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About Genboomxer

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  • Location
    Thousand Oaks, CA
  • Interests
    Pottery, brewing, gardening, cooking.

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  1. This soil is from the west San Fernando Valley in So CA. What can I infer from the result I go? No bloating or black coring evident in the samples. I'm guessing I will need to stick to low-fire, majolica or non-functional projects? Thanks again for the knowledge.
  2. Hello again Nerd! I finally got around to firing a sample of my project to ^6. In the attached photo I have 2 samples. Top sample is native soil (I call it CPM) mixed 50/50 with ^10 b-mix. I'm pleased with the results so far regarding texture and color. Shrinkage is ~12%. I also glazed a small mug made of the same 50/50 clay body with a home-mixed celadon (Britt Basic) and it turned out quite nice. I does appear to have crazed though. The bottom sample is the native by itself fired to ^6. Dark brown and glassy. It broke during firing. Probably during cool-down? It isn't brittle as I've tried to break it by hand and it's quite strong. I think this answers the iron / pyrite content question? Thanks again for your insights!
  3. Thank you for sharing! The more I see of NC the more I understand why it is such a hub for potters. Three different varieties of clay within a stone's throw? Amazing. And their work is elegant. P.S. I took a look at your website and I really like your work. I especially like the Distress Cetre mugs, and the motivation and humanity that inspired them.
  4. Thank you! I started this project about 5 months ago, but I've only recently had the time and means to fire and test at home.
  5. Thank you for the links! I looked for similar topics here but sometimes if you don't use the right key word it doesn't come up. I did drop a piece of the fired clay into vinegar and it only fizzed for a second, so I'm interpreting that to mean I'm good on lime distribution. I am working on more test tiles today, and buying more witness cones for the varying temps I plan to test at. I think analysis will also help in that I should be focusing on practicing with what I have rather than playing with a theory. But I love learning new things. So much appreciation for the wisdom and guidance!
  6. Testing makes a lot of sense. Do you have a suggested lab?
  7. I guess I'm not sure what you mean by "what type of clay it is". I'm guessing it's a type of high iron, terra cotta earthenware. The soil is from the west San Fernando Valley of Los Angeles, in the shadow of the sandstone bluffs where I grew up. I know the S. F. Mission made its roof and floor tiles, as well as some tableware and storage ware from locally sourced clay, so this keeps me hopeful it is viable with the right treatment. I assumed I would have to do extensive testing because I haven't found a lot of other folks doing it online, and I have a tendency to do weird things few people do for my own creatively nutty reasons. Commercially available clay is great, but I want to add a personal, unique twist to my work if I can. I wasn't sure I would get this far, so I'm excited to do the work. I purchased some ball clay (OM-4) and feldspars for mixing my own glazes (another new experience of experimentation) so I will start to play with those ingredients and see where I get. It would help to have a methodology for adding such materials in the right ratios. It's not a deal breaker if I can't make a stoneware out of it, but I do want a durable and versatile local clay body for functional wares. A ball mill is not a budget priority so I will just have to work around it. Although I have a desire to see if the nearby sandstone can be used as a glaze ingredient. I did find a report on the sandstone. It is composed of 54% granite; 45% feldspar, cemented with limonite (iron ore). So who knows I might eventually get a ball mill (maybe a large rock tumbler? ) for that and see what happens. I've been trying to decipher the survey maps myself. I've read several, but they're pretty general for the area; no actual analysis of the specific soil, just suitability for farming and erosion characteristics. "Sandy loam" is not helpful. Mineral content of the soil is still eluding me, but I hunt on. Edit: P.S. - Any insights regarding the 50/50 blend with ^10 B-Mix? Does this theoretically up the maturation temp? I have only found one other person who has done this, and fired it to ^6 with success, but they haven't done any more than that. Thanks, Dave
  8. Thanks for the link! Turns out I've done most of what is suggested. I will do vinegar eat tonight because I know there was a lime industry uphill from my source and this is part of the geological makeup of the region. I have found more information about the source material (sandstone) than I have on the actual soil. Any help for where to look for that is appreciated. I tested a bar of it and broke it in half. No carbon coring at all. I do not have a small test kiln per se, but I do have 2 kilns to work with, one ^6 electric. 3.3 cu ft, and an ancient 7 cu ft gas kiln that can easily handle up to ^12, so I'm set there. I am in the process of testing, but I'm really new to this and want to make sure I get all the info I can. Also, if someone has already gone down the same paths I'm on, maybe I don't have to do as much work. I want to explore all the possibilities with this wild clay. What can I do with earthenware? How can I make it a clay body that matures at ^6 and/or ^10? All the stuff. Thanks, Dave
