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Member Since 15 Mar 2013
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#66223 Stacking Help For Reduction Gas Firing

Posted by jrgpots on 15 September 2014 - 10:29 PM

Marcia, the kiln is a bit backwards. The burners are horizontal on either side of the exit flue. The flames hit the back of the kiln where they are deflected upwards. I stacked 2" posts with 1/4 airspace between posts acting as a bag wall for the first shelf.

The flame was forceful and not licking. I neeed to turn down the air I guess and let the kiln heat up more slowly.

The drawing is the same orientation as the kiln. I am sure it will cause lots of questions.


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#64254 Ki-Seto Glazes

Posted by jrgpots on 10 August 2014 - 01:47 PM

If you want to increase silica in the glaze, use ash from faster growing plants, rice husk for example. Ash from any monocotyledon plant( where the veins in the leaves are parallel) such as grass, bamboo, cattails will have higher amount of silica which may be suffient to reduce/prevent crazing.


#64233 Tenmoku Leaf Bowl Question

Posted by jrgpots on 09 August 2014 - 11:56 PM

I did some surfing and found an article on Konoha-Tenmoku, the technique of leaf bowls.


The master potter, Katsuhisa Yosuda, refined his leaf bowl technique between 1979-90.

If someone wants to call him and ask for his recipe and tricks of his bowls, I bet would gladly give up his secrets........Right?.........:P.

We then would all know how to do this technique.....lol


#64224 I'll Be A Little "scarse" For The Next 14 Days

Posted by jrgpots on 09 August 2014 - 09:10 PM

Many of us live vicariously through events like this. Please post pics of the build so we can enjoy it also.


#64209 Ki-Seto Glazes

Posted by jrgpots on 09 August 2014 - 03:01 PM

When I did 50% ash 50% feldspar I had a hard time getting a full melt up to cone 7, but I found 60% ash and 40% feldspar melted better.

I like you color


#62684 Would Olivine If Added To A Glaze Produce Green Flakes?

Posted by jrgpots on 18 July 2014 - 01:51 AM

I have a good supply of olivine, a magnesium iron silicate also known as paridot. The Insight database calls it a refractory that melts around 2800F. Would olivine dust of about 40 mesh when added to a glaze result in green flecks?

Does anyone have any experiance with it? If not, I will post my test tile results.


#62549 Favorite Glaze Recipes

Posted by jrgpots on 16 July 2014 - 01:00 PM

Wouldn't it be great to encourage the guardians of the forum to add a glaze recipe database where one could add his or her favorite glaze recipe and allow comments on each recipe as others use the recipe, dicussing its characteristics, applications, effects of layering, pros and cons. It would be a great resource..........



#62119 Sick Clay

Posted by jrgpots on 09 July 2014 - 05:08 PM

Yes those letters are real.  As Chris said staph is everywhere. Anywhere mold and midew grows, bacteria will be there competing for food. 


Not all staph is created equal.  Staph epidermatis is a normal bacteria that is on everyone's skin.  It rarely causes problems and there is no reason to get rid of it unless you are headed into surgery.  Most of the bacteria on our skin is protective. They compete with the bad actors like Methicillin resistant Staphalococcus aureas, knowm as MRSA.  The overuse of antibacterial soaps have created the MRSA outbreaks we see today.


There have been many articles showing that playing in the dirt as a child is protective.  In fact children who play in the dirt have fewer allergies as adults.  One could make the arguement that potters should have a better immune system because of their clay exposure.


If someone brought samples of clay into my InstaCare I would love to do the testing. It would break my routine of colds, flues, broken bones.  It could probably be written up as an interesting case study looking at what bacteria is found in ceramics and if pottery would be protective against bad bacteria like MRSA.


Although I have had a little old lady bring in over 100 jars of fecal material, so I could "examine it all."  And yes Chris I did "have the nice young men in their clean white shirts come and take her away." 




#62044 Bad Habits You Would Like To Break.

Posted by jrgpots on 08 July 2014 - 04:45 PM

Have you been spying on me?  I need to search my studio for the hidden cameras.   All I can say is ditto, ibid, and op cit...



#61874 Requirements For Good, Basic Studio

Posted by jrgpots on 06 July 2014 - 06:52 PM

I have my wheel facing the wall with a mirror mounted on the wall, so I can see the shape of the piece being thrown. Consider moving the slab building table to the middle of the room so you can access it from multiple sides.


#61064 How Do You Run Clay Through Your Slab Roller?

Posted by jrgpots on 17 June 2014 - 11:32 PM

Can you envelope(sandwich) the clay with a piece of free canvas that would go inside the slab roller's canvas. You could then rotate this envelope 90° after each pass of the slab roller?


#60570 Glaze Practice Tile(S)

Posted by jrgpots on 10 June 2014 - 11:52 PM

Perhaps a class mosaic of all the techniques. The student tiles demonstrating the techniques the best could be part of the mosaic.


#60563 Nuka Ash Crackle Cone 6 Glaze

Posted by jrgpots on 10 June 2014 - 10:44 PM

What kind of glaze would you use to maintain that crawl?

 I made a glaze with  a local bentonite clay.  The base glaze is a nice transparent camel color. But then  I added 10% rio. I  layered theash glaze  on top.  The ash glaze absorbed some of the rio and turned a bit yellow.  But it did not run and the base glaze was visible between the cracks. I'm hoping to get a better base glaze that brings out the ash glaze more.




local bentonite             76

Neph sys                     18

gersley borate               6


Total                          100


add 10% RIO.




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#60505 Nuka Ash Crackle Cone 6 Glaze

Posted by jrgpots on 10 June 2014 - 04:57 PM

Here is my first successful ash glaze.  I call it Nuka crackle.  it is fired to  ^6 oxidation.  It is placed on thick and cracks as it dries. The top of the tile is double dipped while the bottom is single dipped. It does not drip, but has a great matte finish.


The recipe is:


Soda Feldspar                40

Tumbleweed ash             26.7

Whiting                            13.3

EPK                                 13.3

Frit 3124                            6.7


Total                               100


I'm thinking of using it over a darker glaze so the color is seen through the cracks.


Jedcrackle tile.jpg

#60402 Glaze Making/ Testing Again!

Posted by jrgpots on 09 June 2014 - 06:25 PM

I second the digitalfire site and insight.  Duncan Shearer has an intro to glaze chemisrty... http://www.duncanshe...echemistry.html . It's a bit basic.


Once you recognize the parts of the glaze, it's not so overwhelming. 

1. fluxes,

2. glass makers,

3. stabilizers,

4. opacifiers, 

5. colorants.


I have made up flash cards with the names of the glaze compounds with their "pottery name," common name and/or chemical name, catagory #1- #5, and a brief discription to help me know its properties and function.  They work for me.  It may help you.


Many of us are in the same boat.  The great news is that You are on your way..you are doing it.