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perkolator

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Posts posted by perkolator

  1. For shelves I usually start with hand tools -- cold chisel/hammer/silicon carbide rub-brick.  

    Bad drips that eat into furniture I use a 4" angle grinder with a diamond-core grinder head -- I used to use a silicon carbide masonry head but the diamond-core head works amazingly well in comparison.

  2. Anyone looking for a good stick blender, I finally found one.  Waring Pro WSB33 commercial grade at only $80 on Amazon.  Went through 3x Cuisinart stick blenders, they all failed at the connection where the shaft detaches for cleaning  (plastic parts inside).  Anyways, this one does not come apart, steel guts inside and haven't been able to kill it yet :) Follow up with small Talisman test sieve.

    Larger batches using a drill with paint mixer head (do Jiffy mixers really do that much better???) and follow up with Talisman crank sieve.

    Rarely do dry mixing of glaze, it's always inside a lidded container if I do - like an old casting sip gallon  container or 5gal bucket with lid.

  3. FYI, Placer High School in Auburn CA is hiring a new Art Faculty to take over Ceramics. 

    Job just got posted this week:   https://www.edjoin.org/Home/JobPosting/1016332

    They want someone good, someone who knows ceramics and who will help continue inspiring and attracting students to their awesome art department - so pass this along to anyone you know who's looking.

    The classroom is already setup - lots of nice butcher block work tables, an elevated wheel throwing area for their electric wheels, attached kiln room with a brand new Skutt oval and another 1227, outdoor kiln yard setup with clay storage, de-airing pugmill, a small gas kiln that works and a larger gas kiln that was acquired years ago but never hooked up (looks barely used, but needs work on burner system IMO).  It's a pretty nice setup for a HS compared to other studios I've seen. 

  4. Wondering if anyone can please share their source for thicker nichrome or kanthal wire and rods?  Thick as in anywhere from say 8-16 gauge thickness (~3mm-1.5mm), not the thin stuff.

    Want to make some custom kiln furniture such as stilts and bead racks, etc.  The nichrome at all the local places is too thin for our application, like 20ga or thinner.  They do carry the normal 1/8" bead rack rods, but they add up $ quickly when sold a la carte.

    Some of the thicker rolls of wire I'm finding are about 12ga at about $1.75/ft

    For something like 9ga I'm seeing  about $4/ft

     

    Can anyone comment on using kanthal vs nichrome for suspending things in kilns?  I'm reading kanthal is slightly stronger, but can transfer iron to clay (I could just coat it with ITC-100 to resolve that?)

  5. For a project like this I'm thinking you need a slip/engobe that has a much higher than normal tensile strength or to cast it thicker - otherwise it's super fragile like you're experiencing, like look at it wrong and it's going to break, lol.

    The problem with trying to "layer" your material and gain thickness is that you now lose all the detail you were trying to capture -- such as the texture of fabric, yarn, sponge in this case, etc.  The key is to have a very fine particle size and allow it lots of time to wick up into the material you're trying to impregnate with slip.

    Ceramics tensile strength is simply very very low compared to the incredible compression strength it has and is effected by many factors.  To really refine this project I'd imagine you'll have lots of testing to do :D  Some basic examples I can think of that effect this:  particle density/porosity/particle size, vitrification level/sintering, crystalline structure/matrix/mullite development

  6. I can't think of anything either that resembles glaze and is a cold surface other than paint.  Closest thing I could suggest is silicone ( and possibly clear epoxy resin)  

    There are silicone casting products that are rated food-safe - an example would be Smooth-On "SORTA-Clear", which is a translucent silicone rubber (I think you can tint/color it too?)

    Not sure about the epoxy resin products.  I'd assume fine for cold items, but not for warm items.  Silicone is good up to at least 400+*F, you can stick it in the oven for baking or pour molten sugar in them for candy, etc.

  7. Have you tried firing it even hotter than ^6? Like up to ^7 even though it's a ^6 clay?  IMO it's worth a test (use a waste tray/shelf underneath just in case)

     

    You mention you "can't see any crazing"....to a molecule of water or a tiny bacteria, a teeny tiny fissure in the glaze is like the grand canyon, of course it will make it's way through!

    If your glaze is crazed, the glaze and clay body do not fit one another, their coefficient of expansion is too dissimilar.  This is only part of your problem, the other seems to be lack of vitrification in the clay itself.  For those experiencing seeping on thicker forms - this is because the thicker it is, the more heat work it requires to penetrate the core of that clay mass and bring it to full maturity - which is why reducing thickness via trimming the foot resolved the problem.

     

    To test if your clay is vitrified: fire object and then weigh it.  soak in water for 24hrs, dry it off as best you can and then weigh it again.  calculate % of absorption from the difference.

