I did ceramics for a semester, was fun. Not sure if you need any more help though by the looks of it.

If it is completle dry take some newspapers and put some water on them then place them over dry parts. Do not put water on dry parts.
If u have some cracks take some vinigar and mix it with parts of totally dry clay. You can only do that when cracks and sculpture are totally dry.
Do not mix clays use one kind of it, and also do not mix clay with plaster.
There is a great book called The Complepte Potter from Steve Mattison. You have there everything about ceremics.

This post was edited by Rerna63 on Jan 16 2013 01:55am

thanks guys and tanner, it'll be more than one inch thick, my teachers was about a 2.5 inch diameter and 5-6 inches tall
so it'd be best to hollow that out to avoid it exploding in the kiln?

If it's so small there's no point

he told me clay should be no more than one inch thick though

Take that advice with a pinch of salt, its not set in stone.
Just use common sense, hollow it out if you can. Exploding in the kiln is from the expansion of the moisture as it turns to steam. Allow the piece to dry fully and have no pockets of moisture. Any large solid areas of clay need to be hollowed out. Trapped dry air will never cause an explosion.

Avoid moisture pockets by kneading the clay well. In the kiln turn up the heat as slow as you can (but I'm guessing if you're in high school or whatever you won't have this privilege). Heating thick clay slowly at the beginning allows you to dry off any water before it turns to steam; even bone dry work as a small percentage of water in them, like drying lumbar in a kiln. The thicker the piece, the longer it takes for the clay to warm up and for the water to evaporate.

This post was edited by CHurley on Jan 16 2013 07:22am

how about you make me a cup out of clay so i can fill it with all the care i don't have

#bitter

This post was edited by nerobellum on Jan 16 2013 08:13am

m8 do you just follow me around and try to one up me?

fine, OP.

take this dude's advice, i give up.

same

2.5 inches it will for sure explode....

1 inch is pushing it and has a 50/50 chance to survive....