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Member Since 15 Mar 2013
Offline Last Active May 20 2015 08:27 PM

#79185 Iron Speckles

Posted by jrgpots on 12 April 2015 - 08:50 PM

I remember an organic chem lab I had to take. I made vanilla crystals which normally are large and white. Mine were small and green. The size came from being too much in a hurry. I can buy that....But the green color? The mass spectrometer showed copper in the mix. It turned out that I used an old chrome plated scoop to measure ans stir my soln. The chrome had worn off and the copper metal was exposed to the acidic solution. The result...green crystals.

It comes to mind every time I have an unusual outcome. When it comes to glaze making, it is ever present on my mind.

Just reflections.


#78822 Iron Speckles

Posted by jrgpots on 07 April 2015 - 11:08 PM

Wallastonite can have many impurities,such as garnet as mentioned in digitalfire. Could this be the source of your specks? I would try a different source of this ingredient.

That's my guess.

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#77632 New Copper Carb A Way Different Color!

Posted by jrgpots on 18 March 2015 - 11:52 PM

Trying to remember my geology, Malachite, Cu2Co3(OH)2, is a mint green and azurite,Cu3(CO3)2(OH)2 is bright blue. Both are forms of copper carbonate. The differences in color comes from the differences in % of each of these two. Of the two, azurite has more Cu per molecular weight. That would mean that the mint green color has more Cu by weight. It would make sense that glaze colors would change as well.

I went out to the garage and found this ore sample. The light green is malachite while the deeper blue is azurite. Both exist in the same ore sample.

Like always, test, test, test.


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#76031 *gasp* Handle Sacrilege!

Posted by jrgpots on 24 February 2015 - 01:38 AM

Also, another reason I enjoy pulled handles, is because I get to demonstrate it straight-faced, to a group of teenagers, while watching them try to not laugh...[/quote]

If you wanted to make them laugh, cover it with a condom to dry. You could Segway into clay shrinkage at the same time....lol

#75164 Community Challenge #1

Posted by jrgpots on 10 February 2015 - 11:07 PM

I have thought about making an "hot air balloon" using doylies soaked in slip and draped over balloon, allowed to dry, then fired. I've never done this, but it sounds fun.


#74728 Icing For Ceramic Gingerbread

Posted by jrgpots on 03 February 2015 - 12:31 AM

I've been out for quite some time. But, I wanted to post where my gingerbread church stands. It is drying slowly. I need to pipe the ridges and corners. In the next two weeks, I will finish the piping and corners. I need to make paper slip with magic water to repair the cracks before firing. Once Fired, I will add shingles.


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#67951 I'm Looking For Old Talc-Do You Have Any?

Posted by jrgpots on 16 October 2014 - 11:26 PM

Imagines Mark meeting a talc dealer on a street corner, exchanging cash baggies of sweet, sweet vintage talc...

So,....with what do you cut talc?


#67310 Icing For Ceramic Gingerbread

Posted by jrgpots on 05 October 2014 - 07:58 PM

I used to own a bakery and learned to decorate cakes for birthdays and weddings. A pipping bag will work just as well with a heavy slip and will allow you to make any type of decoration that is used on a cake. There are all kinds of tips you can use.
Just practice on a plaster batte and scoop the slip back into the container when you are finished. Look up the pipping techniques on  u-tube and in a couple of hours you will be up and running.

Tomorrow I'll get some decorating tips from the hobby shop and practice to get the right consistancy of the paper slip. It will take me longer than a few hours to be good at piping. I will try making canes too. Watch out Chris Campbell, here I come......lol


#66730 Used Car, I Mean Kiln Shopping

Posted by jrgpots on 27 September 2014 - 12:33 AM

I am flattered that you had followed my thread....I know of an updraft olympic 10 cubic kiln that has been for sale for $750 OBO for one year.... it has been sitting for a while. So, If he is in such a hurry, he may end up giving the things away. They are not that easy to unload if they are not in working order.....So if they were free, would you take them?... What would be the cost to get them in working order?...And once restored, what would be their lifespan?

I recently drew up plans for a 12 cubic feet downdraft kiln with 9" walls. My estimate was $3000 for materials and about $1000 for power burners.


#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

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#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.