often times Studio Assistants have to remind renters and students to clean up after themselves... a "you missed a spot" kind of thing. The Studio Assistants who are less comfortable with confrontation end up cleaning up after renters and students... and quickly become much more comfortable with confrontation. Without the Studio Assistants our space would turn into a heap very quickly. I could cover the place in signs about studio procedures and expectations, but without someone monitoring the space the signs would be ignored... people like making messes, not cleaning them up. Oh... and prior to working in the studio, members must sign a form that spells out what they can expect of the studio and what the studio can expect of them. That way, if someone does blow off their responsibilities we have a signed agreement form them stating they'll follow the rules. Ultimately, if you can take on some studio monitors and limit the hours of studio access to times when the space is hosted by a monitor your studio will stay in much better shape.
  8. Hi All, For the last few months I've been experimenting with decals. With my HP laser printer I've been printing my own iron-rich decals and getting results I'm really happy with (picture below). The process is pretty straightforward, and so long as the ^6 glaze I'm putting decals on top of doesn't change with the additional firing, the results are predictable and aesthetically where I want them to be. But I'm working in only one color. As mentioned in other decal-focused posts, a ceramic printer that can print full color decals costs a few grand. And while there are commercial services available for printing decals, I'm more of a DIY kind of guy. So I'd like to start screenprinting my own decals using gold overglaze, cobalt, etc, and I'm curious if anyone can help shed some light on this process. I have a background in screenprinting, so I'm very comfortable withe the physical steps of the process. What I'm wondering about are the following: - The decal paper needs to be submerged in water to get the backing paper to release. Is there a substance I should mix in with my overglaze/cobalt oxide wash to make it so the image wont wash off the paper? - Should I be spraying a fixer over the images instead of/in addition to mixing a fixing agent into my "ink"? - Should the decals be applied face-down? The iron decals can be applied right-side-up, but I have a suspicion that printing things backward and applying the paper with the "ink" in direct contact with the ware will be more effective. - Any ratios, recipes, tricks or tips will be appreciated. Thanks, Chris
  9. Seasoned Warrior, I have the good fortune to be able to fire a wood burning kiln a few times a year. We make cone 10-12 in the span of a day. Like has been wisely mentioned previously in the thread, just because it's not anagama, it doesn't mean it's not legitimate woodfiring. The design of this kiln is called the Phoenix Kiln, named for the Phoenix Workshops of Dunbarton, NH in the late 70s. There's an old issue of the Studio Potter (Vol 7 No 2) that describes it, and it's also discussed in the book Wood-fired Ceramics: Contemporary Practices. It's a small spring arch cross draft that climbs quickly. The placement of the firebox beneath the ware chamber is key. As the flame travels beneath the ware chamber it heats the floor of this section, gaining ambient heat before the flame comes into direct contact with the ware. Also, unlike in an anagama or norigama, there is no struggling with the cool ground. The pots are up off the ground so the pots and chamber heat very evenly. We use rough ends from the lumber mill that we purchase by the bundle and cut down to the right lengths. We use about a three quarters of a cord to a cord and a quarter per firing depending on how long the wood's been drying, how tight the load is, etc. Admittedly there is not the level of ash buildup you'd see in a more traditional 2 or 3 or 4 day firing, so we also salt at cone 10 to supplement. We get great results. The kiln was built in southern Vermont about 10 or 12 years ago, and after being relocated a number of times via crane and flatbed truck, the kiln's owner had the genius/insane idea to put the kiln on a trailer. So for the last few years it has been on a 20' heavy duty trailer. The kiln and trailer weigh about 10 tons total. With about a week's notice (and a large enough truck to haul it) we can take down the flue, support the arch with a form and drive to somewhere new to set it back up to demo or workshop. It's an ordeal to move, but pretty straightforward. The last time we moved the kiln was to it's current home in Burlington, Vermont's south end where the kiln's owner and I run a weekend workshop a couple times a year. As you look to faster woodfiring methods, check out the Phoenix Kiln. It might be a good fit for what you're looking for. C
