Earlier today I made a twistie of Effetre Dk turquoise, Effetre Sky Blue, CIM Mermaid (or perhaps CIM Rainforest) and Effetre Periwinkle.
I put it over a base of CIM Chalcedony and encased with Reichenbach clear.
Popped beads into the kiln... went back 5 minutes later and noticed that each one had cracked right down the mandrel line despite having been in the kiln only for about 5 mins max.
Beads weren't big, and went into the kiln nice and glowing, so they definitely didn't get too cool. The instant cracking makes me think it was a major incompatibility issue somewhere along the line.
Any ideas what the cause was?
I've heard that the CiM transparents hate being encased, maybe some of the opals are just as fussy? What a shame though :(
I have had that with Chalcedony, I tend not to encase it.
Ah ok, thanks. Good to know that Chalcedony is a fussy bugger - I'll avoid encasing it from now on then ;D Pity, as they were a nice colour - but at least I realised before I'd made the full set.
I always seem to get cracks if I use CiM with any other glass, I have been told in the past that the annealing temperatures can vary within their range which might explain why they aren't very compatible?