Answered By: Regan Brumagen Last Updated: Nov 22, 2016 Views: 82
From Dr. Robert Brill, Research Scientist Emeritus:
The "slumping temperature" and annealing range will depend very sensitively on the composition of the glass you are using. They can vary widely from one glass composition to another and could even vary somewhat from one kind of window glass to another.
The time required to anneal a piece of glass depends not only on the composition, but also on the size and shape of the piece. Larger and thicker pieces require longer times than thin-walled pieces.
If you have not done work of this sort before, I strongly advise you to contact some glass artist who has experience in forming glass by sagging. If you are working on pieces large enough to be called sculpture, you could risk having a serious accident.
You could try asking our Studio (on the Museum's website) to see if they can either give you some references or put you in touch with some appropriate glass artists in your area.