Cone 6 slip casting recipe

[Bam2015]

Hi All,

I have been using Laguna porcelain and stoneware pouring slip and now considering trying to make my own. I've found a few recipes on line, but wonder if anyone has any recipes that they like,  and if they find it worth it to make pouring slip rather than purchasing.

Thank you,

Betty

[PeterH]

You might also want to look at dry ready-mixes.

This sort of thing
https://www.potterycrafts.co.uk/Products/pottery-powdered-clays/P3103
Limoges Porcelain Casting Slip Recipe
P3103 Limoges Porcelain Clay - 50kg
Water - 18.5lt
P3342 Soda Ash - nil
P3344Soda Sil - nil
Deflocculants are added in the spray drying of this clay so it is not necessary to add them.

[Jeff Longtin]

Good Morning Betty,

I'm sorry I missed this. (Its been a busy last few weeks.)

A website called "Claybucket.com" has some good recipes. My favorite is:

Water                     10000 gms

Darvan #7             80 gms

Bentonite              100 gms

Grolleg Kaolin     11000 gms

Nep Sye                   4600 gms

Silica                          4400 gms

When mixing Bentonite its usually best to mix it with the dry material first to break it down. If you just add it to water it will clump up horribly.

Start by adding the Darvan to the water first. Then I add the dry ingredients. It's been awhile but I think I add the Nep Sye and Silica first and then the Grolleg Kaolin. As the slip will thicken quickly I find it best to add the clay a little at a time. 

I hope this helps.

 

 

[Bam2015]

Peter and Jeff, thank you for your responses.

Peter, thank you for the suggestion of a dry clay mix. I will Google to see what is available in the US. 

Jeff, I am going to try that recipe this winter. I found several recipes on line, but would prefer to try a recipe that someone on this forum recommends. I'll let you know how it turns out. Will probably wait until the new year to try it out. 

Betty

[Mark C.]

(I will Google to see what is available in the US) 

all of those ingredients are in the US no need to check that

[Jeff Longtin]

Another recipe that I have used is one published by Ceramics Monthly in their 1982 edition. In that edition they profiled Dorothy Hafner, a potter in New York. I tested out the recipe and used it for a year, or two, until I realized my clear glaze was crazing on it.

OM4    10

EPK      20

#6           20

Nep Sye   25

Flint           25

The original recipe calls for 350 cc N brand Sodium Silicate and 50 grams Soda ash  (to 500 lbs powder?) but I found the Darvan #7 proportion I listed above to work equally well.

For kicks I mixed up a small batch last year and was surprised how nicely it casts and how white it is.

 

[Bam2015]

Thank you for the recipe Jeff.  Did you ever find a glaze to fit?

Betty

[Jeff Longtin]

Hey Betty,

I didn't. I think I tried her cone 7 recipe but went with something else instead.

I had Lithium Carbonate, in my studio, for many years. I do believe I used a recipe, with it, in it. Once Lithium was viewed as toxic I decided to abandon that recipe and turned to premix glazes instead.

 

[Harold Roberts]

Hi Betty,

For a couple of decades I have used a cone 6 white firing slip that I have never had trouble with. No cracking or warping or glaze fit problems.

I always made 80 lbs in two 5 gal. buckets so this is the recipe,

Water ............... 16 to 18 lbs with 5 Tbs Davan #7

Ball clay .............3 lbs

EPK ..................15 lbs

Flint 325 ........10 lbs

Neph Sy ......... 12 lbs

[Harold Roberts]

Hi Betty,

After looking at my most recent notes I realize I use Pioneer Kaolin instead of EPK. For many years I used EPK and the reason to use Pioneer was to get a whiter fired look.

Another trick I use if the water is hard is to add a teaspoon of household lye. It will make the slip much more fluid. Also you can use up to 20 lbs of water.

16 lbs equals 2 gallons if you prefer to measure it that way and just add no more than 4 more pints.