Jump to content


Member Since 15 Mar 2013
Offline Last Active Today, 12:08 AM

#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?


#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.




Attached Thumbnails

  • 20140610_210501.jpg

#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.



#60052 Glaze Layering Using Different Manufactors Products

Posted by jrgpots on 05 June 2014 - 02:49 PM

On the back side of the tlles mark your glaze combo. Use a toothpick dipped in Red iron oxide wash as a marker.  Or you can buy an old style ink well pen using the red iron oxide wash as the ink.



#58899 Firing Clay Experiments Going Wrong, Please Help

Posted by jrgpots on 20 May 2014 - 07:22 PM

When I was about 4 y/o, Our family went to the Yuba river in Northern CA. We kids knew we could swim because our favorite TV show was "The Aquanauts." That summer we had watched all of the episodes, so naturally we knew all about swimming. They made swimming look so easy. Unfortunantly, we had nevergotten our feet wet, much less learned to swim. I wish my mother had had a movie camera as my father dragged out of the water 4 half-drownd water-logged kids.

My point is that this forum is like The Aquanauts...One can learn all about clay. There are people here that make it look so easy. BUT, we all start at the same point...by getting our feet wet.

So, the water is warm. Welcome to the beach. It's a bit rocky at first.


#58726 Single Firing In A 3.5 Cf Gas Conversion Kiln.

Posted by jrgpots on 17 May 2014 - 04:04 PM

3 1/2 hours into firing, turned on second burner. Waiting for the red glow.

Sorry for the blow-by-blow tracking of a simple firing. I'm just excited....a little.... OK, really excited.


#58677 Basalt Spots / Specks

Posted by jrgpots on 16 May 2014 - 06:05 PM

I have added basalt dust to Laguna Half and half cone 5-6 clay body.  In oxidation it creates a cookie and cream speckle pattern.  I sieved with a 20 mesh and used about 150 gm of basalt to 1000 gm of premixed clay.  You can use larger sized basalt gravel as well to obtain larger speckles.


The bowl below is Laguna half and half with 150 gm basalt dust (20 mesh) in 1000 gm premixed clay body.  Clear glaze on 1/3, oatmeal glaze on 1/3 and raw clay on the rest; fired to cone 6 oxidation.


Good luck to you,



Attached Thumbnails

  • scoria.jpg

#58343 Incorporating Metals Into Ceramic Sculpture

Posted by jrgpots on 11 May 2014 - 08:02 PM

A new specie of plant called Rinora niccolifea, was recently discovered in The Philippines. It accumulates up to 18,000 ppm of nickle in its leaves.  How would you like to make an ash glaze from this plant's leaves?

                                                            Ref  Phytokeys 2014; 37.7136   (just published this month)


Another plant is S. America accumulates gold in its leaves.  Miners look for the tree so they can process the gold-laden soil beneath.  I don't remember the source of this info.  Nor do I know if the plant grows in gold rich soils or if it accumulates and concentrates it; and in the process increase the gold concentration in the soil.  


Who said  "gold doesn't grow on tree?"


I understand this is "off-topic" a bit.  But it is a new twist on "incorporating metal in ceramics."



#58244 The Dangers Of Advice Without Experience

Posted by jrgpots on 09 May 2014 - 10:41 AM

For what it is worth...There is another active thread on the forum about dry skin caused by clay, glaze, etc. Biglou made an interesting observation. There are M.D.s on the forum, yet none have given their advise about ecczema, psoriasis, or contact dermatitis therapies as they relate to ceramics.

I am a praticing M.D. who treats these condition on a regular basis. Before I could diagnose I would need to gather a better history, view the lesions and review med usage, etc. The forum may not be the best place to do this.

BUT, It is a great place to take a history of ceramic problems, view pictures of the problem areas, review glaze usage and application, and diagnose/discuss remedies to the problems.

I appeciate and thank the "Clay Doctors" of this forum for sharing wthout restraint.