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bciskepottery

Member Since 28 Jun 2010
Offline Last Active Yesterday, 11:13 PM
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#75804 Setting A Kiln To Start Firing At Night? - Finishing When I Am Awake? - Nest...

Posted by bciskepottery on 19 February 2015 - 11:01 PM

I generally fire overnight.  I start and monitor the kiln until bedtime.  I time the firings so they have about two hours to completion when I wake up so I can be there to make sure things turn off.  I crack the garage door a bit to allow warm air to escape -- especially in summer time.  From time to  time I've thought about a baby monitor so I could check temperature etc. from computer, but have not gotten around to doing so.  Just finished 100th firing. 




#75716 Photography Backgrounds

Posted by bciskepottery on 18 February 2015 - 09:10 PM

If you can afford just the background paper . . . http://www.amazon.co...N0Z85QQYYKFKG00 . . . you can get reasonably good pictures outside using natural light.  Or, in a pinch, take an old white window shade and apply an even coat of flat light grey spray paint, let it dry, and use that until you can afford a higher cost set up. 

 

You might also ask any professional photographers to do the photos . . . perhaps in exchange for a mug or plate.  Bartering still works. 




#75547 How Is Your Local Pottery Community For Social And Professional Interaction?

Posted by bciskepottery on 16 February 2015 - 09:41 AM

Time to follow mom's advice:  If you don't have anything nice to say, don't say anything at all.




#75435 Picasso Ceramics Exhibition At Kennedy Center, Washington, Dc (Free)

Posted by bciskepottery on 13 February 2015 - 05:56 PM

http://www.kennedy-c...iberia-picasso/

Picasso Ceramist and the Mediterranean

Mar. 4-22 | Atrium and Atrium Foyers

Picasso Ceramist and the Mediterranean is a carefully curated selection of more than 140 of Pablo Picasso's ceramic pieces that reveal how the prolific artist reshaped the very notions of how clay could be used. Reflecting the artist's strong attraction to Mediterranean colors, shapes, and mythological creatures, the exhibition is the first of its kind to be shown in the United States. During Picasso's long career, he explored many forms of visual art: painting, sculpture, lithography, etching, collage, stage and costume design, poetry, and ceramics. He initially experimented with clay in 1900, but it was during the years after World War II that he developed an intense interest in the medium. At the time, he lived in southern France, where clay deposits had been exploited since pre-Roman times. During his lifetime, he produced some 4,500 plates, vessels, and other ceramic creations.

This exhibition was originally conceived for "Marseille-Provence 2013," the yearlong celebration of Marseille's reign as Cultural Capital of Europe and presented in Aubagne. In 2014, the exhibition traveled to the National Museum of Ceramics in Sèvres, near Paris, where it was the most successful show in the museum's history. It is curated by Joséphine Matamoros and Bruno Gaudichon, and is made possible by the generous participation of private collectors.


#74869 Very Pale Cream Glaze Tests

Posted by bciskepottery on 05 February 2015 - 09:17 AM

Attached File  antique_white.JPG   129.74KB   3 downloads

So, this is the third time I've typed and uploaded this post . . . and the last time I'll try.

Here is a glaze called Antique White -- Cone 6, oxidation. The bowl is a dark brown stoneware (Standard 266).

Antique White
Nepheline Syenite, 41.7%
Silica, 16.7%
Gerstley Borate, 25%
EPK Kaolin, 8.3%
Whiting, 8.3%
Total, 100%

Bentonite, 2.2%
Tin Oxide, 8.3%
Red Iron Oxide, 0.9%

The dash of RIO takes the harshness off the white of the Tin Oxide. Those two may work with your base glaze.


#74866 Kiln Opening Temp

Posted by bciskepottery on 05 February 2015 - 08:15 AM

For glaze loads, I like to wait until the kiln is around 100F.  The thermocouple readings are of the air temperature in the kiln; your wares and shelves are likely hotter than that reading.  My thermocouple have a protective sheath; so, they have an adjustment in the controller to compensate for that as they are not reading the actual inside temperature and the offset helps prevent over-firing.  And, for the most part, I'm over the "Christmas" rush of every kiln firing  -- mostly because my kiln is electric and I've settled on a smaller palette of glazes that are consistent in firing.  Letting the kiln cool a bit longer is no big deal. 

 

If you induce pinging by opening the kiln when it was too hot and allowing a rush of cold air . . . that does not mean the glaze would have pinged if it had been allowed to cool further before opening.  Some glazes will ping regardless.  Some pinging can be from operator error. 




