Brittle PMC

[parkscale]

Hi does anybody have any idea if there is anything I can add to PMC metal clay to help it cinter better. I am kiln firing various silver metal clays and no matter what temp or how long I fire for it is very brittle and doesnt cinter properly. I am letting the kiln cool completly before opening the kiln so as to not shock the metal. etc, But it's still brittle.
Thanks.

[Caro]

Are you using fine silver or sterling? Sterling requires firing in activated charcoal or the oxidation of the copper content prevents it sintering.

Fine silver clay is the easiest to sinter and very forgiving. I usually cook for at least 30 minutes at 820C but I've also done it for longer at lower temperatures when embedding glass or gemstones and I've never failed to have silver sinter.

If you are using fine silver have you checked the temperature of your kiln?


It's also possible to torch fire small pieces of fine silver.Does that work OK for you?