Clay Art Web Guide 
   
                                Articles
 
 Home   |   List a Site  |  Newly Listed  |  Link to Us  | Blog |  Bookstore  |  Articles  |   Classified Ads |  Search  |  Contact Us
 Antiques & Collectibles
 Architectural Ceramics
 Art Associations
Art Centers
  Artist Residencies
 Books and Videos
 Call for Entries
 Ceramic Exhibitions
 Ceramic Fountains
 Ceramic Info Sites
 Ceramic Jewelry
 Ceramic Masters
 Ceramic Murals
 Ceramic Publications
 Ceramic Suppliers
 Ceramic Tiles
 Ceramic Restoration
 Ceramic Web Search
 Clay Artists
  Clay Beads
 Clay Instruments
 Craft Shows
 Crystalline Glazes
 Earthenware Pottery
 Figurative Sculpture
 Functional Ceramics
 Galleries
 Glaze Software
 Guilds & Associations
    Kosai Ware
 Lusterware Ceramics
 Majolica
 Miniature Pottery
 Mosaics
  Naked Raku
 Native American
 Paper Clay
 Pit Fired Pottery
 Polymer Clay
 Porcelain
 Potteries
 Potters
  Potters Guilds
 Pottery
 Precious Metal Clay
 Raku Pottery
 Saggar Fired Pottery
 Salt Fired Ceramics
 Sculptural Ceramics
 Sculptural Vessels
  Smoke Fired Pottery
 Stoneware Pottery
 Terracotta Pottery
  Travel and Tours
 Virtual Galleries
 Wood Fired Ceramics
 Workshops

Advanced Preparations of the Ware

One can “manipulate” the surface effects by various treatments. Here are a few of my favorites:
 1. Colored Effects

a.

Colored clays: Inlaid colored clays often give an interesting contrast of design to the random flame painted patterns from the pit fire.

b.

Colored slips or terra sigillata: Stains (less than 8%), cobalt carbonate (less than 0.5%), and copper carbonate (less than 10%) can be used creatively to offset pit colors.

c.

Stains or oxides can be put on the pots before or after bisque firing.

d.

A variation of Paul Soldner’s Raku Halo effect can sometimes be obtained by brushing on designs with a mixture of 50% copper carbonate with 50% red iron oxide in a water solution over a white slip or body. Temperatures must approximate 1650˚F with heavy reduction followed by re-oxidation.
 2. Wire Effects

e.

24 to 32 gauge copper or steel wire can be wrapped around a pot to create linear patterns that can result in black, red, green, or “shadow” lines depending on the metallic content of the wire and local firing atmosphere. Interesting impressions are also possible using copper or steel mesh kitchen scourers that are unfolded and placed or wrapped on portions of the pot.

f.

Hardware cloth or chicken wire fencing can leave interesting metallic patterns of black or grey to contrast with the pit flame painted fumes.
 3. Cloth Effects

g.

Cotton string or sisal twine soaked in 10% salt (ordinary or sea) water, dried, and tied onto the surface gives green, black, brown, or maroon colored line patterns.

h.

Pots can be wrapped in old tee-shirts similarly salt soaked and wrung. Burning in the pit enhances the orange color from salt and/or the reds of copper carbonate. If reds are desired, it is important not to disturb the ash that forms from the tee-shirt combustion because it creates the required local reducing atmosphere.
 4. Saggar Effects

i.

Clay saggars: Pack pot and combustibles in a bisqued clay container to trap the combustion gasses in the same fashion as you do in a gas kiln saggar firing. Muted “soft” colors emerge.

j.

Therma-foil (temperatures up to 2000˚F, available from LL Kilns - hotkilns.com): This material can be used for varied saggar effects that impart metallic flashes. The saggar can be lightly stuffed with color enhancing combustibles and chemicals.

k.

Heavy duty aluminum foil: Pots may be sprayed with ferric and sodium chloride solutions imparting red to orange hues. Note: aluminum foil starts to melt at 1100˚F. Do not place these saggars over or touching another piece.

l.

Slip coated paper saggars: The ware, combustibles, and chemicals can be placed into a paper bag then encased in paper soaked in clay slip.
 5. Masking Effects

m.

Shards or pieces of metal can be placed on the pot’s surface to mask it from flame and fumes.
 6. Marking Pen and Paint Effects

n.

Experiment with black and colored ink markers to see which survive the fire.

o.

Use copper markers and copper containing paints (aerosols are convenient) for “controlled” coloration.
 7. Cages and Containers

p.

Sometimes you may want to create a more contrived local combustible environment for your piece and not depend so much on the haphazard pit construction for effects. If you are confidant that your work does not need much pre-heating, then place your work, chemicals and combustibles in a cage made of wire, cardboard or supermarket paper bags.

q.

Very delicate, thin, or greenware pieces may be placed in a cage made of wire or steel to protect it from being crushed by heavy wood or by other pieces. Fumes easily pass through the cage.
 8. Crackle Surface

r.

The clay surface will crack in random patterns if you press too hard during burnishing or apply more than eight layers of Terra sigillata. The crackles will often take on different contrasting colors during fuming.
 9. Low Fire Glazes

s.

These may be used in a pit but care must be taken that glazed surfaces of pots do not touch other ware as they will adhere to one another. (Sometimes only the insides of pots are glazed.) Ash and other combustibles will also attach to the glaze but these often can be scraped off with sometimes interesting results. Temperatures in the pit reach earthenware temperatures.
These “advanced” techniques can be used in any combination you choose. Be aware of potential impact on surrounding pots, be they yours or someone else’s.
 

1 2 3 4

Reproductions of this article are prohibited without expressed written permission from Eduardo Lazo.  © Copyright 2003 Eduardo Lazo. All rights reserved worldwide.

             
Copyright © 2000 - 2010 Clay Art Web Guide™  All Rights Reserved.