#74774 Glaze Fit Issue On Terracotta Slip

Posted by bciskepottery on 03 February 2015 - 09:51 PM

The slip is not vitrified and the glazes, while delaying seepage, do not compensate for the lack of vitrification. Standard shows an absorbency rate of 5% for the terra cotta slip. That is still rather porous at cone 04. For water-tight, you need to get to 2% or less for absorbency -- preferably in the 1% range -- that is my comfort level for vases and other forms holding water for long periods.

Are you just using a liner glaze? or glazing both interior/exterior? You could try bisque firing at higher temperature -- maybe consult with Standard to see how far you could push the slip body. Some folks working in terra cotta apply terra sig to the bottoms of pots to help seal the clay body; again, that can delay seepage but it will not compensate for an unvitrified clay body.


#74737 Amaco Chalks?

Posted by bciskepottery on 03 February 2015 - 07:52 AM

You can make your own by adding mason stains in the color of your choice to dry white porcelain clay body, add water, wedge to blend the colors, and roll into a pencil/crayon.  Let them dry and use them as a stick of chalk.




#74577 Submit Your Community Challenge Ideas

Posted by bciskepottery on 31 January 2015 - 08:23 PM

Pres . . . would you consider pinning this and the community challenge #1 post so they don't get lost among the other posts?




#74567 Purple Haze, Opps No Glaze

Posted by bciskepottery on 31 January 2015 - 05:04 PM

Apply 3 coats of glaze with a brush.
T.

 
No, seriously!  I can't dip it or spray it???


You can get dry glaze . . . and mix it yourself to dip or spray. No need to pay for shipping water.


#74513 Trying To Avoid Refiring A Teapot

Posted by bciskepottery on 30 January 2015 - 07:24 PM

Go with it as is; I would not chance a refire. On my (few and far between) teapots, I wax the holes so the clay is bare. If you rinse the teapot out after use with hot water, soap, it will be okay -- not a whole lot different than a bare clay gallery on a lidded container. Yinxing teapots are unglazed on the insides; they are usually used for just one type of tea and become seasoned from repeated use.


#74394 Pitting

Posted by bciskepottery on 29 January 2015 - 10:50 AM

Refiring to fix glaze defects (like pitting) is generally a crapshoot. It may work, it may not . . . I've seen it go both ways (though more often in the not category). Just approach it as a test . . . if it works, then it is a good test, if it does not, it is still a good test because you learned how your glazes will look refired.

You may need to go hotter (longer soak at cone 5, maybe go to cone 6), not cooler (cone lower) to even out the glaze. Firing lower, the glaze may not melt enough to become viscous enough to heal over the pitting. Plus, you don't want to risk the rest of the kiln with underfired work at a lower cone and your glazes will not look the same at that temperature.


#74247 Dishwasher Safe

Posted by bciskepottery on 27 January 2015 - 10:06 PM

If your clay vitrifies at cone 5, unglazed should not be a problem on the bottoms.  Laguna has absorbency, shrinkage and other data for their clays on their website.  I try to keep absorbency to 2% or less, but shoot for clay bodies with 1%.  Stoneware or porcelain.  If the glazes are rated Cone 5/6, likely okay . . . but it may be worth doing a couple of the durability tests just to make sure  -- running them through the dishwasher repeatedly, lemon slice on glazed surface to see if it discolors, etc.  Mastering Cone 6 Glazes lists tests you can do at home; these are preliminary tests, not finals, though.  Other books also describe them.  Try a google search for glaze durability testing.  If they fail  the at home tests, find other glazes.  For finals -- especially for leaching (although with commercial glazes you really don't know what to test for as you don't know what the glaze is made of), you need to submit to a laboratory.




#74124 Reasonable Fee For An Accountant?

Posted by bciskepottery on 26 January 2015 - 07:31 AM

I will refrain from any jokes about "reasonable fee for an accountant" being an oxymoron.  (It's okay, I work with accountants every day, just don't want to be one.)




#74093 Dream Tool

Posted by bciskepottery on 25 January 2015 - 06:21 PM

Attached File  tools.JPG   80.04KB   6 downloads

 

These aren't "dream" tools . . . but tools I made (like Paul) out of necessity.  I am mostly a hand-builder and needed tools to help seal seams of taller cylinders.  They also work great -- especially the ones with roller balls -- on bellying out wares.  Simple. Inexpensive.