MICHAEL D

I was pouring sterling, some earrings, rings,and pendants. The plaster folks recommendedat least 24 hrs to set and cure out the water content I gave it 72 hrs and they were the light grey specified pre burn. The castable resin people recommended the 13 hr staged burnout. A very gradual heat and also cool down. I was so sure I followed the procedures to the letter. I checked the kiln and temp control appears To be accurate. Now a wax burnout is a lower temp and shorter duration that required for the resin casts to burn out. I suspect that things would have gone better if I was not using the resin but really dont know. I'm looking for plasters that are specifically designed for the long hot burnout. I guess I was looking for someone who might have some experience With these types of issues and could recommend anything that would get me better results. Was a lot of work to end up in disaster on the last step... Gonna try again this weekend probably with a less aggressive heat cycle, not confident I'm not wasting more time and materials but to hard headed to quit

i did my first lost wax burnout and pour,... first in 18 years.i was so excited and thought i had done my research well enough. turns out i was very very wrong. i had three flasks 4x6 and one 3x4 flask. 1400 slow ramp burn walked up to 1300F and crashed to 900F before pour. long story short... all of my plaster shrank a lot in the flask and my plaster cracked to pieces ruining my molds and my afternoon. it anybody would like to guess at what i did wrong and make some suggestions i would be glad to take advice or listen to explanationsof what all i might have done wrong. side note i was using green wax sprues and castable resin molds. plaster used was ultracal 30.. when i examined the broken pieces all of the detail looked amazing and seemed to be a clean burnout with no residueleft over. i assume that the work would have come out nicely if i had the heating program dialed in but the shrinkage was quite excessive. any thoughts or advice would be greatly appreciated