This will give you the

[Stephen Richard]

This will give you the information you need.

http://www.bullseyeglass.com/methods-ideas/annealing-thick-slabs.html

You don’t need to worry much about the heat up as the glass is all in pieces.  Choose the schedule for one up from the diameter of your tube.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/ and  http://www.glasstips.blogspot.com/