  10. Nicolesy, I run a community clay studio, and in this arena kiln wash is a must. The problem is that given the frequency of our firings, our shelves warp quickly. I'd like to flip our shelves every 2 months to combat the warping, but grinding off the kiln wash leaves them with less-than-flat surfaces. So essentially I'd be trading warping issues for surface craters. And if the shelves aren't ground down pre-flip, the kiln wash flakes, glaze drips, etc will fall into the pots below. I'm between a rock and a hard place, and end up dealing with warped shelves until it's bad enough I just need to buy new ones for the studio. I have a few shelves for my own personal use which I've skipped the kiln wash and have marked the sides A and B with iron oxide wash. I keep a log and alternate which side is fired facing up. When I get my own kiln, this is how I will fire. No kiln wash on the majority of shelves, alternating the sides to prevent wapring. I will keep a couple with wash for glaze tests, etc. If you know your glazes, keep a log of firing times to predict element health, and are mindful of your relays, my opinion is that it's worth the risks of firing sans wash. And I'd encourage flipping them regularly. Certainly all mishaps can't be avoided, but the more exact your practices can be (and it sounds like you have pretty exact practices) the better risk management you'll have. Good luck and congrats on the new kiln! C
  11. Like others have wisely mentioned already in the thread, function should dictate the form of the lid. The Val Cushing Handbook has a great section on lids. There are drawings of all sorts of different shapes, do's and don'ts, critical mistakes, tips, etc. When teaching lids to my students I'll share these pages and frame the discussion around function, then over the course of a couple weeks cover (no pun intended) 5 lids: - Basic Flange "The Hat" thrown upside down - Basic Gallery "The Bowl" thrown upside down - Flange + Gallery w/Inset Knob thrown rightside up - Flange + Gallery w/Attached Knob thrown upside down - The Russian Doll thrown as a closed form then trimmed gallery and flange So many lids, so little time. Someone also brought up firing lids atop their corresponding jar/teapot versus firing them separately. I'm all for firing lids along with their corresonding piece. Where the clay is going to experience change and movement as it shrinks, I want the set to experience all this change together as one piece. My two cents. C
  12. I'm in camp fluting. I have a mirror in my house (thrown with the intent to be a platter, but it cracked as it dried) that has a very similar look. I produced the marks with the rounded end of a Kemper trimming tool.
  13. TA, Congrats on your studio! In my opinion, the most important requirement for any studio is something that can't be bought. It's also something that can be very challenging to keep up with. It's a diligent committment to cleanliness and heath/safety practices. Especially in a private studio, where your decisions and actions only really impact yourself, it can be easy to get lazy about this stuff. Scrub and sand outside. Lift with your legs. Good posture at the wheel Replace your respirator cartridges when they're due. Vacuum often. No brooms. It's easy to say you'll follow the rules. It's harder to follow through and hold yourself accountable. It's something I struggle with and I can't imagine I'm alone. You're investing in your studio, take care of that investment by taking care of yourself. C
  14. As for the three tea bowls, I'm in camp throw-facet-stretch. I do not think they are carved. Michael Merritt AKA Try Pottery has a very quick YouTube video that shows a variation on the process that I find more effective that the Mark Peters way version. Check it out here: . The big difference is that in the Peters video from CAD, you go directly to a thick cone, then stretch to a bowl. In Merritt's version, you throw a thick bowl, then cone it back in before faceteing and stretching. Peters' end product is GORGEOUS, but in trying to learn this process I found initiating the bowl's curve from the start made for a more bowl-like form. I continually ended up with a nasty learner's curve/shoulder when going at it the way from the Peters video. There is another video I'd highly recommend that touches on this process. The Goldmark Gallery has a video focused on Lisa Hammond - her pots, process, studio, life, etc - that can be found here: . The faceting/stretching business starts at about 3:30, but the whole video is a great watch. Really all the Goldmark short film spotlights are great. Cheers, Chris
  15. High Bridge, Check the podcast out in the iTunes Store (free) by searching The Potters Cast, or by going directly to the source at www.ThePottersCast.com. Paul Blais is the host and has been doing a great job with this new program. I was really thrilled and honored to be invited to guest. Cheers, C
  16. Six months down. Wow. How are we doing? I've done well with some, not so well with others. But there's still another 6 months to go. Outside of the goals I established in January, I was invited to guest on "The Potters Cast" podcast. Episode 10 if anyone is interested.
