Can you perhaps elaborate a bit on this ?
Example of your soak cycle etc if you put in an investment after 2 hours hardening time versus if you are having a flask out for say 8 hours?
If its only been sitting for 2 hours, would you the ramp it to arnd 150 degrees C for a couple of hours before raising the temp?
Whereas if you let it dry for longer you can put it in a hotter kiln ?
Just had Peter Johns (Inventor of Argentium silver tell me following), after i had exactly what @arkaysilversmiths refered to.
“What happens is the outside of the investment dries first when it is allowed to stand for a long time in air. When the outside dries it seals the outside surface of the investment. This then traps the moisture inside. When the heat comes on, the water inside is turned to steam and the steam cannot escape. The pressure of the steam cracks the mould. Only allow the investment to reach its green strength about two hours and then start heating. This is where the 150°C is important and it should be done for several hours. It draws the moisture out slowly from the middle of the flask without sealing the exterior surface. I think the roughness of you casting is also caused by the water boiling inside the mould and roughening the surface of the investment.”
Best regard William