Making Slip

[saxpot]

I'm a beginning potter and have seen all kinds of interesting decorating ideas using slip. Is it easy to make? Or should I buy it? Any suggestions are appreciated.

[Marcia Selsor]

Start with using the slip from your clay body and adding colorants.

Marcia

[JLowes]

You can make it, and it is pretty easy. If you want a slip that matches the shrinkage of your clay perfectly, make slip from that clay. To read about making slip, this link will give you an idea of what's involved:

 

http://www.lagunaclay.com/support/art-of-slipmaking.php

 

It's actually much easier that it reads to be when you do this on a small scale, and we are not making casting slip. You can dry out your trimmings and save them to use, or process some of your clay in a blender, with water, and judge the consistency by eye as you adjust. The sodium silicate is probably the hardest part.

 

I have also used casting slip I purchased in a one gallon jug. If you buy it, make sure it is for the firing Cone you use.

[OOF!]

At the risk of killing yet another thread, I will chime in.

I agree with the above potters, to use the clay which you use to make your work. The advantages are that it is readily available, and will not present problems with shrinkage/fit.

I like to throw using a clay grogged with a 40 mesh mullite. I tried using it as a slip to brush over pots so that I would get a smoother surface to burnish. The grog presented a problem, as now seems obvious, it was never going to give me the smooth surface I wanted.

So I started to dry out my clay completely, slake it and then put the "slip" through a 100 mesh sieve, and I now get what I call "psuedo-sig," as it is so silky and smooth, and gives me a great surface.

So almost any clay can give you good slip, if you prep it right, I guess.

[Seasoned Warrior]

Since you are beginning you may wish to use tri-sodium phosphate as a deflocculant as opposed to buying sodium silicate. the tri-sodium phosphate is also known as TSP and is readily available in hardware and paint stores. You don't need much, percentually speaking. When I make up casting slip from local clays I have found that a one quater of a cup to 5 gallons of slip is more than adequate. The deflocculant aids in keeping the particles in suspension otherwise the clay particle precipitate readily.

 

Regaards,

Charles

[Dennis in Uvalde]

I'm new too and don't have a 100 mesh sieve– yet– we're a long way from anywhere, so I use pantyhose stretched over a coffee can. I cut the middle from the rim of the lid to secure the hose. I put the crushed clay inside and shake it around, dusting the work surface then I use a plastic dough scraper to collect it.

I crush the clay by putting it in a coffee can with 1-2" pieces of scrap steel pipe, then I shake it and roll it around for a while. I just keep adding dry clay as I take out the fine dust for screening. It is a little slow (but I'm in Uvalde, what else is there to do) the remaining clay dust if very fine. I have a set for each kind of clay I use. I recommend wearing a dust mask. Great tip using TSP- Thanks

[Username]

I suppose you could do it with the dry clay, but most of the time slip and glazes are sieved AFTER they are mixed, thus eliminating the need for dust protection.

Sieving after mixing also eliminates the need for multiple sieves; you just wash your sieve and you're set.