AusBonsai

[quote="Lynette cover the join with slip. I use the clay used for the pot an equal amount of ripped up toilet paper and water and vinegar and mix to make a smooth slip.[/quote]

Thanks Lynette. This will really help me with my first pot. Could you show us how to make the slip (in general)?
DK

Hey Kvan. Until Lynette finds time to get to your question.

Take a small amount of clay. Rip up a small amount of toilet paper, put that in. Take a small amount of vinegar put that in. Then add a bit of water. Mush it all together. If you are not in a hurry let it sit around between mashings otherwise just keep mushing.
Mix to a paste consistency, don't fret too much about quantities.
It is ready to use.

As you work throw all the little dried bits of clay in the slip pot so they are not wasted. Top up with water vinegar and toilet paper as you think needed.

When you are finished working with it add a little bleach to stop any mold that comes from the toilet paper. Not that I think the mold is an issue if it does get it. I leave mine uncovered so I always try to remember to add some extra water when I have finished work so it hasn't dried out next time I go to use it.
If it does dry out, add water mix wait mix wait until it gets a paste consistency again

Thanks Bretts, I was just wondering if colour slips (adding colour stains for decorating purpose) are prepared using similar method?

Yes except there would be no need for the paper or Vinigar these are just to help jion the clay pieces. Slip as decoration is put on before bisque firing.
The applications with clay are endless. There is a technique where a pot is bisque fired then slip is put on. Then a glaze. When it is fired the slip cracks off and leaves patterns on the clay. I saw it with Raku and the smoke gave most of the effect but I have been intrested to try this in a normal firing.

An even easier way to make slip is use bone dry scraps, place in a bucket and cover with water. Let sit undisturbed for a few days, pour off excess water. Should mix easily without mushing, add back water as needed for the consistency you desire. This way you get a smoother slip, little or no lumps of clay. Starting off with wet clay you almost always have a few lumps even after mushing.

Right Bretts, I read some where that with the Raku firing (using saw-dust to burn), the smoke enters the cracks on the slip layer and creates marble like effect when the slip layer is removed

Kitoi, I haven't got any bone dry scraps yet I guess I could just use new clay with your method. Could I?

Sorry this one sliped by me.
I make the joining slip by drying some small pieces of clay of the same clay as the one I want to join pieces of. Just pull of samll pieces from the slab of clay and flatten them out so they will dry fast, if you use small flattened pieces they will dry inabout an hour. Then crush the dried pieces, then add about the same amount of toilet paper as the crushed clay. Mix this with white vinegar, I just buy 2l of no name brand, to give a slurry about custand thickness. As you mix the paper breaks up and you shouldn't be able to see any of it in the mix. As Kitoi say if you leave it over night it will just slake down. I am not always that prepared. I keep a large amount of joining slip made from the clay I use most, and don't use any bleach, I think the vinegar must act in a similar way. THough I keep it in a container with the lid on, so it is always ready to use. Hope this helps.
Lynette

Just on decorating slip. This can be made in a number of ways, the most basic is to just use ball clay mixed with water. The technique of naked raku is a little more complicated than just using slip. The slip I use for naked raku is a mix of kaolin, ball clay, sodium silicate and water, which is then burnished and a naked raku glaze is then applied, best sprayed on. After the raku firing the glaze peels off and the smoke effects can be seen where the glaze has cracked.
Lynette

Very informative Lynette. That's what I need to know for now. I haven't got a wheel but will try to hand build some pots next week and definitely will try out the crack effect method in your demo.
Thank you
DK