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bciskepottery

Member Since 28 Jun 2010
Offline Last Active Yesterday, 08:32 PM
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#122865 What Exactly Is Shino

Posted by bciskepottery on 24 February 2017 - 10:53 AM

Forget about Wikipedia . . . start here: https://euancraig.bl...s-of-shino.html

There are the Japanese shinos . . . very traditional. And, there are American shinos . . . very different, google for Malcolm Davis to see his work on carbon-trapping shinos. You can spend a lifetime in pursuit of shino, google Hank Murrow. Same differences as Japanese raku and American raku.

What is offered in stores in pre-mixed containers of all the rainbow's colors are not shinos. Same for their celadons. They are just nice (mostly) looking glazes that have the apparent look of the originals.


#122772 Resist Over Glaze?

Posted by bciskepottery on 22 February 2017 - 08:09 PM

Ask Hamada. He did it for years.


Only if you are into séances.


#122771 Trouble Getting Kiln Information

Posted by bciskepottery on 22 February 2017 - 08:08 PM

Your pictures show a good deal of information:

The kiln requires 45 amps; so your circuit will need a 60 amp circuit. Find a good electrician to look over the controller and do your wiring.
Max temperature looks to be 2300F -- cone 8, so your top temperature may be cone 6.
The kiln sitter is an older, Dawson manual model. Here is the manual for it: http://jenkenkilns.c...F/dawson-PK.pdfIt has three heating levels - low, medium, high. A starting firing schedule is two hours low, two hours medium, then high until your reach temperature. You will need to use cones to determine when you reach temperature.

The Jen-Ken site has a number of technical manuals; you might have to skim through them to see which might be helpful as one is not listed for the D-24 model.

Check with potters in your area to see if any fire a manual kiln. They can tell you a lot about how to proceed. There are also good books out there on firing an electric kiln that might be helpful.


#122563 Stoneware Clay Properties

Posted by bciskepottery on 20 February 2017 - 11:54 AM

Above that however, I think an industry standard test needs to be in place that rates plasticity by a numerical scale. I was reading the thread about Continental Clay, and the comment was made that no technical information was given for the products. Clay arts is the only trade that I know of that has such lax standards and quality control for products. Kudos to the makers who care enough to at least supply some working information.

 

Well, with the terrific job industry already does with standards -- e.g., this clay body works well between cones 5 and 10 -- I'm sure they'd do a bang up job with plasticity ratings (-1 if the clay has dried out while sitting on the shelf for over 12 months and +10 if made yesterday and still mushy in the bag).  Clay arts doesn't seem to do well with standards (just look at the various glaze books and see the variations in limits for safe and durable glazes or see if there common agreement on what is food-safe, etc.).  Mostly because clay arts represent the bottom of the user world and carry none of the impact that large volume consumers (e.g., commercial producers) can demand from manufacturers.  In short, we get the left overs, are the last to know when composition of materials change, etc. because we are a marginal percentage of their bottom lines.  And, on a customer-by-customer basis, they will make a batch to whatever specs we give them, so those who have specific requirements can get what they want -- for example, Mark C. has his distributor mix half his clay to be softer knowing it will be sitting/aging for six months before he uses that part of the supply.  Such a rating may be useful to some potters like yourself who want a specific type of clay body for a specific technique, e.g., crystalline growth, but most would not have any idea of how to use that information.  And, as the clay ages, the rating is likely to become outdated and/or no longer precise. 

 

Standards should be reserved for things that affect health, safety; plasticity does not rise to that level of concern where we ask for and submit to regulation. 


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#122561 Looking For Suggestions

Posted by bciskepottery on 20 February 2017 - 11:23 AM

Students with a disability (or their minor parents/guardians or school counselor) must inform the instructor if the student needs/expects accommodations.  And he/she should have that discussion with you at the start of the class term. 

 

For your next class, on the first day specifically ask that any students with a disability that needs accommodations speak to you separately and from there you and the student can jointly work out a plan.  But if they don't tell you, and you are not a trained diagnostician, then it can't be your fault later on. 

 

Students fail to inform their instructors of their need for accommodation; too many times, my wife (a retired college instructor) found this out when explaining to the student why he/she was failing the course and then student telling her for the first time, "But I am supposed to get an accommodation for longer test periods because of __________." 




#122493 Stoneware Clay Properties

Posted by bciskepottery on 18 February 2017 - 07:56 PM

How are you measuring "force" -- by your own feelings while throwing or through some type of device that provides empirical data? In your comparisons, are all particle sizes constant with the only difference being the particle size of fireclay? And all other variables, e.g., wetness, are also constant? Just trying to limit the number of variables at play . . .

Wondering, if I gave a student a bag of Standard 181/182 stoneware and told him/her it was a Standard porcelain, would they know the difference? (You could likely pick two clays from any manufacturer, not singling out Standard). We seem to have so many preconceptions of how a clay should behave based on anecdotes or comparisons ("throws like crème cheese") that it may color our judgment or create a set of expectations.


#122211 How Do I See My Past Posts?

Posted by bciskepottery on 13 February 2017 - 06:37 AM

First posts must be approved by one of the forum moderators before they appear.


