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Slip Settling


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#1 Mossyrock

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Posted 20 July 2012 - 10:32 AM

I work in low fire to cone 6 oxidation and have a white slip recipe that works well for both. The problem is that within a few days, the slip settles to the bottom of the container into a clump (for lack of a better word) and it takes a lot of time and effort to put it back into a nice usable suspension. Is there anything I can add that will keep this from happening or is that just a characteristic of slip? Here's the recipe:

6 Tile 1500 g
OM4 Ball Clay 1000 g
Custer Feldspar 1250 g
Silica 1250 g
Zircopax 300 g

I mix the dry ingredients and keep in an airtight container. When I need to mix a batch of slip, I weigh out 1000 g of the dry mix, add 4 tsp. Sodium Silicate, then add water and sieve several times. It's great until I don't use it for several days. Thanks for any help.
Brenda Moore
Mossy Rock Creations
High Point, NC

#2 Mark C.

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Posted 20 July 2012 - 11:12 AM

Thats a lot of clay to keep up.
I have had super results with a product called Magma sold at Big Ceramic store.com in glaze use I'm sure it would help in your slip-The key to slip casting is long amounts of time power mixing before use.If its just slip for pots try the magma.
Mark
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#3 neilestrick

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Posted 20 July 2012 - 11:13 AM

Are you casting the slip, or decorating with it?
Neil Estrick
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#4 Mossyrock

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Posted 20 July 2012 - 04:01 PM

I am decorating with it, not casting. And I am brushing it on the pots. It takes several days for the slip to settle to the bottom and become unusable until it is stirred, stirred, stirred.....and then stirred again. Thanks again for any help.
Brenda Moore
Mossy Rock Creations
High Point, NC

#5 Mark C.

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Posted 20 July 2012 - 04:44 PM

I am decorating with it, not casting. And I am brushing it on the pots. It takes several days for the slip to settle to the bottom and become unusable until it is stirred, stirred, stirred.....and then stirred again. Thanks again for any help.


Try the Magma it keeps bricks in suspension.
PS use only a very small amount and mix it in hot water.

Mark
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#6 Lendar

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Posted 20 July 2012 - 04:56 PM

I have also used Magma and I was extremely satisfied.

#7 Mossyrock

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Posted 20 July 2012 - 06:36 PM

So I can use the Magma in glazes that settle 'too much' as well as slip? Thanks....I'll order some and give it a try.
Brenda Moore
Mossy Rock Creations
High Point, NC

#8 ~janie

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Posted 21 July 2012 - 06:25 PM

Also.....you can dissolve a small amount of epsom salts in a small amount of very hot water and pour the water into the slip after it has set up, but before you stir it. Let it sit for awhile and then stir. You may need a little more, but try to stir it first to be sure. Once it is usable again, it will not set up like that again.

Before I get in trouble, let me say for sure that this works fantastic for glazes. However, I don't see any reason it wouldn't work as well with slip. I would sure use it on mine, just to make sure. Does anyone else know anything about this?

#9 Mossyrock

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Posted 23 July 2012 - 07:01 AM

Also.....you can dissolve a small amount of epsom salts in a small amount of very hot water and pour the water into the slip after it has set up, but before you stir it. Let it sit for awhile and then stir. You may need a little more, but try to stir it first to be sure. Once it is usable again, it will not set up like that again.

Before I get in trouble, let me say for sure that this works fantastic for glazes. However, I don't see any reason it wouldn't work as well with slip. I would sure use it on mine, just to make sure. Does anyone else know anything about this?


I'll give this a try Janie. It's not like I will ruin a large batch if it doesn't work. If I've got about 5 cups of slip, about how much Epsom salts would you use? You said a small amount.....I'm thinking a teaspoon? I'm still going to order the Magma, but in the meantime, I'll give this a shot.
Brenda Moore
Mossy Rock Creations
High Point, NC

#10 Edith Marie

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Posted 23 July 2012 - 10:07 AM

Have you tried using a blender to re-mix your slip? Used blenders can be found at garage sales and work well with making glazes.

#11 Mark C.

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Posted 23 July 2012 - 11:45 AM

For decorating only I would try the epson salts<div>for 5 cups which is a very small amount-use hot water to dissolve and a tablespoon of salts.
This may help.
The thrift store blender I us e all the time in my studio- as well for glaze making</div><div>Slip settles and will need mixing-so get a small mixer for a hand held drill for your slip.
<div>Mark</div>
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www.liscomhillpottery.com

#12 ~janie

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Posted 23 July 2012 - 12:11 PM

What Mark said. About a TBSP epsom salts in about 1/4 cup very hot water. A TBSP would also work for a larger amount, too.

I went to yard sales until I found a blender, a juicer, and an electric skillet (for melting wax). Total cost was less than $10.00.



