i CANNOT fire a delicate, air-bubble-filled, clay piece!?

Question

i want to make a duplicate... (so i can fire, stain it)
can i do a rubber casting with a bisque piece? while still saving the original?

edit!
GREENware, raw, never fired clay peice.... not bisque. whoops.

Answer 1

Consider using latex molding material with a plaster backing to copy the original.* This material is relatively inexpensive ($10-12 for enough for a bunch of molds) and is painted on in thin layers to build up thickness (don't try thick layers, they take forever to set) You will have to do at least one dividing line, but not as many as with a solid mold. If the item does not have a flat surface, use plastic clay (plasticine) to make a pouring point. If it is flat, leave latex off of that part and use it to pour. After the latex mold has finally dried to amber and is about 1/8" thick, use the dividing lines to make a plaster backing, which can be pretty crude since it only has to support the rubber not match every detail. Take the plaster off as soon as it is firm, marking the fit. The latex will have a white tone from the moisture. Let it dry back to amber for maximum strength then peel it off the form. When the plaster is thoroughly dry, assemble the rubber and plaster form and pour a plaster copy. When it is really firm, remove the plaster support and peel off the rubber carefully, especially if the item has a lot of ins and outs.
Now you have a new original from which you can make a multipart plaster negative that you can pull off in sections and you can slip cast in the negative.
* If the original has a very pitted or bubbly surface, you may wish to consider filling the pores with soft soap or solid shortening. Of course, what you choose needs to be able to be washed out, leaving the original undamaged.

Answer 2

You could make a rubber casting, but the supplies are expensive and you can't cast clay into rubber, it needs air to dry - so you would need to cast it in plaster and then make a plaster mold for slip casting - depending on how complicated the piece is you may want to go ahead and just make a plaster slipcasting mold.
Making slip cast molds is time consuming and complicated - I would suggest you try to find a ceramic artist in your area who can demonstrate the process.

Answer 3

welcome to the club, kid...neither can i.