Making Slip?

[mdobay]

Sorry if this has been cover a million times, but didn't find the answer in my search.  Ok, I am going to make some colored slip to use on some of my work. My plan was to crush up some dried out clay in to a power, add a percentage stain and add water. Assuming this is the right approach, do I, should I also include some sodium silicate to the mix?   

Thanks in advance for any input.

[Evelyne Schoenmann]

mdobay: welcome to the forum! I never add sodium silicate. I use it only (pure) to put onto a wheel thrown piece to get crackles when bellying out the cylinder. Or you use sodium silicate to produce magical water for instance.

Slip: soak the clay in water, add color or stain, mix it with a hand mixer, let it set to a yoghurt consistency and you have your slip. I don't crush up dry clay to powder before adding to water. I just toss scraps into water and let it set over night. Then either add water if it is too thick, or empty out some of the water when too thin (and let it set again). You want the slip to be like yoghurt or thick cream.

 

Will we see some finished slip covered pieces from you here?

 

Evelyne

[mdobay]

Thanks for the advice and quick reply Evelyne.   Yes I will post pictures if I produce anything I really like, which is rare

[bciskepottery]

I've made slip using both methods . . . drying out clay first, and slaking down wet clay.  For coloring your slip, drying the clay body allows you more control in making the same slip as you are using dry measurements.  So if repeatability is in your plans, that is a good approach.  Mostly I dry porcelain to use for my slips with color as the porcelain gives you a white clay base and, in my opinion, bright color response from the stains.  Stoneware bodies can have ingredients in them (that fire to gray, brown, red, etc.) that can affect your color outcome.  Mixing with water works fine. 

[mdobay]

Thanks BC,  I will using B-Mix to make the slip and to throw the forms with. At present B-Mix is my favorite to work with. The studio that I throw at only fires to cone 6 and my understanding is you need cone 10 to fire porcelain, so B gets me pretty close.

[neilestrick]

Regular B-Mix is cone 10, but they make a cone 6 version. There are also cone 6 porcelain bodies.

[bciskepottery]

I use Highwater's Helio porcelain (cone 10) for making my colored slips . . . and I fire to cone 6 (generally Highwater's Little Loafers, a cone 6 stoneware).  The slip application is thin; I've had no problems with the slip affecting vitrification, etc.