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Sodium silicate


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#1 Nelly

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Posted 06 December 2012 - 07:52 PM

Dear All,

Today I used sodium silicate on the outside of a stone ware pot I threw. I was able to create the nice cracks on the outside of my bowl with this substance.

After I finished with the sodium silicate, rather than put what I considered the contaminated remainder of this solution back in the jar (a few tablespoons), I threw it into my slop bucket. This slop bucket contains clay I hope to recycle.

I do know Sodium Silicate is powerful stuff. Will it affect my recycle bucket of clay in any detrimental way??

In terms of a percent think of two table spoons of SS in a kitty litter container size of scraps (i.e., 1 1/2 gallons).

I know there are many factors involved with this question (i.e., stoneware body, amount of water, amount of SS etc.).

My worry is that the clay if thrown will melt in the kiln?? Is this a possibility and should I simply throw out the whole mess of clay??

It is not a big deal if I throw it out but I will use it if no-one has tried this experiment and found it did not work as planned.

Has anyone thrown their excess SS in their slop water and recycled this clay without problem in firing?

Nelly

#2 JBaymore

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Posted 06 December 2012 - 08:16 PM

Likely it is going to have an impact. We are back to the "test" comment. ;)src="http://ceramicartsda...ault/wink.gif">

I use this sodium silicate technique a lot on my work (images about this work in the new book
"The Appreciations and Collections of Modern and Contemporary Ceramic Art"by Guangzhen Zhou, Jiangsu Fine Art Publishing,China).

When I work with the sodium silicate on the outside of forms, I do not reclaim any of the scraps that I accumulate in the process. If I screw up a whole piece as I am expanding it, it gets crunched up and the whole piece of clay gets sent to the "landfill bin". The sodium silicate in the reclaim adversely affects the properties of the plastic clay body.

I'd suggest trying to keep the matrerial out of your plastic clay supply as much as is possible. I've never been happy when it gets into things....... you might not either. But of course, "your mileage may vary, not valid in all states, terms and conditions may apply, may not be combined with any other discounts."

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#3 Nelly

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Posted 06 December 2012 - 08:24 PM

Likely it is going to have an impact. We are back to the "test" comment. ;)src="http://ceramicartsda...ault/wink.gif">

I use this sodium silicate technique a lot on my work (images about this work in the new book
"The Appreciations and Collections of Modern and Contemporary Ceramic Art"by Guangzhen Zhou, Jiangsu Fine Art Publishing,China).

When I work with the sodium silicate on the outside of forms, I do not reclaim any of the scraps that I accumulate in the process. If I screw up a whole piece as I am expanding it, it gets crunched up and the whole piece of clay gets sent to the "landfill bin". The sodium silicate in the reclaim adversely affects the properties of the plastic clay body.

I'd suggest trying to keep the matrerial out of your plastic clay supply as much as is possible. I've never been happy when it gets into things....... you might not either. But of course, "your mileage may vary, not valid in all states, terms and conditions may apply, may not be combined with any other discounts."

best,

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


Dear John,

Enough said. I will throw it out. It isn't enough and I do not want to play with clay that is not going to recycle well or cause damage to the kiln shelf. I will simply throw it out.

I have seen this stuff cause darkening of wheel heads so I know it is powerful stuff. My slop bucket will be ditched tonight.

No need to keep this up. You answered my question.

THANK YOU.

Nelly

#4 Brian Reed

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Posted 08 December 2012 - 12:59 PM

I also throw out any clay that is contaminated with Sodium Silicate. Also the left over SS that has some clay residue in it does not need to be thrown out. I have a small container that I have my SS in and as long as it is not contaminated with an oxide like iron then the slighly off color SS does no effect anything. I would not throw out the left over SS.
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#5 Nelly

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Posted 08 December 2012 - 01:31 PM

I also throw out any clay that is contaminated with Sodium Silicate. Also the left over SS that has some clay residue in it does not need to be thrown out. I have a small container that I have my SS in and as long as it is not contaminated with an oxide like iron then the slighly off color SS does no effect anything. I would not throw out the left over SS.


Dear Brian,

Thank you for responding. The SS was not contaminated with any oxide so I guess I could have kept it?? I just worried about contamination given that I had dipped my brush into the solution several times. Thank you for letting me know also that you throw out any clay with the SS in it. After reading the previous post I did in fact throw it out--lock stock and barrel. Gone. The last thing I need is to be spending hours trying to wedge up some clay that will never be the same with the addition of this chemical. Thank you again for responding.

Nelly

#6 drmyrtle

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Posted 27 February 2016 - 06:13 PM

Sooo... Could I bring this topic back up? The people who use the recycled, pugged clay at my current studio are abruptly having a huge problem with "short"/ low plasticity in the reclaim. This wasn't a problem last fall at all, but now I see friends struggling with basic handle pulling and even well-thrown pots "splitting" on the outside after the pot has been thrown. I tried to pull some handles myself and "no go", unlike a handle or 20 made from 'new' boxed clay. I even wet mixed 50% porcelain + 50% their reclaim, and couldn't pull it worth a darn.

 

I found out today that late last fall, one of the instructors had told students that they could put all of their substandard terra sig projects right into the reclaim bucket, along with any terra sig liquid scraps left over. I also confirmed that their sig recipe has sodium silicate in it. For those who know, don't you think that their entire reclaim bucket has been contaminated with a large enough portion of sodium silicate that all of the clay is contaminated and ruined. (Well, ruined if you think permanent defloculation is ruined.)

 

If you have opinion, could you post such that I might bring in your thoughts? The students were afraid to go against the instructors instructions, and I'm thinkin' the whole batch is wasted because of the contamination. What should be done with the reclaim now? Can it be used even for hand-building?



#7 Mark C.

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Posted 27 February 2016 - 06:23 PM

My guess is that clay is toast-its plasticity is screwed up.

Seems clear no sodium silicate in reclaim should be the rule.

The clay will not throw well anymore.

not much of a hand builder so I'll let other say about that.


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#8 Babs

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Posted 27 February 2016 - 10:36 PM

Yeh but some clays  get short on the reclaim anyway.

Throw away the stuff you've messed up or use as  base for slips but 11/2 gal may last a long time......

I guess you would have heat gunned and hardened some what the SS so tossing out  the scraps from the projects  makes sense.



#9 MatthewV

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Posted 28 February 2016 - 02:01 AM

First I would check the vacuum of the pug mill. If that is all fine, well...


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#10 High Bridge Pottery

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Posted 28 February 2016 - 06:09 AM

Nobody does slip casting or uses coloured slips? I would think it would be ok for that. 


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#11 Pieter Mostert

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Posted 29 February 2016 - 03:23 PM

I wonder if adding Epsom salts (dissolved in water) would improve the plasticity of clay contaminated with sodium silicate. I've found that this works for clay that's been deflocculated with sodium polyacrylate (aka Alcosperse aka Darvan).



#12 drmyrtle

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Posted 29 February 2016 - 04:09 PM

Well, I'll give the Epsom salts a try this week--good suggestion. It will be an interesting experiment, although I doubt many other people would be interested.

 

Just to give people an idea, this is a 70 gal bucket full of clay. It's a lot of clay, and I think they'd be better off to pitch it and start anew. I also wonder how much the silica is attached to the bucket: perhaps the bucket should be pitched for good measure? I know that you can't actually "wash" silicate off because it isn't soluble with most detergents. Mostly when we wash it we're just diluting it to very small amounts.



#13 ronfire

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Posted 01 March 2016 - 10:03 AM

Would also be a problem if you use magic water to attach handles to your pieces then recycle them? The Magic Water contains Sodium Silicate.






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