About

This candle holder was made by letting glass drape over and around a stainless steel mold during its kiln forming stage.

 

Sandra A Wills is a multi-dimension artist known for her kiln-formed warm glass creations and jewelry designs.  Before focusing on jewelry and glass, Sandra studied graphic design, and worked as a technical writer, editor, and documentation manager.  Needing a break from the tech work, Sandra started designing and selling jewelry in 2005, then added a kiln plus glass creations to her offerings in 2008.

Presently, Sandra finds herself quite busy with glass work, her family, and freelance technical writing. She is also a board member of the Holly Springs Arts Council and will be returning to the Waverly Place Farmers Market for her 2nd year. A local to North Carolina and a true Tar Heel, Sandra and her family have called Holly Springs home since 2002.

 

 

Behind the Glass

This bowl was made by slumping the glass into a ceramic mold during the kiln-forming stage, allowing the glass to settle into the curves of the mold for a nice organic shape.

This bowl was made by slumping the glass into a ceramic mold during the kiln forming stage, allowing the glass to settle into the curves of the mold for a nice organic shape.

The fused glass items I create are made using a process called “glass fusing” or “kiln forming.” This process may also be referred to as working with “warm” glass, because the working temperatures of kiln formed glass lies halfway between the extremes of glass blowing (“hot” glass) and stained glass (“cold” glass). I personally like the term “warm glass” as an artistic expression of what I do, but “kiln formed” is probably a better description.

The techniques I use include:

  • Glass Fusing –  joining pieces of glass together by melting them in a kiln. This is done at temperatures around 1400-1530F, depending on how much or little glass texture is desired. The flatter the piece, the hotter the kiln run. Lower temp fuse firings are often called tack fusing or contour fusing, where the glass pieces are hot enough to join but not hot enough to completely flatten out.
  • Slumping – using a ceramic mold coated in kiln wash (which keeps the glass from sticking to the mold) to shape glass in a kiln and make three dimensional items like bowls and plates.
  • Draping  – using a stainless steel mold covered with fiber paper (to prevent sticking) or a special high temp mold release spray to shape the glass in a kiln, making three dimensional items like vases and candle holders, as well as other vessels.
  • Pot Melts – using a ceramic mold with holes drilled into the bottom (uncoated) which has been raised several inches above the kiln shelf to melt glass pieces (usually around 3lbs worth) and allow them to flow together to create a truly unique piece of glass. This process is done at a temperature around 1600F.

The glass for kiln forming is purchased already colored. The coloring is created at the glass factory by adding various chemicals and elements to the silica mixture that is heated to create the glass. There are four main types of glass used in glass fusing:

delphiglasspack2

Glass packs like this one from Delphi Glass offer a variety of glass in 12″x12″ sheets.

  • Opalescent glass – opaque glass that you can not see through.
  • Cathedral glass – transparent glass.
  • Iridized glass – either opalescent or cathedral glass that has been coated with a metallic coating made of tin. This coating can be silver colored, gold colored, or have a rainbow transition from gold and silver, to purple, blue and green. There are also patterned and textured iridized glasses. Different effects can be obtained depending on whether the iridized coating is facing the bottom of the piece, the top surface of the piece, or is sandwiched between layers of glass.
  • Dichroic glass – Thin layers of metallic oxides, such as titanium, silicon, and magnesium are deposited upon the surface of the glass in a high temperature, vacuum furnace. This creates a brilliant coating on the glass that displays more than one color, especially when viewed from different angles. This is most often used for jewelry.

The glass is purchased in sheets of varying thickness, crushed glass (frit), powdered glass, thin rods (stringers) and thin shards of glass (confetti).

Any glasses fused together have to be tested “compatible” or they will crack upon cooling. The glass I prefer to use is 96 COE, and I love how easy it is to work with and cut.

 

Glass has to be heated slowly, and can be brought to specific temperatures to achieve different effects. It then has to be cooled slowly to complete the  annealing process. The kilns for glass fusing are usually computer controlled to achieve consistent results. However, in spite of this each hand made glass item will be different, and certain inconsistencies or imperfections are part of the mystery and beauty of this process.

Example of glass after flowing through a pot melt bowl with five holes drilled at 1600F.

Example of a unique piece of glass after flowing through a pot melt bowl with five holes drilled in it at 1600F for an hour.

slumpypotmelt

An example of a pot melt kit from Slumpy’s — note the ceramic bowls with holes and the raised stand which allow the glass to melt and flow to the kiln shelf below. The stainless steel ring allows the glass to be formed into a disc, containing the shape of the flowing glass.

Stainless steel molds from Slumpy's used for candle and vase drapes.

Stainless steel molds from Slumpy’s used for candle and vase drapes.

delpibowlmold

Example of a ceramic bowl mold as offered by Delphi Glass