Working with borosilicate

[Samantha BeanHead]

Hi,

I recently read info on a few websites about glass blowing for
producing scientific apparatus such as tubes and flasks ect. One site
showed that an amateur can work easily enough with soda lime glass
using a regular blow torch from a DIY store that burns propane/butane.
I'm wondering if I work with borosilicate glass which has slightly
higher melting and workable temperatures whether such a torch will be
hot/effect enough... ?

Thanks :)

[Andreas Haimberger]

"Samantha BeanHead" wrote:

[...]

One site showed that an amateur can work easily enough with soda
lime glass using a regular blow torch from a DIY store that burns
propane/butane.
I'm wondering if I work with borosilicate glass which has slightly
higher melting and workable temperatures whether such a torch will
be hot/effect enough... ?

It is possible to do very simple work, like bending of thin rods, for
example, but you can't do serious work with such torches. You have to
use special burners with a mix of oxygen and natural gas or oxygen and
propane/butane.

The working temperature of boro may seem to be "slightly" higher, but
it is impossible to do such things like sealing tubes together, etc.
The flame temperature of simple torches (e.g torches used for
soldering, or "weed burners") is much too low for working with
borosilicate.

The other thing with such torches is, that it is impossible to control
the size of the flame in a reasonable way. If you want to work with
tubes or flasks and do sealings or joints, one is usually working with
very different sizes/temperatures of the flame. A torch (like these
"weed burners", for example) usually has two sizes: "big" and "very
big". No chance to control flame temperature or flame size in a
reasonable way. "Reasonable" in this context means "useful for a
boro-glassblower".

Andy (worked many years as a scientific glassblower)