  9. Hello Forum Folks, One of the current projects I'm working on, now that I've acquired a little skill and knowledge, is to make some functional pieces from native soil. This is something I've wanted to do since I was a kid playing in the fields where I grew up. I collected about 40 lbs of soil from an excavation site, slaked it into a slurry, and sieved it to ~40 mesh. I dried it out on a hardibacker board, wedged it up and let it sit for a week. I netted about 20 lbs of a VERY sandy and short clay body. I decided not to use or test it because of the sandy consistency. I slaked it again and sieved it through 80 mesh which removed about 5 more lbs of fine sand. Dried/wedged/waited a week as before. This resulted in 15 lbs of a still short, but significantly more plastic, smelly clay body of a very dark, grey/green/brown color. It dries to a light grey/green. I'm guesstimating a 35% - 40% clay content??? Given the geology of the area I expected a very iron rich content. There are a lot of gold speckles when viewed in the sunlight that leads me to think Pyrite is plentiful. Maybe mica? The soil is from an alluvial plain about a mile from sandstone formations that was used for agriculture before heavy development in the middle of the last century. I wedged up a couple of chunks to see how it would perform on the wheel. It gave little resistance and was remarkably soft and easy to throw. Like really thick peanut butter with sand in it. I decided I wasn't going to try and make anything too fine or thin because I was afraid of overworking it too quickly. It produced little slip and soaked up a lot of water. I kept what slip I had and let it dry completely. It is very hard to break and snaps apart without crumbling, if that means anything. The 2 items I made had excellent green strength. attaching a handle was an exercise in patience because of how short the clay turned out. I fully expected the handle to pop off in the bisque firing. I also made a 10cm test tile to check shrinkage. Dry shrink is ~6% or 7%. Next, I decided that I couldn't leave well enough alone. I combined equal parts ^10 B-Mix with the native clay, wedged it to homogeneity, and threw a small mug. This improved plasticity, was easier to throw, and demanded less water. It behaved like a sandy B-mix and was a lot easier to put a handle on. I then did a ^06 bisque load in my electric kiln. I was expecting havoc and woe when I opened the kiln, but was pleased with the results so far. The native clay body fired to a deep terra cotta color Pictures do not do it justice. The blended clay body is a light salmon-y color. The native has a bright ring when thumped; the blend a little less bright, even though it has thinner walls (prob. b/c of B-mix?) I have attached before and after photos for consideration. Next I need to determine a suitable final firing temp to glaze and mature my experiments. I also want to improve the workability and plasticity of the native clay body, but I'm not sure where to start. I've read various methods for doing this, but it's like brewing: ask 10 brewers a question and you get 12 different answers. I'm sure that combining with the B-Mix was a quick and dirty impulse fraught with peril, but I can't help thinking it is a viable way to go. What does this combination do in terms of glaze matching and maturation temp? I think the native clay is a bit more straight forward in that it is terra cotta, so there are probably easier options to choose and test. I'm thinking Spanish style of a white or red glaze (clear?). I also want to use some of the processed native soil to glaze with. I've seen it work on ^10 clay bodies, but not at ^6. Thanks in advance for the wisdom. Dave
  10. Oldlady - One of my other hobbies is beekeeping. Wasps are not on my "nice" list already, they serve no purpose other than to aggravate, so I'm glad they've left us both alone!
  11. Hi Forum Folks, So this happened today - I bought a used kiln this weekend and was very excited to get it up and running. It is a Cress FX23p, 20 yrs old, and the elements, bricks, etc. are in excellent condition. I loaded it up, plugged it in, followed the instructions and everything. The kiln sitter button would not engage. I repeated everything several times; nothing. Power was fine. Lights stayed on as long as I kept a finger on the button. Timer was turning. All settings correct, but the button still did not engage and stay put. I called Cress and was forwarded to their Tech Support voicemail. I left my number and a brief explanation of the problem. Then I went to the webs... came here to the forum but found no previous post on this problem. Fortunately I found my answer elsewhere and was able to get it up and running easily. Turns out I made a couple of mistakes: 1) I didn't plug the kiln in and try it before buying. That would have probably made me negotiate a lower price, or walked away, since I would have discovered the problem sooner. 2) I didn't consider that the kiln, although garage kept, had been sitting uncovered for a few years so that a significant layer of dust and dirt accumulated around the wiring and switches of the kiln sitter. Long-sh story short, I took the panel off and removed the muck. The problem was that dirt/dust accumulated between the kiln sitter panel and the weighted mechanism that holds the button in place during firing. Once cleaned and a couple of judicious squirts of WD-40 later, it is humming and heating like it should. Just wanted to post this for others in the community that are considering buying a used kiln. If any experts out there have more words of wisdom for me, please do not be shy. BTW - still waiting for the Cress tech to call me back. ;-) Peace.
