Kat,
Some will tell you you need a bigger hammer, and that may work, but I have found to get catchers / pots that separate easily:
1) Make sure the diameter of your catcher is the same as that of the foot of pot and that the surfaces are in the same plane. An overhanging catcher or acute angle at the intersection will give glaze a place to accumulate and cause removal problems.
2) Lap the top of the catcher and bottom of the piece so that they mate perfectly. Rinse or sponge them to clean and remove all loose material.
3) Make a mixture of white glue and kaolin by combining roughly equal amounts (by volume) of the 2 ingredients. When you begin mixing them (with a spatula) you will have something akin to lumpy pizza dough. After a little while it will take on a more smooth consistency as the glue wets the kaolin. You can add a little water to thin it out some, but don't put in too much. I'd keep it somewhere between the consistencies of toothpaste and honey.
Note: Use kaolin and not alumina. Alumina is wet by the glaze and will allow the glaze to wick into the seam. Kaolin is not wet by the glaze and will prevent the glaze from wicking into the seam.
4) Apply a bead of the mixture to the top of the catcher with a brush or spatula. I have put the mixture back in the glue bottle, but found it tedious and that I had to enlarge the opening of the glue bottle.
Nestle the pot onto the bead on top of the catcher and allow the excess to extrude out of the joint. Hold it until the glue dewaters and sets firm or you may find the pot slides from side to side.
5) After the extruded mixture firms up (~5 minutes) remove the excess with a trimming tool. Sponge the joint clean. Make sure to remove all glue / kaolin that may have made its way onto the pot. Slop on the catcher really doesn't matter as you will throw it away.
6) If you are glazing immediately make sure to handle the assembly by the catcher. If it sits overnight and hardens you can handle the assembly by the pot.
7) After firing remove the catcher. If your cooling cycle is fast, and you have well mated catcher / pot surfaces, you will find some of the catchers literally fall off by themselves. If no,t some will come off with a light tap from a hard object. If they are still stuck use a torch and heat the catcher just below the joint until you hear a "tink" at this point the catcher has expanded and broken fr*ee from the pot.
8) Lap the bottom of the pot and the edge while rotating the piece . If you did a good job of lapping the top of the bisqued catcher and bottom of the piece so that they mate perfectly this will take minimal effort and the bottom of your pot will be nice and smooth and clean.
I hope this helps you. I went through the same thing just over a year ago and know what you are going through.
Phil



Kat Morrell wrote ;

> Morning all,
>
> While many of the crystal illuminati were doing mind melds in Virginia, I was in my studio - grinding....and grinding....and more grinding. I had made pedestals from the same Cone 6 porcelain that I use for my pots, then brushed the top with liquid kiln wash and then set the pots on top of the pedestals in my kiln.
>
> The pedestals didn't break off from scoring, hammer and chisel, or tourching the riser. I finally got them off by brute force, then had to grind about an inch of riser from the bottom. It has taken me days of grinding to get down to the pot.
>
> I'm taking Holly's advice for this next kiln load and making damn sure that the pedestals and attached in such a way as to break off with as little grinding as is necessary.
>
> I have read in several books to mix alumina, kaolin and wood glue together (or just kaolin and wood glue) and using that on the riser to form a tight bond. Is this mixture the consistency of toothpaste? or more liquid? any other ideas on how to attach the pedestal to the pot to promote a clean break?
>
> Bill Schran has makes biscuits from alumina, kaolin, sawdust. Bill - how exactly are these biscuits manufactured? Do they have glue in them? are the bisqued first? Do you mix up a bath and spread it out on a flat pan,let it dry, then cut it into circles?
>
> I bought some soft bricks to try the method of slicing them, then cutting them into discs and glueing them on.
>
> I have a load of bisque pots waiting for my next glazing run....but I really want to figure out the glueing on of the pedestal before I put them in the kiln. I would love any advice on this important step.
>
> Thanks again for all of the great ideas you have shared with me.
>
> Kat in Seattle