#13 JLowes

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Posted 23 July 2012 - 12:30 PM

Okay ~janie,

At first I thought of one of those "which word doesn't fit?" type of puzzles, with blender, juicer and electric skillet; juicer being the one that didn't seem to fit in the context (to non-clay folks, the answer would be all of them fit ...in the kitchen.) So what kind of clay magic can we do with a juicer? Is this a manual or electric juicer? I may have to be on the lookout for one of these, or if it is a manual juicer, I have my next project.

John

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#14 TJR

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Posted 23 July 2012 - 12:37 PM

O.K.;
You are going to laugh. Mark has accused me of being the guy who talks the airplane down after the pilot has had a heart attack. Here goes;
Bear in mind that I am Canadian, and we are a helpful bunch. Don't hold it against me.
I looked at your slip formula and saw that you have WAY too much silica in there and that is what is causing it to settle.This may take me a moment to explain, but bear with me.
1.Your formula-
Tile 6 1500
Ball 1000
Custer 1250
Silica1 1 250
Zircopax 300

2.I dropped off the zeroes,leaving you with
Tile 6 150
Ball 100
Custer125
Silica 125

Total 500
3. I left out the zircopax for the moment as it is there to make the slip whiter.
4. If you divide each of your four materials by your total of 500 grams, this is what you get;
Tile .30
Ball.20
Custer.25
Silica .25
Total 100
add Zirco at .6

If you look at the percentages, you have 25% silica, and 25% Custer, both very heavy materials.
So, I dropped the silica down to 10% and recalculated your recipe for you. I have not tested this, but you should make a 100 gram batch and see if it settles.
Tom's White Slip
Tile 6 35
Ball 24
Custer29
Silica 12
Total 100
Zirco 6

This should work better for you.LET ME KNOW HOW IT GOES.oops, caps lock on again.
TJR.

#15 Mark C.

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Posted 23 July 2012 - 01:31 PM

TRJ
You really did your homework on this one-I think she will be able to land it now

JLowes
I have no idea about the juicier in the studio?

If your feet hurt soak them in hot water with epsom salt-old timers trick

Mark
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#16 TJR

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Posted 23 July 2012 - 03:47 PM

TRJ
You really did your homework on this one-I think she will be able to land it now

JLowes
I have no idea about the juicier in the studio?

If your feet hurt soak them in hot water with epsom salt-old timers trick

Mark


Mark;
I actually had to get up off my chair and get a calculator for this one. Hope she lands without a scratch.
TJR.

#17 ~janie

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Posted 23 July 2012 - 05:21 PM

The juicer is a handheld device for mashing up fruit for drinks. It reminds me of an upside down helicopter, in that the blade is on the bottom and is plunged into a cup, glass, or pot of some sort to reduce the fruit to a smoothie consistancy. They are about $12.00 new at WalMart, but I found mine at a yard sale for $1.00. The lady told me she got it for her birthday, and it made her mad then and does every time she looked at it, so decided to get rid of it. LOL

TJR, I think you are right. I think I might try this myself.

#18 TJR

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Posted 23 July 2012 - 05:35 PM

The juicer is a handheld device for mashing up fruit for drinks. It reminds me of an upside down helicopter, in that the blade is on the bottom and is plunged into a cup, glass, or pot of some sort to reduce the fruit to a smoothie consistancy. They are about $12.00 new at WalMart, but I found mine at a yard sale for $1.00. The lady told me she got it for her birthday, and it made her mad then and does every time she looked at it, so decided to get rid of it. LOL

TJR, I think you are right. I think I might try this myself.


Janie;
Here is my analogy. If I have a pain in my hip, I go to the doctor.He/she looks at the PROBLEM, rather than masking it with pain killers. Yes, you can buy juicers at Walmart for $12.00, or $1.00 at the garage sale, and you can buy fry pans and toaster ovens as well. But ultimately you have a slip with far too much sand in it.It will still settle. You can throw Epsom salts at it and change the electrolytes, and I can put a band-aide on my hip. Am I going to do that? No.
Today is the anniversary of the Gimli Glider. The pilot glided a huge plane with 65 passengers on board, completely empty of fuel. There was an article in the Globe and mail today.
TJR.

#19 Lucille Oka

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Posted 23 July 2012 - 09:10 PM

The device is called an 'immersion blender'. I am thinking about getting one. I'll make sorbet or a frappe once or twice but then transfer its use to clay and glazes.
John 3:16
"For God so loved the world that He gave His only begotten Son, that whosoever believeth in Him should not perish but have everlasting life".

#20 BeckyH

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Posted 23 July 2012 - 10:02 PM

Any slip will settle over time. We use a cordless power drill with a paint mixer to resuspend the particles in our slip every time we get ready to cast. We also use a commercial defloculant, adding as necessary to get the consistency we like.
Remember-
If you aren't part of the solution, you're part of the precipitate!!




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