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Marcia Selsor

Sodium Silicate Cracked Surfaces On Thrown Pottery

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I've been using this technique for years and YEARS now.  I too thought is was a pretty common approach like you mentioned in the other thread (that you built this separate topic off of), Marcia.  I've been using it so long that I cannot remember where the heck I first heard about it..... but it was way "back in the day"....probably in the early 70's.

 

But I was doing a demo of my work and how I handle that water glass stuff at Tokyo National University of Fine Arts a couple of years ago, and a lot of the international folks there had not seen it before.  Long story short...... that demo got photoed ... and resulted in me getting some stuff published in a book in China about it this past year.

 

I use it with pretty heavily altered bodies a lot.  Makes the effects very pronounced. For the weay I use it, it is all about the time you leave the material on the work before stretching.  I don't use a rib on the inside... fingers only; gives me more immediate tactile feedback as to what the clay is doing.   I also do not use a heat gun or blow dryer or torch on the outside.

 

Here's one in my gallery :  http://community.ceramicartsdaily.org/gallery/image/3035-yakishime-gourd-shape-vase/

 

best,

 

................john

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It is fun and everything but gets old really fast.

You are way better of using glazes and porcelain slip to get natural cracked mud texture. I think it's more enjoyable and way less controlled than sodium silicate.

 

Do not get me wrong, this is a cool technique and a very interesting experiment. Use at least once, to find out :) Use more, if it keeps surprising you.

 

(off topic thoughts) I like Hsin-Chuen Lin videos. This guy has contributed massive amount of truly educational stuff to potters community around the world. So, local big shots and international educators, where are your videos ;) <- joke, relax! NOT!

 

But for some reason, when I watch his videos, I always start thinking at the lst part of the videos "Stop, stop now, please stop! Do not touch that @(}$^&&* piece any more..." (usually about 6-5 min before he finishes)

 

I wish I had that good throwing technique as Mr.Lin has but I think he "licks" the life out of those forms in last 5-6 video minutes and it happens almost every time. (if you are reading, sorry for being so blunt)

 

One of the hardest things in ceramics is to stop before you finish off (kill) your piece of for good.

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I've been using this technique for years and YEARS now.  I too thought is was a pretty common approach like you mentioned in the other thread (that you built this separate topic off of), Marcia.  I've been using it so long that I cannot remember where the heck I first heard about it..... but it was way "back in the day"....probably in the early 70's.

 

But I was doing a demo of my work and how I handle that water glass stuff at Tokyo National University of Fine Arts a couple of years ago, and a lot of the international folks there had not seen it before.  Long story short...... that demo got photoed ... and resulted in me getting some stuff published in a book in China about it this past year.

 

I use it with pretty heavily altered bodies a lot.  Makes the effects very pronounced. For the weay I use it, it is all about the time you leave the material on the work before stretching.  I don't use a rib on the inside... fingers only; gives me more immediate tactile feedback as to what the clay is doing.   I also do not use a heat gun or blow dryer or torch on the outside.

 

Here's one in my gallery :  http://community.ceramicartsdaily.org/gallery/image/3035-yakishime-gourd-shape-vase/

 

best,

 

................john

I know. It has been around forever. I just used it because I wanted to see it in the obvara firing because texture seemed to work in that process.  I just thought I'd show our group that  it is nothing new.

Nice pots , John!

Marcia

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It is fun and everything but gets old really fast.

You are way better of using glazes and porcelain slip to get natural cracked mud texture. I think it's more enjoyable and way less controlled than sodium silicate.

 

Do not get me wrong, this is a cool technique and a very interesting experiment. Use at least once, to find out :) Use more, if it keeps surprising you.

 

(off topic thoughts) I like Hsin-Chuen Lin videos. This guy has contributed massive amount of truly educational stuff to potters community around the world. So, local big shots and international educators, where are your videos ;) <- joke, relax! NOT!

 

But for some reason, when I watch his videos, I always start thinking at the lst part of the videos "Stop, stop now, please stop! Do not touch that @(}$^&&* piece any more..." (usually about 6-5 min before he finishes)

 

I wish I had that good throwing technique as Mr.Lin has but I think he "licks" the life out of those forms in last 5-6 video minutes and it happens almost every time. (if you are reading, sorry for being so blunt)

 

One of the hardest things in ceramics is to stop before you finish off (kill) your piece of for good.

Hi Mart or Martina "ain't telling" I have an Alternative  Firing dvd for teachers  coming out in March.Prior to availability of you tubes, fr the past 40 years I have published 30+ articles for newsletters and magazines authored one book and contributed to several others,  on all sorts of topics from clay techniques, forms,  to burners, kilns , etc.  I agree Hsin-Chuen Lin has done some great you-tubes and contributed to educating the clay community. There are many more sharing people out there, too. And many more teachers who share as well. I think you should share a bit more information about yourself before you start criticizing those who do share. "So, local big shots and international educators, where are your videos"   ;) <- joke, relax! NOT!

