PLEASE ALLOW ME TO INTRODUCE MYSELF,

I’M A MAN OF CLAY AND GLAZE

PUSHED MUD AROUND FOR SEVENTY YEARS

OR TWENTY FIVE THOUSAND DAYS.

Robin Hopper is a man of many parts, mostly worn out, rusty or dysfunctional, due to a lifetime of excesses! He started working with clay at the age of three and is still doing it over 70 years later. His lengthy, peripatetic career as a mudpusher has included side trips into working as a Professional Actor, Stage Designer, Property Maker, Stage Manager, Stage Carpenter, Grocer, Greengrocer, Jazz Musician, Teapot, Wine and Beer-Bottle, Trumpet, Trombone and Bugle Player, European Travel Guide, Founder of Several Clay/Art/Craft Organizations, Alchemist, Geologist, Primatologist, Linguist, Ornithologist, Botanist, Ceramic Historian, Educator, Author, Garden Designer, Lecturer on Japanese Garden Design, Laborer and Star of Stage, Screen and Potter’s Wheel!

Wednesday, March 14, 2012

MATERIALS MAN: PART 9: RUTILE

WEDNESDAY, 14TH MARCH, 2012


TODAY'S POST IS BROUGHT TO YOU COURTESY OF:  RUTILE.                                                                  




RUTILE CRYSTALS IN A MATRIX OF SMOKY QUARTZ







RUTILE IS A NATURAL SOURCE OF TITANIUM, USUALLY CONTAINING SOME IMPURITIES IN THE FORM OF IRON AND ILMENITE, AND VERY OCCASIONALLY CHROMIUM AND VANADIUM.  IT IS USED TO PRODUCE MODIFIED IRON COLORS SUCH AS YELLOW TO BROWN IN OXIDATION, AND COOL BLUES, BLUE-GREYS TO STREAKY PURPLE IN REDUCTION ATMOSPHERES. IT STRONGLY AFFECTS OTHER COLORS, TURNING COBALT TO GREEN, IRON TO GOLD AND COPPER TO YELLOW GREEN.  THE COMBINATIONS OF YELLOW GREENS MADE WITH RUTILE AND COPPER SEEM TO BE MORE OR LESS UNAFFECTED BY REDUCTION. RUTILE ALSO PRODUCES CRYSTALLINE REACTIONS WITH MANY GLAZE BASES. PARTICULARLY THE ALKALINE EARTHS OF BARIUM, STRONTIUM, LITHIUM, CALCIUM AND ALSO ZINC. COMBINATIONS OF PURIFIED TITANIUM, ZINC OXIDE, NEPHELINE SYENITE AND OTHER FELDSPARS FORM THE BASIS OF A LARGE PERCENTAGE OF CRYSTALLINE GLAZES. IN CONJUNCTION WITH BORON, RUTILE WILL LIKELY ALSO PRODUCE OPALESCENT GLAZES.

RUTILE IS ALSO USED  AS AN  OPACIFIER IN THE DEVELOPMENT MANY OPAQUE  OR CLOUDY GLAZES. GREAT CARE SHOULD BE TAKEN IN ITS USE AS AN OPACIFIER BECAUSE OF ITS PREVIOUSLY MENTIONED EFFECTS ON OTHER COLORANTS.  IN THESE CASES, TIN OXIDE AND ZIRCONIUM BASED OPACIFIERS ARE PROBABLY PREFERABLE. COMBINATIONS OF TIN OXIDE AND TITANIUM DIOXIDE PRODUCE PARTICULARLY BEAUTIFUL VARIATIONS ON IVORY COLORS FROM COOL BLUE-WHITE TO WARM GOLD-WHITE IN BOTH OXIDATION AND REDUCTION.

SMALL PERCENTAGES (2% - 5%) OF RUTILE MAKE GREAT ADDITIONS TO  ELECTRIC FIRED GLAZES IN THE CONE 6 - 10 RANGE BY CREATING MICRO-CRYSTALS THAT GIVE TEXTURED SURFACES.  GRANULAR RUTILE, AND ITS COUSIN, GRANULAR ILMENITE, BOTH ADD TO THE TACTILE AND TEXTURAL QUALITIES OF THE GLAZE.

MOST COMMERCIALLY PRODUCED RUTILE IS EXTRACTED FROM AUSTRALIAN BEACH SANDS.





MICRO-CRYSTALLINE DEVELOPMENT WITH IRON AND RUTILE
GLAZE TESTS AND PHOTOS BY TONY MOCHIZUKI



MICRO-CRYSTALLINE DEVELOPMENT WITH IRON AND RUTILE


MICRO-CRYSTALLINE DEVELOPMENT WITH IRON, COPPER AND RUTILE

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SOME COLORS THAT MAY BE EXPECTED FROM RUTILE
IN VARYING CONCENTRATIONS AND ATMOSPHERIC FIRING CONDITIONS

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IN MY NEXT POST, ON FRIDAY, MARCH 16TH, WE WILL LOOK AT CHROMIUM, LAST OF THE SEVEN MOST USED COLORANTS IN CERAMIC COLOR DEVELOPMENT.  BLENDED TOGETHER WITH OPACIFIERS, STABILIZERS, FLUXES, CLAYS AND TEXTURAL MATERIALS, THEY PRODUCE MOST OF THE STAINS THAT ARE USED FOR COLORING CERAMIC GLAZES AT A WIDE VARIETY OF TEMPERATURES.











4 comments:

  1. Hi Robin, I just found your blog from a link on Carole Epp's blog. I'll be checking in from time to time - one of your Clematis decorated pots has pride of place in my home here in Sydney Australia.

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  2. Hi Robin;
    I do love Rutile. Are you daffodils up?

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  3. DAFFODILS, CROCUS, SHOWDROPS, CYCLAMEN, PRIMULAS, SQUILLS, HELLEBORES BY THE TON, CHERRY BLOSSOMS, CAMELLIAS AND EARLY RHODODENDRONS ARE ALL UP AND BLOOMING BEAUTIFULLY. MOST OF THE TIME I DON'T TALK ABOUT THE GARDEN AT THIS TIME OF YEAR WHEN SO MUCH OF THE WORLD IS STILL UNDER A LARGE DUMPING OF SNOW AND IT SEEMS UNFAIR. THEY WILL SOON CATCH UP THOUGH. THE GARDEN IS LIKE A BIRD SANCTUARY AS WELL RIGHT NOW. I WILL START GARDEN OVERVIEWS NEXT MONTH SOME TIME, AFTER MY ROVING REPORTER GIG AT THE NCECA CONFERENCE IN SEATTLE. THERE WILL BE PLENTY TO TALK ABOUT. BEST WISHES, R

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  4. HI ANNA,

    TO GET THE MOST OUT OF THIS PARTICULAR BLOG, IT IS BEST TO GO BACK TO THE BEGINNING. THE FIRST POSTING SETS THE SCENE, THE REST TELLS THE STORY IN ITS GLOBAL MEANDERINGS. IT IS A COMBINATION OF NEWS, AUTOBIOGRAPHY AND TEACHINGS. BEST WISHES, ROBIN

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