Tuesday, March 4, 2014

Ceramic Bead Quality through Chemistry

To continue on with the discussion about Ceramic Clay Beads, the one absolute thing that must happen for earth clay to become ceramic clay, is a firing of the materials to a high temperature where the materials - on a molecular level bond together. Click HERE for a great explanation of the firing process.
For the most part, ceramic artists bisque fire their wares to around 1750 degrees F so they can paint ceramic glazes on them.
Marsha Neal Studio Bisque Fired Ceramic Beads
Ceramic artists also may want to layer underglazes by brushing on and wiping off the colors in layers. This could not be achieved on greenware (unfired clay) without layers of clay being removed as well.
Jenny Davies-Reazor ceramic glaze fired pieces:
Technique: Color on, wiped off, layered more colors on, wiped off, clear coated, glaze fired.

The second firing - the glaze firing - is usually much higher, bringing the ceramic clay close to vitrification.

Sometimes ceramic artists are able to glaze their greenware pieces and do a "once firing", but it is not a frequently used technique due to high breakage of greenware while glazing.

A ceramic glaze that fits the clay body and is fired to these almost vitrification temperatures (upwards of 2200 degrees F) makes the ceramic clay quite durable. Here is a link to explain a bit about glaze and clay "fit" issues.

Glaze firing beads can be a bit tricky because the glaze will flow down the piece when it is fired in the kiln and if the glaze touches anything it will fuse to it.
Marsha Neal Studio Fused Glazed Bead Pendants that touched in the glaze firing.
Some people decide that firing their work with a non-glazed back is the way to go - this is either a decision made by artistic choice or because you are firing to a much higher temperature than the Nichrome rods can handle or maybe the community kiln you are firing work in doesn't want to spend the time to load each tiny bead by bead as it is a quite tedious thing to do.
Jenny Davies-Reazor Cone 10 Reduction Firing Pendants
Some ceramic bead makers like to suspend their work from a bead rod or nichrome wire that has been cleared of glaze (see my previous post). Nichrome rods can go up to Cone 6 firing, but will often sag under weight at those temperatures.
Marsha Neal Studio Kiln Firing - Suspended Beads and Pendants
GLAZE SAFETY: Always try to minimize the amount of ceramic clay or glaze dust you create by wet sanding or sponging your underglaze or glaze out of bead holes. Wear dust mask, goggles and gloves to protect yourself, and wet clean your area immediately after to avoid making excess dust.

NON-FIRED or COLD GLAZING on CERAMIC
What if you are working with ceramic beads and you want to use a non-fired painting (or cold glaze) technique to finish your ceramic work? Looking past the many cringing faces of traditional ceramicists - trust me - just about any serious ceramic potter or ceramic artist cringes just a bit when you talk about "painting" your ceramics and not "firing" them - that is just the way it is with the magic of fire and kilns and the interaction of the glaze material on the ceramic clay body during the firing...

If you are at point where you want to paint your ceramic clay in a non-fired finish, you want avoid it looking like a child did it without any thought or care, because that is just pretty offensive to the ceramics art community (sorry, I have to be blunt about that). You want it to be of the highest quality as possible, expressing your own personal artistic vision. Push yourself until you achieve what you are wanting to express and then stand behind your work and feel proud of your work.
In progress image of painting ceramic beads with water color paints.
Artists looking to paint their ceramic clay can use air dry, cold glaze, or heat set (think heat guns or oven temperatures) products. These include paints - oil, acrylic, water paints, pigments, dyes, colored pencils, pastels, wax, guilders paste, etc. Some of these materials work fine layered directly on bisque ceramic beads, and sometimes they need a thin layer of gauche - as they are little ceramic canvases if you think about it. Cold glaze refers to something that was air dried then sealed for protection.

Often, the time it takes to layer on, remove layers, paint more layers - letting layers dry in-between, makes a bead cost the same if not more expensive than a similarly glaze fired ceramic bead. Pricing of work like this is all about the artists time that goes into finishing that item, and to the quality of the work in question.
So no matter if you glaze fire your ceramic piece (kiln fired glaze finish) or you bisque then finish it with "non-fired" or "cold glaze" techniques, it is always important to make your best work, understand your material, make sure the surface of your ceramic work is sealed for longevity (if required) and communicate clearly what material you are using and the suggested intended use. Think about safety when intended use comes to mind, as ceramic clay edges can be sharp if they are broken, and often are not really great around young children as they tend to drop, bang, hit, throw, and eat anything they get their hands onto.

Here are a few other recent blog posts about ceramic beads if you are interested in educating yourself more about this versatile material:
Mary Harding for Art Bead Scene: Inside the Studio
Caroline Dewison for Art Jewelry Elements: The Life of a Bead
Natalie Pappas: What Makes "Ceramic Clay" Ceramic?
Lisa Peters Art: Celebrating Ceramic
Jenny Davies-Reazor: Ready. Glaze. Fire! (Cone 10 reduction firing and ceramic pendants)

And remember, we'll be updating our Love My Art Jewelry Ceramic Clay Pinterest Board with links to artist pieces, ceramic clay educational posts, tutorials, and such.

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