This post from the SBD's pyrex tube thread...
That's the one that has everyone running to fused quartz.
I've been melting glass (torchwork) for over 10 years now and I would only recommend using fused quartz. You guys are going to have boro blow up in your faces. I can guarantee it. Really! I've had it happen enough and it doesnt take a glass torch to shock boro glass! I dont have to look up anything on the internet to know first hand from my experiences working and melting both quartz and boro glass that its an accident waiting to happen. ONLY USE QUARTZ GLASS!!! Besides quartz is a better conductor and its going to take a hell of a lot more heat than boro before any shocking.....
Bedazzle
That's the one that has everyone running to fused quartz.