[Okapi]

i am doing a sculpture larger then my kiln size. I need to cut it into sections in order to fire it. I do hand built sculptures. What I need to know is when I cut it apart to hollow it out do I need to place the sections back together so that they dry at the same rates. If i fire it in sections will it warp not being together in the kiln? Have to do in sections because lost the first one after 50 hours because to large to carry to the kiln because of composition of subject and can not place against body to carry. Any help? Have to finish sculpting it by Friday?

[Chris Campbell]

I don't do large sculptures, but can add information to some parts of your question.

Some potters hollow out large sculpture pieces when the clay is just hard enough to handle
where it won't distort but still is soft enough to scrape out.
You can reattach the pieces quite easily at that point.

Parts fired separately will probably distort so they will not fit well afterwards.
So cut it in a place where it will not show as much.
Or, design it. It a way that it won't show ... Or look like you meant it.

People who build large work often build a temporary kiln around the piece for a one time firing.

[Ginametrical]

Chris Campbell, on 07 July 2010 - 11:10 AM, said:

Parts fired separately will probably distort so they will not fit well afterwards.
So cut it in a place where it will not show as much.
Or, design it. It a way that it won't show ... Or look like you meant it.

I agree with Chris. I do extruded sculpture, so I am faced with joining sections together all the time. It is the biggest obstacle in my work.

For me, I make sure the edges of the sections to be joined are sturdy, strong and uniform. I make the rims on these sections a little thicker than the walls of the rest of the sculpture. Also, my extrusions are square, so I use an inner circle die inside of the outer square. That gives more weight distribution and structure to the corners of my pieces. Not sure if your piece is organic or geometric, but it might help.

I do have problems with distortion. I can't avoid it. But like Chris said, either become excellent at repairs or use the breaks in your pieces as part of the design. I usually try to put breaks at unassuming places, then go in with spackle and fill. I then usually try to mimic the glaze using a variety of diffrent materials over the spackled juncture.

Good luck to you! Practice - it is definitely something that I myself am still struggling with.


Gina

[hansen]

What I can tell you may not help you right now. I have seen larger than life size sculpture figures created and fired in one piece in a car kiln. The kiln car was actually used as the support in all stages of making the work 8' x 4' x 6' - a bed of soft brick and a layer of grog beneath. The car kiln was built by a former student who researched the design of the kiln. A fork-lift truck was needed to take the piece out of the kiln's car after firing, and loaded onto a vehicle at the loading dock. Although you can actually build a kiln around a large piece to be fired in situ, i have seen articles on this too. Lots of soft brick (hot face).

Working with sections - as with all clay - the best joining is as moist as logistically can be accomplished. Nothing is gained when joining clay by waiting unless for some other logistical reason (like transport). If pieces are fired separately they may not join well after-wards but this can be controlled by what type of non-plastic materials are in the clay, and to what temperature they have been taken (I mean cone)

h a n s e n

Okapi, on 07 July 2010 - 08:46 AM, said:

i am doing a sculpture larger then my kiln size. I need to cut it into sections in order to fire it. I do hand built sculptures. What I need to know is when I cut it apart to hollow it out do I need to place the sections back together so that they dry at the same rates. If i fire it in sections will it warp not being together in the kiln? Have to do in sections because lost the first one after 50 hours because to large to carry to the kiln because of composition of subject and can not place against body to carry. Any help? Have to finish sculpting it by Friday?