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Bentonite...to Blunge Or Not To Blunge.....

making clay again

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#1 Biglou13

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Posted 13 September 2013 - 07:12 PM

that is the question.....

 

Whether 'tis Nobler in the mind to blunge bentonite..... (mix in hot water and with hand blender in to more water..... sit over night)

 

im making clay with some bentonite,    im using the paint mixer and 5 gal bucket technique

 

i blunged the first batch,    but im also told it isint necessary   just mix well dry ingredients, then mix well wet and dry.

 

what say you?


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#2 TJR

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Posted 13 September 2013 - 07:32 PM

Verily, I say to thee...

Mix bentonite in water first, then add to your dry or wet mixture.

IT is possible to just add it to the dry materials, mix them dry and add water.

The first method is preferable for avoiding lumps.

I add 3% bent. to all my glazes to prevent settling.

TJR.



#3 bciskepottery

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Posted 13 September 2013 - 08:37 PM

Which brings up the larger question, whether 'tis nobler (or preferable) in the glaze kitchen to measure and mix your dry ingredients and then add water, or to put water in your bucket and add the measured dry ingredients? 

 

And, when adding dry ingredients to an already mixed bucket of glaze, should you mix said dry ingredients (e.g,, Veegum, bentonite) with water and then add or just add them dry?



#4 jrgpots

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Posted 13 September 2013 - 10:01 PM

It's kind of like making gravy.  Mix up the dry ingredients in a small cup of water, getting all the lumps out.  Then mix the cup's content into the premixed glaze.

 

Has anyone mixed up a soln of bentinite with a known specific gravity (of say 1.5) and added that solution to a glaze.  In other words, one could mix a known mass of bentinite in a 1000 ml volume of water water a measure that specific gravity.  He could then make up a large volume of bentinite to that same specific gravity and calculate the volume of the bentinite soln needed to correspont to  3% of any future glaze volume.

 

I was just thinking about storing this  bentinite soln in a sealed container for easy mixing into glazes, soln to soln without dry mixing.

 

 

Any thoughts?

 

Jed



#5 Mark C.

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Posted 14 September 2013 - 12:10 AM

I usually just toss it in with other dry ingredients and mix it with the 5 gallon mixer.

I use a blender/osterizier in the glaze shop to mix things like zinc ox-and other that do not sieve well-you could beat it with that small blender in warm water then pour into batch.

This tool is also great at small glaze tests.

Mark


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#6 oldlady

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Posted 14 September 2013 - 10:18 AM

i have to think in simple terms and pictures. this is how i think of it all. if bentonite gets wet, it gels.  if the tiny dry bentonite bits get separated by the tiny bits of other dry ingredients they cannot get close enough to each other to create a gel. that is why it works to mix dry bentonite into other ingredients, keep those little gang members from forming a mob and any way you work will be ok.

 

getting them hot and wet disperses them so they cannot gel and this works also.


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#7 TJR

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Posted 14 September 2013 - 10:36 AM

Which brings up the larger question, whether 'tis nobler (or preferable) in the glaze kitchen to measure and mix your dry ingredients and then add water, or to put water in your bucket and add the measured dry ingredients? 

 

And, when adding dry ingredients to an already mixed bucket of glaze, should you mix said dry ingredients (e.g,, Veegum, bentonite) with water and then add or just add them dry?

bcisk;

You should not be throwing dry bentonite into a wet glaze. This will cause the bentonite to gum up and then you will have difficulty sieving. If you have throw it into an already mixed glaze, decant some of the surface water before you mix up the glaze. Then mix your bentonite in warm water, and add to the glaze. You may then either add back some of the water you previously removed, or not.

TJR.



#8 Biglou13

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Posted 14 September 2013 - 09:04 PM

My first blunge.....1 gal water boiled bentonite mixed in with hand blender, Thus added to 2 ore gallons, mixed blender let sit overnight. In am it was all a gel.

The clay was a bit buttery, sticky, finicky, possibly thixotropic (not sure if that's correct use), ( felt good after wedge but soft and flimsy when made, pulled or pinched, walls tended to be floppy until drier).

I'm hypothesizing (guessing) that original recipe was dry mixed and blunging increases the plasticity. Original recipe has 5% bentonite.

There bentonite ratio to kaolin is 1: 7. ( Digital fire states 1:10 ) (http://digitalfire.c...tonite_106.html) the clay body also has about 14% om 4 also adding plasticity.

Has any one experienced an increase in plasticity more so when blunged, vs dry mixed.?

I'm going to reduce bentonite by 25% . Unless other wise advised?

I used 300 screen silica, would this add to the over plasticity?
Caution big brother is watching.
The beige is blinding!!!!!!
The middle of the road is boring

The true sign of intelligence is not knowledge but imagination.
-Albert Einstein

#9 JBaymore

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Posted 14 September 2013 - 09:27 PM

Wet mixing of clay bodies and then extracting the excess water always increases the plasticity (in the early stages) of the body because ALL of the clay particles are coated with a layer of water.... rather than just some of them.

 

Best way to make clay.

 

best,

 

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


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