Beautiful, soft, muted-color brushstrokes and washes of water-soluble metal salts decorate Gary Holt’s translucent porcelain bowls and plates. The simplicity and quiet presence of his works belie the years that Holt spent experimenting and perfecting his technique. Using water-soluble metals salts (WSMS) demands excellent technical skills and careful attention to details.
Barium carbonate has long been used as an ingredient in high-fire glazes, sometimes conferring unique properties upon glazes. One of the alkaline earth carbonates, it has also been used as rat poison (large doses can be toxic to humans as well). Glazes containing it ought to be checked for barium leaching if they are intended to hold food or drink, or reserved for surfaces that do not come into contact with food. It is not my intent to present the research on barium toxicity here, but to present a course of action for replacing it in glazes.
One of the more fascinating, sometimes frustrating parts of ceramics is learning to balance the innumerable factors that affect the outcome of a firing. Glaze ingredients, the clay body used, firing cycles, atmospheres, kiln-stacking techniques and geography (to name a few variables) can all affect firing results.
How many times have you copied a glaze formula, only to find that it didn’t work as expected? It is not unheard of for glazes with the same formula to produce different results. While this may seem like a dead end, it does not have to be.
For the past few years we have utilized several forms of rapid prototyping to explore new methods of creating form. At The Ohio State University ceramics program, we have a large Techno Isel CNC (computer numerically controlled) router and a Konica Minolta Vivid 910 3D scanner, a Z-Corp 510 3D printer and a soon-to-be-operational Epilog laser cutter. In an environment where research and development are crucial activities, we willingly embrace these new technologies in search of a balance between traditional craft and industrial practice.
The Many Layers of Kiln Wash: How to Find the Best Kiln Wash for Your Firing Temperature and Methods
In this post, John Britt explains that giving a bit more consideration to kiln wash might help potters avoid some of the common kiln wash headaches – like scraping cracked kiln wash off shelves or lamenting an otherwise perfect piece that was ruined by a flake of kiln wash. Plus he shares some kiln wash recipes for various firing techniques.
To achieve complete combustion, the exact proportions of fuel and oxygen are required with nothing remaining. In a gas kiln firing this is often difficult to attain because of the many variables in fuel and oxygen (which is derived from the air) and the equipment used to mix the two.
As John Britt points out in today’s post, firing to cone 6 reduction is cheaper, faster, and the results can be almost indistinguishable from high fire.
The old adage that time equals money is especially true in any labor-intensive activity. Making pottery is certainly an endeavor that requires direct labor to produce pottery for sale. Handmade pottery by definition requires physical attention from the potter during many stages of the operation.
As a field, we are particularly good at time travel, but really only in one direction. We can, and should, start to look forward-further and more often than we do. Many potters define their work by how it differs from industrially made work. For example, the industrial pot is seen as flawless, boring, identical, sterile, cheap, safe and lacking a personal connection to the user. This critical definition goes back to William Morris’ 19th-century attack on industrialization and his subsequent championing of craft.