#122170 Surface Technique With Slip

Posted by bciskepottery on 12 February 2017 - 12:35 PM

You have found "a" technique, not "the" technique. There are many ways to achieve a distressed look -- and you do not necessarily have to take a wire brush to your clay or use some overseas formulated heavy grog clay. Yes, the clay body can help -- but you can also use clay slips (think layers not single applications; think thin slip and thick slip), different types of brushes for application -- stiff bristles vs soft bristles, long vs short nap, dry vs wet; dry-looking glazes, engobes, oxide and mason stain washes, tools (spackling knives and plaster tools for application, cleaning the blade vs leaving some slip on the harden and give an irregular surface for the next application), and multiple firings to achieve the look (although you can do it with single firings, too).

It takes practice and repetition to learn to relax while applying the slips, etc. Sometimes you get lucky -- I remember one day my hand cramped while applying slip and the brush dropped on the slab and gave the most unusual pattern. Many of these techniques require patience -- working with the clay is ready to be manipulated -- you can't force the look. Keep practicing and experimenting.

A couple to look at . . .

Lana Wilson (she is known for more than magic water) http://lwilso2.other...s.com/home.html

Jim Robison http://www.boothhousegallery.co.uk/Also, his book with Ian Marsh "Slab Techniques"

Eric Serritella http://ericserritella.com/eric/

https://youtu.be/ueDTA6dPGA4


#121943 North Carolina Wood Fire Conference

Posted by bciskepottery on 08 February 2017 - 07:47 PM

http://www.woodfirenc.com/

If you like wood fire, you may want to check this out. Opportunities to both fire and meet.


#121851 Would Reduction Firing Make Pottery Harder/stronger?

Posted by bciskepottery on 06 February 2017 - 07:31 PM

From Mitch Iburg's Etsy site . . .

Thrown native California clay
Wood Fired to 2150 degrees F.
Cooled in a reduction atmosphere
No applied glaze

Made from an iron rich earthenware harvested near Comptche, CA and used without any additions. This clay is formed by erosion of sedimentary rocks belonging to California's Northern Coast Mountain Range - approximately 60-150 million years old. Screened only to remove large stones and organic matter. Small stones of shale, sandstone, and mudstone in the clay melt out during the firing, creating minor protrusions on the surface and retaining a visceral reference to the landscape and history of its origin.

Fired to 2100 f. in a wood burning kiln for 42 hours using Ponderosa Pine and Manzanita. Each piece was loaded in a small bed of rice hulls - a local agricultural byproduct which, when used in the kiln, prevents the work from sticking to the shelves and creates iridescent color and textural variation.

All color variation results from naturally occurring iron in the clay and its reaction to temperature and oxygen throughout the firing.

Water Tight, Food Safe


#121399 Commercial Cone 6 Porcelain & Decoration With Blue Glaze

Posted by bciskepottery on 28 January 2017 - 10:08 PM

Blue is applied by brush as a cobalt stain (with some frit so it adheres during bisque), then a clear glaze over. The blue is not a glaze by itself.

For white, use porcelain or a porcelain slip over stoneware. Stonewares tend toward ivory, not white.


#121326 Youtube Video Potters

Posted by bciskepottery on 27 January 2017 - 08:13 PM

From an instructional standpoint -- both youtube and workshop -- Bill Van Gilder. He can teach. And he makes great functional ware. Robin Hopper is another teaching potter or potter teacher -- not much youtube but good DVDs.


#120726 Complete Beginner, Epic Fail When Firing

Posted by bciskepottery on 16 January 2017 - 08:39 PM

The clay was over-fired.  Pugging it had nothing to do with the result.

 

Your shelves might be salvaged . . . depends on how deep the clay melted into the shelf.  Wearing appropriate safety gear, remove the items and grind down the shelf -- use an angle grinder if the clay did not melt into the shelf.  If nothing else, remove/grind away all the melted clay and kiln wash to get the shelf completely clean, then flip it over an use the other side instead.  But you won't know until  the charred remains are removed. 

 

Is it possible you programmed the kiln to cone 6 instead of 06?  Did the kiln turn off properly at peak temperature?  How long was the firing? 




#120675 Is Cone 4-10 Clay Fired To Cone 4 Underfired?

Posted by bciskepottery on 16 January 2017 - 08:08 AM

i like the fact that reality does not scare you, you have the guts to tell the emperor he is nude.

 

 

Unfortunately, the emperors (e.g., clay manufacturers) likely know this and continue to do so regardless for whatever reasons, including the one we continue to buy what they produce.  If they see a benefit to standards, they would have done so years ago. 




#120070 Fired Too Much? Or Not Enough? Help!

Posted by bciskepottery on 07 January 2017 - 02:17 PM

The trees pictured seem to be a fairly common and popular item in "paint your pottery" shops; I believe the form can be either slip cast at the shop or bought premade/bisque-fired.

The white is a glitter-type add-on after the glaze firing and the twinkle lights are installed.

http://www.clay-king...ges/holiday.htm

And, just because there is not a recent log on doesn't mean the member has not come back to view threads as a guest.