I have some lovely leaves made from the original Hadar Jacobson copper clay.
I've pre-fired and fired and they haven't sintered fully.
The instructions have a pre-fire at 593 (which I made a mistake on, leaving the lid on the container and the valve in the kiln top (paragon sc2) when they should have been off) and a main fire at 843 or 827 if you are worried about blistering. You're meant to leave the venting hole open, which I didn't. Anyway it would seem I cannot read instructions (they were from a photo from a book, in my defence, so are a bit hard to see).
Now, I seem to remember firing the old Art Clay Copper at a higher temperature - over 900.
Does anyone have any advice for me on how to get them to sinter fully, otherwise I'm going to fire again at 900 and hope they don't blister.
Oh and I only have until Friday morning!!!