  17. I don't have a great electrical understanding, but I can share this. When I suspect I have an aging or shot element, using my multimeter, and with the breaker turned off, I measure the resistance. Based on conversations with Skutt techs, I know that I am supposed to look for a resistance reading within 1.5 ohms PLUS or MINUS the the specs. Anything outside of that range is the cue to replace the element. By that logic, resistance value could increase as the element wears out.
  18. To determine compatibility with laser printers, look up the MSDS sheet for the toner cartridge the specific model uses. Some laser printers use polymers as the main pigment ingredient. These won't work. Others use iron, listed as ingredients beginning with the prefix "ferr." This what to look for. The HP I have uses 45% iron in the toner pigment. As I understand it the polymers, when melted, are the binder of the colourant to the paper in laser printers. Originally carbon was used as the colourant for black and this is still used by most laser printer manufacturers. However HP definitely uses iron oxide (also written as ferrous/ ferrous/ferrite) for their MONO laser printers. To add to this, the reason a colour laser is not suitable, is that the printer drum has to go to a higher temperature to melt the polymers used for the other colours. This higher heat melts the laser decal paper onto the drum thus rendering the printer useless. Regards Johanna Thanks for clarifying, Johanna. I suppose I made a bad assumption when reading the MSDS sheets for incompatible printers. The high percentage of polymers led me to infer that this was a pigment source. Do you know if the polymers can be embedded with iron-based substances? The MSDS sheets I read for Brother printers showed the polymer making up 80%+ of the total toner material and carbon as only 5%-10%. I am surprised that this low percentage of carbon would give saturated enough color for effective printing. But then I don't know how the carbon reacts with the polymer once the polymer melts. I'm curious if you know whether the polymers can hold iron (or other pigment) or if it is simply a vehicle for the carbon.
  19. To determine compatibility with laser printers, look up the MSDS sheet for the toner cartridge the specific model uses. Some laser printers use polymers as the main pigment ingredient. These won't work. Others use iron, listed as ingredients beginning with the prefix "ferr." This what to look for. The HP I have uses 45% iron in the toner pigment.
  20. For all interested about decals, both commercially printed and at-home laser printed, explore Justin Rothshank's website. His work often features decals, and his website has a full section dedicated to decal resources. http://rothshank.com/justins-work/decal-resources/ There is also a Ceramic Arts Daily DVD available that is hosted by Justin and focuses on the use of decals. Here's an excerpt from the DVD showing how to prep and apply full-wrap decal to a mug: http://mobile.ceramicartsdaily.org/bookstore/ceramic-decals-2/
  21. Kris, Here's a link to an old thread about stuck lids. There's a lot of comments within the posts about the use of wax with alumina hydrate. http://community.ceramicartsdaily.org/topic/5560-stuck-lids/?fromsearch=1 C
  22. I ask all our studio members and students to wash all wax-dedicated brushed with hot water and soap after every use. But inevitably they get gummed up over time. We just boil some water and soak the brushes until the water cools and they're good for another month or so.
  23. Thanks, Celia, The recipe isn't mine to give. Sorry! C
  24. I've had similar bloating issues with Laguna #65 and #90. It's interesting to hear that the presence of manganese can be a cause for bloating. At times I'll find a bag or two of the #90 that appears speckled with manganese, even though it's not supposed to be in there. It's almost as if the mixer or pugmill wasn't thoroughly cleaned after the batch before the #90 was mixed. If I see more bloating in this clay body I'll make note of whether it's (unexpectedly) speckled. At the studio where I work we often have tightly packed kilns full of thick-walled work made by youth. Surprisingly these were rarely the pieces which bloated. We'd see it in thinner, balanced, well-thrown pots... Maybe the kids' pots were so thick the bloats never made it to the surface. We'd been firing to ^07, and a bump to ^06 helped correct the issue. Our program is slow - I like to see 14:30ish - with a 4 hour hold at 200F and a 25 minute hold at peak (1800F).
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