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Member Since 15 Mar 2013
Offline Last Active Today, 07:48 PM

Topics I've Started

Let Me Show Off My Latest Raw Material

16 April 2014 - 10:38 PM

I went over Ute Pass Colorado last summer. The east side of the mountain is granite but the west side is sedimentary rock. There was one layer of black heavily organic shale or mudstone.  I collected about 5 gallons of the stuff, brought it home, and ran it through the ball mill.  The first picture is of the raw material.  When water was added to the milled material it formed a clay.  It had poor plasticity.  I made a 10 cm bar of the black clay and bisque fired it.  It's color was bright orange Terra cotta.  I then fired it to cone 6 anticipating that it would melt before cone 6.  But as seen in the second picture it did not melt.  It vitrified and the surface is a bit shiny.  The color is a milk chocolate with a hint of orange.  The bar before drying was 10 cm long and after cone 6 firing was 9.7 cm.  There was very little shrinkage ( about 3%).


Does anyone have an idea what this stuff is? I looked up a Geological survey of the area which said it was sedimentary deposits from the tertiary age. There is a Molybdenum mine just up the ridge from this deposit. 


Any ideas how to make this a workable clay. As I said it is not very plastic. What would I need to add?



Diy Burners

24 March 2014 - 10:14 PM

I just tested the twin burners for my small electric-gas conversion.  I haven't set the baffles on the air intakes yet. So I used a little foil to reduce the air flow.  The burners are burning at 3 psi in the second pic.


I have cut three holes in  my small electric kiln (18" dia x 24" ht.)  I still need to set the bricks for the chimney and buy a thermcoupler. 


I just wanted to show my progress.



Zinc Oxide Wrap

20 March 2014 - 03:14 PM

This is going to sound a bit strange...  I have some old expired wound wrap that is impregnated with zinc oxide, calamine lotion, and guar gum.  The wrap is a piece of 3 " wide gauze x 10 yrds long.  I thought about trying to use it in a number of  ways:

     1.  Place on raku pots during reduction phase.

     2. Wrap on ware  prior to saggar firing or place the gauze in bottom of the saggar.

     3. Place on top of glaze in a regular cone 6 firing. 


     4.  Throw the wrap away without using it.



Any thoughts?



Native Clay Glaze

04 March 2014 - 09:38 PM

About 2 months ago I made a terra sig from local clay.  It's a magnesium and iron rich bentonite. In its raw state it is purple and chocolate brown in oxidation. I don't know what it looks like in reduction yet.  It melt at cone 4-5.  I did triaxial blending of Gerstley borate, Nepheline syenite, and the clay with the results below.  The glaze has a satin finish with two coats and semi gloss finish with one coat.  It has a pleasing texture.  I like the tile that has the hole in the test tube.  Lemon juice test showed no discolorations.  There is no crazing.


Recipe: Gerstley bborate                6.52

            Neph syenite                     15.22

            local clay/bentonite           78.26


It was applied on bone dry clay and single -fired to reduce problems with the high bentonite and its COE.  I think I have my first stable home grown base glaze.


What colorants do you think I should try next?  


I have thought about adding RIO 6 - 8% to see if it will make a nice satin tenmuko that I could use as the base glase  for a cone 6 oil spot or hares hair glaze.  That is my aspiration.


Imput, critique, gut reactions are greatly appreciated.


JedAttached File  bentonite glaze.jpg   57.51KB   2 downloads

Yearly Ash Burning

25 February 2014 - 11:09 PM

Last night I was hovering over my 55 gal drum as  flames shoot into the air.  The heat was intense as dry tumbleweeds burst into flame.  For about two hours I stuffed tumbleweed after tumbleweed into the conflagration as they joined in  the sacrificial flames of night.........I really enjoyed it. It is a great yearly ritual.   Every year I get thousands of tumbleweeds in my yard with the wind. They end up burning in the drum.   I have about 10 inches of ash in the bottom of the drum this AM. 


It makes a beatiful green "celadon-like" transparent glaze with custer feldspar or granite dust at cone 6 oxidation...


I am willing to give away some of this Great resource of the SouthWest to anyone who might want to try it out.  If interested, drop me a E-mail.  Otherwise, I wil continue to stock pile.