I just cast silver in three 5 inch flasks. It is extremely difficult
to use tongs to handle hot flasks this size…
To solve the handling problem I remove a small portion of investment
next to the edge on both ends of the flask before putting them in
After burn out use tongs to work the flask to the front of the oven.
I then use a large pair of vise grip pliers to clamp on the exposed
flask edge to lift it from the burn out oven.
I then switch the pliers to the sprue end of the flask and place it
on the vacuum table. Disconnect the pliers and pour the metal.
Clamp the pliers on the flask to move it to the cooling place.
Remove the pliers and reconnect prior to quenching.
The vise grips work very well for handling large heavy flasks.