  8. A lot of people come and ask me about used kilns they either see for sale or have been offered.  Besides looking for the obvious things mentioned above, one of the most overlooked things I've noticed is that people don't pay attention to the power requirements and somehow end up looking at 3-phase kilns instead of 1-phase that most residential has.

     

    Yes, pretty much any kiln with a sitter can be converted to a digital control box.

  9. I have no science behind this, but if you're crash cooling at the top end of your temp you're going to end up pulling in significantly cooler air through your peep holes - could possibly thermally shock hot elements and brick local to the peeps.  I do it because I already know I'll be working on my kilns continuously through the year, some home ceramicists might not ever touch their equipment until it breaks.

     

    Sometimes you just gotta do what you gotta do.  I've been known to crash cool the student's work in a big gas kiln firing - just leave the damper and burner ports fully open and remove the spys.  Below maybe 500* I'll crack the door open and put on the blowers.  Usually this is only when we are on a time restriction, usually for critique.

  10. For a damp box it likely won't make any difference since I'm assuming it's the type with just a slab of plaster.  If it's slip casting molds then it likely would.

     

    I've always known regular gypsum plaster to be "weaker" than the Pottery #1.  Your mold will degrade faster and won't hold the detail as long.  I also think they have different absorption rates.

  11. You can use either Frit, Gerstley Borate, or make an underglaze with equal parts clay color and flux.  Frits, being fired material usually leave a gritty/sandy texture to the wash, some people use CMC, laundry starch, karo syrup, etc to help.  Usually I use GB and CMC gum solution, sometimes add a little bit of EPK in it too.

     

    Look up Linda Arbuckle's majolica notes, she's got a lot of suggestions for combos of washes.  Most are by volume, not weight.

     

    Here ya go: 

    http://lindaarbuckle.com/handouts/majolica-handout.pdf

    http://ceramicsweb.org/articles/arbucklemajolica.html

  12. since we essentially duplicate the process of forming rocks, all of our ceramics is permanent and will be here until it melts again with some great force of energy.  maybe some sort of ultra hot explosion from warfare, volcano or lava flow, or perhaps heat from asteroid colliding with Earth.  with that said, there is a lot of terrible ceramics out there that will be here forever.

  13. our students do this all the time with both commercial tile and dinnerware from thrift stores.  simply use low-fire commercial glazes and underglazes.  decals also work.

    definitely make sure you test fire the object at the temp you plan on firing to BEFORE you do your entire kiln full of them - sometimes we'll come across a random tile or plate that looks all good, only to find a puddle where it sat in the kiln.  also, not all colors work with this technique - for example greens with chrome sometimes don't fuse well or flux out with the existing glaze

  14. Has anyone got the Bailey electric kiln? I'm looking at the 2327-10, just out of curiosity. 

    http://www.baileypottery.com/kilns/baileyelec2327-10.htm

     

    I'm wondering what people's experiences are with this kiln. Are the elements easy to change? Pros and cons are appreciated.

     

    Thanks!

    pretty sure the top loading Bailey electrics are the same as a Skutt, where elements go directly into the soft brick channel.  It's the front-loaders he now makes that have the element holders similar to an L&L.

     

    Personally, I don't see the issue with a Skutt kilns, I think they are great.  I'm on the West Coast, they are also, so why would I not support them?  I don't really ever have issues where I need help with them, but when I do call Skutt I always have quick help and excellent service.  Have 7 here in studio and know numerous people that own them at home or in other schools.  Seems everyone here always complains about the element setup in them, but seriously how often are you swapping elements?  Once a year, once every other year?  I swap elements all the time with the amount of abuse undergrads throw at my kilns and they are all nearing 20 years old, also with most of their original bricks until recently when I did a full rebuild on a few of them.  Sure it might be easier to pull out a rigid element holder to keep from messing up soft brick, but that hard element holder is going to soak up more energy than the soft brick would - making a less efficient use of the energy going into your work.  

     

    As for those Advancers....drool....I would personally just stick with regular alumina shelves until you are ready for another big investment, since you're looking at investing in a kiln now.

     

    someday I will get some, but man are they expensive.  Actually, I tried getting my studio some Advancers a year ago, but after talking with Marshall at SSFBS, he said they wouldn't work because of the way that we use full hard-brick to stack our kilns -- something about the thermal shock of the heat difference between where the shelf gets sandwiched between brick vs the areas not sandwiched.  Marshall sent me lots of info regarding these shelves and I can definitely see where they would excel and could potentially save lots of money in the long run if taken care of.  Unfortunately, it's hard to convince administrators that spending 3x the cost of something that's already expensive, will be worth it long-term (since our regular SiC shelves already end up around $125/ea for a 12" x 28" x 3/4")

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