Currently working on my new ribbon burner forge build. I put an initial layer of around 1/2 of Kastolite 30 on top of my kawool, after I let it dry to gently rubbed off the crumbly sections to see what was solid. I chose to add another layer since it seemed thin on the forge floor. Should I add another layer on the roof? It seems solid currently, and there's just a few small patches I have to fill in. I've heard that I could potentially cause issues with having two layers of Kastolite? Thanks!