I wrote this to a student who wanted to understand the types of glass that are most popular for Flame-working. (melting the glass with a torch)
The difference between glasses are the fluxes, or compounds that are added to the silica. Some make the glass melt at a lower temperate (soda & lime), some make them heat resistant (boronite), more reflective (lead), shatter proof etc…
The different types melt at different temperature and more importantly have different ways they need to be cooled down to room temperature from the molten state.
Borosilicate is melted at a relatively high temperature and soda lime at a lower. Boro is almost like driving standard, it takes longer to heat and is stiffer. It is also used for laboratory apparatus and you can buy it in tubes and rod.
Soda lime is the type of glass used in most furnaces, or hot studios where people use blowpipes and punties. Tubing can also be pulled in a hot shop, but it’s harder to find it as a product on line. Until hobbyist started making glass beads, you had to pull your own colour cane at a hot studio, but now there are many companies in the states that make pre-cut, ready to go rods.
ok, so I also explain to the kids that soda glass is the breaky kind, you have to introduce it into the flame slowly, whereas boro you can pretty much stick right in the flame. Most people have quicker success with the soda and creating beads when they are starting out. I hope helpful.
There are some great videos on y-tube. Just watching will help you understand the way the different glass moves.

Peace & love, natali

www.natali.ca