Question:
There is a new colored borosilicate wich works better than anything I have
used so far .And the best is, the priceis right and the upcomming stuff is
very interesting.We are gonna make colored tubing soon and will send it
exclusivly to our rod customers!
Answer:
-How can I get some of this glass in the USA?
-What is borosilicate....as opposed to Bullseye, as opposed to window glass
(float glass)
-Borosilicate is low expansion glass. You know it as pyrex. Beadmakers,
lampworkers, laboratory glass makers, and pipemakers use it.
- Borosilicate is a low expansion glass which must be worked at higher
temperatures (those go together) usually with an oxy-propane torch. What is
gained is the ability to work the glass more casually, as low expansion glass
is not going to crack as easily under heating differences. What is lost is
that so far, the choice of colors is much smaller. One borosilicate is Pyrex.
Window glass and Bullseye are called lime glasses because limestone is used
in the formula to make it easier to melt (amazingly enough, borosilicate
glasses are borax and silicate (sand) based.)
Bullseye is carefully formulated so that all its different colors work
together, especially at sagging and fusing temps. This is trickier than it
seems, requiring corrections to the base formula to adjust for the color
chemicals. Glass colors purchased for blowing, such as Kugler, gain in range
of compatibility by being made with lead, but even then, some of the
concentrated colors do not work well with other colors.
Window glass is also a lime glass, but the choice of ingredients is made for
economy, clarity, and quick setting from molten to stiff. Economy means that
cheaper sand, with iron in it giving it a green tone especially visible from
the edge. Quick setting also means that melted window glass (and bottle
glass) is difficult to blow as it stiffens up rapidly as it cools.
