rigand

Thanks for the reply! I'll be sure to try that.

I made a foundry out of ceramic wool and Kast-o-Lite 30 a while ago, but I didn't have quite enough to fill the foundry all the way to the top. There is a gap of approximately 2 inches at the top. I have already cured and fired the foundry and used insulating firebrick to fill the gap, but the bricks are now falling apart and I'd like to replace them with more Kast-o-Lite 30. Is there anything I should be aware of before I add the new mix? Will the new mix bond with the old, or should I expect a seam? If so, will it cause problems? Any advice is appreciated. Thanks!