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Ginny C

Member Since 02 Apr 2010
Offline Last Active Mar 22 2017 01:40 PM

Topics I've Started

Blisters Worse After Re-Firing

13 October 2016 - 10:23 PM

Lovely vase came out with popped blisters all over it. (Electric kiln, B-Mix cone 5-6 clay,  bisqued to 04.  Then glaze fired to cone 6.)


I ground them down some with a dremel, covered each with 2 dabs of clear glaze and re-fired. Now the blisters look like the wart I had as a child, made of lots of little columns crammed up together.  Really ugly, although one visitor said it was interesting, and I should just title it "Vase—Warts and All"  


 Maybe it needs to go to cone 7?   Should I give it one more try, re-firing it again??   If so, should the whole pot get a new coat of glaze, rather than just over the warts?


Other pieces from the same clay but different glazes came out fine.  The glaze was somewhat thick on this vase. Might that have caused the blisters?




Attached File  Screen Shot 2016-10-13 at 11.20.38 PM.png   273.17KB   3 downloads




Hollow Die Extruder. Clay Not "healing"

03 September 2016 - 12:44 PM

I just purchased some hollow dies for a square wall-mounted extruder in a shared pottery space. (No one in charge of the room. It's a non-profit Artisan Learning Center, well equipped but no one using it now was there in the beginning.) The only dies they had previously were for solid items. I want to extrude hollow shapes, and I was excited to try the new dies this morning, but it was a failure! Instead of one hollow tube it produced two halves of a tube, completely separate from each other.


The dies came with a cross-piece with three bolts to fit into the die and the center piece. I installed the die in what seemed the logical way, with the connecting bar above the die, and loaded nice soft B-Mix clay.  The shape came out in 2 sections, all the time.    


The cross piece is flat (maybe 1/16th inch thick) and about 1 1/2 inches tall.  Seems like a much smaller connection would be better at letting the clay get itself back together in time!!


Any suggestions?? What did I do wrong? Thanks for any help.



Additives For Old Glazes

16 August 2016 - 10:35 AM

I'm spending time this month at a community pottery room and the glazes are mostly a mess.  No one is in charge of them. The good  potters mostly bring their own, and the beginners just struggle to brush on from the buckets of various glazes.  They have been mixed from dry but have sat for several years. I know to scrape up the settled part, sieve the whole thing, and add some epsom salt solution to cut down on the settling.


However, most people want to brush the glazes, and they dry instantly on the pots, making a mess. I have read about using gum solution and will order some, I think, but in a pinch, can I just add some glycerin?  And how about some vinegar, also??  Do I have to learn how to measure specific gravity??


There are lots of bags of dry glazes in the cupboard.  All of them are Laguna MS for Cone 5-6. They would like me to mix them up.  There is Bentonite, so I will use that (although the colors of these glazes are not what I would choose!!).   But to make them suitable for brushing, should I add gum along with the bentonite?  I've read that the gum in powder form must be mixed with water and used as all or part of the water when mixing the glaze.  (There are lots of other glaze ingredients stored there, so in the past someone knew how to use them!)


Ideally, I would think I should mix the glazes into two containers, one for brushing and one for dipping, with different additives. AND LABEL THEM AS SUCH!


Can you wonderful people send me some suggestions and maybe some links to clearly explained instructions? 



Glazing Mugs With A Different Glaze On The Handle

18 June 2016 - 05:01 PM

How does Mike Jabbur glaze his beautiful mugs? I can't figure it out! The gorgeous handles are already attached, of course, but the glaze on the body of the mug is different from that on the handle and inside. Anyone know??

Will Mike Jabbur share his technique?


Ginny Clark

Large Platter Broke In Half In Bisque Firing. Anything To Do With It?

29 April 2016 - 08:18 PM

Lots of work went into this large (15" diameter) agate ware platter, but it broke clean in half during the bisque firing! I had it sitting on sheets of Bullseye kiln liner paper to allow it to slide on the kiln shelf. 


I'm sure it is now headed for the driveway, unless someone can suggest another use, or even a way to repair it. (Ha!)




Just to show what it would look like with a clear glaze, here's another piece I made earlier:



FYI, the patterned clay strips are placed on a thin slab of the same clay (Laguna B-Mix for cone 5) and rolled hard until they are basically one unit. Then this platter was cut to shape and placed on a canvas sling to form the gentle curve while drying to leather hard.  I placed a ware board under it (under the sling) at the right distance to give it a flat bottom.  In case someone thinks it wasn't dry...no chance! I'm sure it was thoroughly dry.   The process seemed to work, until...I opened the kiln!