As far as a seperator for processing (heat cured) dentures, injection or whatever Ivoclar makes an excellent "tin foil" subsittute. Best I've ever used in 40 years. As this discussion de-evolved into a repair discussion try this. Another Ivoclar product that I swear by is their lab putty. Make a...
Press Pack Denture Flasks
I have used brass flask forever. I've alway used Hanau flasks. The last ones I purchased were not as well manufactured as they were in the 70's. Anyway they are the easiest to use, clean and maintain.