  12. Hi Kiki, I'm a newbie too and I'm in the process of setting up my home studio. I am currently practicing (...and practicing, and practicing) making small functional pieces, i.e. mugs, bowls, tumblers, pitchers, etc. I acquired a very old and very manual 7cu. ft. gas kiln from a local potter who couldn't operate it any longer. The price, $0.00, was right, but I discovered that at my current level, 7 cu. ft. is a bit on the large side. I'm a little slow, and I don't have a lot of spare time yet to practice as much as I should, so it takes a while to get a full load together. Also the kiln is so manual that I have to constantly manipulate it to get the right heat/work/time ramp. I'm learning a lot about gas firing probably in the most difficult way, but I enjoy learning and using low-tech because it gets me closer to the process and makes me think (harder). Just this last weekend I bought a used Cress model FX23p electric kiln. It is half the volume and 1/3 the outer size of my gas kiln and a lot easier to load and operate. I'm in the process of a bisque firing as I type this! It was very lightly used and in excellent shape, and a good price at $600 because it included a lot of kiln furniture and extras that I can use for both kilns. The reason I bought a smaller, electric kiln is that I wanted more versatility. I already know what types of glazes and atmospheres I want to use. The manual kiln is fine, but it takes longer to fill and fire. I can use the electric for all my bisque as well as fire to ^6 for oxidation glazes. I want to use the gas kiln mostly for ^6 & ^10 reduction glaze firings. I have the best of both worlds (I think). Lucky for me I found good deals on both kilns so my studio budget for kilns so far with purchase, repairs/upgrades has only cost me about $800 (so far). I'm very handy and mechanically skilled so I do the upgrade/repair work myself. I was also lucky to have the correct wiring already in my garage studio so the electrical work was already done. You can pick up some really good deals on Craigslist for used kilns, but you need to decide the kind of work you will be doing. I don't necessarily recommend this for your or anyone else's situation, I'm just an equipment nerd who can't pass up a deal. ...and the wheel I use is an old Laguna kick wheel which was also a craigslist find for ~$300, so the most modern equipment in my studio right now is probably the 20yr old kiln! Sorry, I'm a bit verbose I know, but I guess it comes down to figuring out what it is you ultimately want to produce, and how much capacity you need to produce. You can buy and grow into a larger kiln if you determine you will be cranking out functional production ware for sale. You may also want to determine your costs of operation of one size over another. I have noticed that many of the potters I follow on YouTube have kilns in the 3.5 cu ft size and turn out a lot of ware frequently. Hulk and Igusten gave solid advice to consider. I find this forum and YouTube to be excellent resources too. Lots of inspiration and technical knowledge to be found. I'm close to L.A. too and there is a surprising dearth of pottery resources around after you've gone the Parks&Rec. / JC route. There are artist coops/studio complexes around, and they will likely have a studio or 2 giving classes on ceramics. The fees are a bit steep compared to the JC/Parks classes, but you can get great instruction from a local artist who knows the terrain. I recently contacted a local potters guild and I will be attending my first meeting next week in hopes that I will be able to network with like-minded, experienced folk and maybe get to shadow a few in their studios. Research, research, research. OK, nuff said! Best of luck to you! Forward!
  13. Don't believe everything you think.

  14. So here I am, back from the pottery trenches with more knowledge, bruises, burns, and experience! I got this old girl to fire up for a bisque load and it worked out better than I expected. I replaced all of the piping not associated with the burners, cleaned out the orifices and replaced the WC gauge. I figured out how to use the pilot ring to help light all the burners, and I engineered a separate pilot light assembly that keeps the Baso valve open. It's a bit of a dance to get the balance right, but once everything is warmed and going it is quite easy to make adjustments. It's very sensitive the slightest changes in gas pressure too. Candling is a challenge since there are 5 burners, and even at lowest pressure they heat the chamber very quickly. I just cracked the top open to keep it around 250* - 300*. She's a little uneven from top to bottom as evidenced from the reference cones. I estimate about a 1/2 cone cooler at the bottom shelf. I will definitely be experimenting with the flue more the next time to see if I can hit a better balance. I didn't pack it vey full either so there wasn't a lot of mass to hold/radiate heat. I invested in a digital pyrometer and a new K-type thermocouple too. I kept the t-couple in the bottom 90% of the time because I only have 2 choices and that seemed the more logical. Additionally, the kiln is really well insulated. I can stand next to it on a warm day and not be uncomfortable. I mean I can almost put my hand on the outer shell. It holds heat really well too, because 13 hours after I shut off the gas everything in there was still way too hot to touch. I had to slowly open the lid little by little to cool everything down to unload. At 7 cu ft it takes me a while to get enough time to make enough ware for a full packing. I'm retired now so I anticipate that to improve. Also, I'm looking into getting a used electric kiln about half the size to do most bisque and ^5/6 ox. glaze firings. I want to use the gas kiln mainly for ^5/6 & ^10 reduction glaze firings. Maybe it's overkill, but I think for the amount of ware I make, and the hassle it is to set up the gas kiln each time it may be worth it just for the bisque firings. I already have an outlet rated for the e-kiln I'm currently looking at. More questions of the experts - Where can I find a good guide for how to load my kiln efficiently? Or is there a general rule of thumb? I am getting ready to do some glaze firing with it for the first time, any wisdom or tips on that? I plan to do a few tests with different clay bodies and glazes, both ^5/6 o&r & ^10 r so I expect mixed results. One more question - the old manual says to place the bottom shelf min. of 6" from the floor, but that puts the shelf about 1" above the bottom peep hole, and makes witness cone placement out of sight and forces me to place the thermocouple below the bottom shelf. Is there a standard height for bottom shelves? I haven't seen anything on this topic. I want to thank all who posted on this all that time back. You all gave me great advice and thinks to think on. This is exciting and new and feels a bit dangerous too. I feel like a kid with new toys!
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