Pkqw #24

[bciskepottery]

Week 24

Note from Pres: The questions this week are taken from an older book. The book is about electric kiln ceramics, and unless otherwise stated, assume an electric kiln when talking about firings.

 

1. The main alternative to creating and reducing atmosphere in the kiln is to add reducing materials to the glaze. Several materials are available but by far the most useful and one with the author has experimented is _____________________.

   1. bone ash

   2. soda ash

   3. silicon cabide

   4. sodium silicate

2. To fit well, both before, during and after firing, body and glaze must expand and contract at much the _______________________ and to much the same extent.

   1. same rate

   2. differing rate

   3. same hardness

   4. none of the above

3. One method of joining together a burnt-out element. Stretch the wire and interlock; dab the join with ___________. Turn on the electricity supply , which will cause the wire to arc at the joins and fuse together.

   1. Kiln cement

   2. oil

   3. water

   4. super glue

4. A _______________ glaze develops because the glaze contracts when cooling more than the body, this can happen with shiny or matt, colored or clear glazes.

   1. Glossy

   2. Lava

   3. Matt

   4. Crackle

This weeks questions come from Electric Kiln Pottery-The Complete Guide, by Emmanuel Cooper, c. 1982, Anchor Press for B.T. Batsford Ltd.

 

Note from Pres: A much older book that helped me years ago to explore cone 6. This was the first book I was aware of at the time that had a full chapter on Cone 6 Ceramics, and glaze recipes of which Floating Blue was on I first used.

 

 

Answers:

1. 3. Silicone Carbide-The main alternative to creating a reducing atmosphere in the kiln is to add reducing materials to the glaze. Several materials are available but by far the most useful and one with which I have experimented is silicon carbide (SiC) better known as carborundum.
2. 1. same rate-Here the problem is to achieve a good fit between body and slip. Shrinkage has to be much the same and a good bond has to form between body and slip.
3. 3. water-One method of joining together a burnt-out element. Stretch the wire and interlock; dab the join with water Turn on the electricity supply, which will cause the wire to arc at the joins and to fuse together
4. 4. Crackle-The development of craze lines in the glaze which are recognized as a decorative feature are known as crackle glazes. . . .. On pots intended for functional use such a crackle creates both a poor bond between body and glaze, which makes it physically weak, and a trap which can hold food and make it unhygienic. For these reasons crackle glazes are best reserved for use on decorative pieces. A crackle develops because the glaze contracts when cooling more than the body, and this can happen with shiny or matt, colored or clear glazes.

[Chilly]

1

1

? Anything sounds dangerouse

4

[Judith B]

1 - I have no idea

2 - 1

3 - 3 (wanting to create an electric arc sounds really scary to me, I'd probably run away worrying it would explode in my face)

4 - 4

[Min]

3 - silicon carbide

1 - same rate

3 - water

4 - crackle

[S. Dean]

1.  3

2.  1

3.  3

4.  4

[Denice]

3,1,3,4   I was going to pick oil on number three but water makes  would arc better I think.   Denice

[LeeU]

3-1-4(?--I just like the stuff)-4