 

Marcia

JBaymore likes this

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As with most pottery techniques, it is a tool to be used when desired. Use it for a while or until you've worked through the possibilities then store it til next time. You might even forget some process until you see someone else using it and get the aha moment ... "I used to do that! Why did I stop?"

I hear potters say ... Oh, I'm not ever going to use that so I'm not going to bother learning it ... But it's amazing how often you end up wishing you had the options.

As to overworking pots ... the potter gets to say when it's finished ... not the audience, thank goodness ... Because speaking as a member of said peanut gallery, I have often been wrong about whether or not it was finished.

Rebekah Krieger likes this

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Been doing this off and on for a few years, most recently had an order for a set of mugs(still in the kiln) with the expanded exterior.  I really liked what I saw when I peeked and may be doing a few more for myself. 

 

Marcia, I have used this process for Obvara as well, although I haven't gotten the cracks as dark as I thought they'd get.  I started using the process for smoke firing for contrasting textures on black pieces.

 

Chad

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Marcia, you get an amazing cracking with this method. I get small cracks.. Do you apply a lot of layers of Sod. Sil. or is it your body that allows this amazing cracking.. doesn't read too well but hope you get what I am trying to ask. :)  You're applying the silicate as you finish drawing up the cylinder or do you allow a time lapse?

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Been doing this off and on for a few years, most recently had an order for a set of mugs(still in the kiln) with the expanded exterior.  I really liked what I saw when I peeked and may be doing a few more for myself. 

 

Marcia, I have used this process for Obvara as well, although I haven't gotten the cracks as dark as I thought they'd get.  I started using the process for smoke firing for contrasting textures on black pieces.

 

Chad

Chad,

I'd love to see them. Your you tube is very informative.Do you have any in the gallery. I will check. Thanks for your info.

 

Marcia

 

Babs, 

I let the cylinder sit a while before adding the Sod. Silicate. One coat is enough. I don't want it to drip. 

I use a torch usually, but I also have used hair dryers and heat gun. All work.

 

Marcia

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Did you notice any difference in adherence of glazes to the sodium silicate surface after it was bisqued at Cone 05 or so?

Can we safely assume that sodium silicate burns out sufficiently not to interfere with oxides, glazes, etc.?

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Did you notice any difference in adherence of glazes to the sodium silicate surface after it was bisqued at Cone 05 or so?

Can we safely assume that sodium silicate burns out sufficiently not to interfere with oxides, glazes, etc.?

 

It has never interfered with glazes, at least for me..... but I DO see a light and subtle color variation in the areas treated with sodium silicate in cone 9,10,11,12,13,14 reduction firings, both gas and wood. Nothing totally dramatic...... but it is there. You are adding a sodium bearing compound to the clay surface....... water glass has a high sodium to silica ratio,....... so it will affect the fired surface slightly.

 

Technically it HAS to be affecting the bisque too.... but apparently not enough to change glaze application based upon the porosity of the clay.

 

best,

 

.........................john

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Marcia, here are a two photos we've done using the expanded sodium silicate....one Obvara and one blackware.  I might have to talk my 10 year old into running the video camera again.

 

MichaelP...I played around with various washes/glazes and have not had any trouble with products adhereing to the surface provide it was bisqued.

 

Chad

post-5885-0-37717100-1387052502_thumb.jpg

post-5885-0-28476100-1387052610_thumb.jpg

post-5885-0-37717100-1387052502_thumb.jpg

post-5885-0-28476100-1387052610_thumb.jpg

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Marcia, here are a two photos we've done using the expanded sodium silicate....one Obvara and one blackware.  I might have to talk my 10 year old into running the video camera again.

 

MichaelP...I played around with various washes/glazes and have not had any trouble with products adhereing to the surface provide it was bisqued.

 

Chad

I like them both. The black is dramatic with a feel of lava. The golden brown is warm and the cracks are very nice.

Marcia

Up in Smoke Pottery likes this

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I have used this method several times to good success! I do use a hair dryer to dry the sodium silicate on the cylinder before using my fingers to shape. I also have put iron oxide (on the 04bisque) in the textured cracks and wiped off before dipping in cone 6 glaze, sometimes waxing the texture sometimes letting the glaze cover then wiping off , letting the glaze also fill in the texture. I have also textured over the cracks with a texture wheel.

I really have fun with this method and get beautiful results each time. I would like to post pictures but I don't see the button!

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This is a really fun technique to use. Anything you do to the piece before applying the silicate will stay reasonably intact, so go nuts with carving and texture stamps and what not. If you chatter the pot while it is still wet, then go about the process normally, you can get a surface that looks like tree bark.

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