Art Chowder September | October, Issue 23 | Page 23

Art Chowder:   What makes
borosilicate glass different from
traditional glass?
Chorvat: What differentiates
“borosilicate” from regular glass
is the boron in it. It’s really just a
cleaner form of soda-lime glass that
doesn’t contain as many impurities
as “softer glass” — while being
“doped” with boron to form a more
homogenous molecular structure.
That extra element unifies the
molecular matrix inside the glass
into one piece instead of several
broken up chains, which is what
exists in soda-lime glass. 
Art Chowder:   Why work with
borosilicate, though? Why not
traditional glass? 
Chorvat: The reason I started working
with borosilicate as opposed to
traditional soda-lime glass, was
based on my love of the curious
nature of materials. Not very much
had been done, artistically, with
borosilicate glass. It was a brand
new thing, and I found a great deal
of intrigue in experimenting with it.
The strength, durability, and archival
nature of the glass is what really
attracted me to it. When you make
a piece it’s nice to keep in mind that
what you’re making will actually
become part of the rock cycle. It
gives you a sort of power that what
you are making will become part of
the earth. It stays around that long.
Art Chowder:   So how did you learn
to work with borosilicate?
Chorvat:  My grandmother, Doris
Chorvat, was a professor at Western
Washington University.
Her involvement and help with the formation of the Pilchuck Glass School, in Stanwood,
Washington, allowed me to be around and experience a more academic view of
glasswork. Plus she had many collected pieces that inspired in me a desire to recreate
brilliant and unexplainable displays of light through glass. 
When I attended Pilchuck Glass School there wasn’t much information available about
color in this medium, or understanding of the capabilities and properties of borosilicate
glass. Mostly through trial and error, I transposed the technique of traditional (soft)
glass into contemporary compositions of borosilicate (hard) glass — with a great deal of
success. 
We (my class) would experiment with materials to see what happened and when we had
strange results we’d just continue in that direction. In one of our experiments, I noticed
nuances in colors produced by a silver coin. After I heated it up in specific atmospheres,
with specific temperatures, brilliant layers of pure color would emerge. I found that
something unique and malleable was happening in the surface almost instantly so I just
sort of played around with it to see the effects of putting it into different atmospheres at
different temperatures. Eventually, I was able to create predictable rainbow colors with
the silver.
September | October 2019
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