[Cob] RE: cob oven glazing

[Mary Lou McFarland]

I hadn't heard of using borax, but I know for working with kilns if there is 
cracking,or if you want to keep anything from touching and adhereing to a 
surface then you use kiln wash.  You can mix it thin as a paint on type 
glaze or mix it thick and use it to pack into cracks and repair the sides of 
your kiln wall (the firebrick).  Many kilns can fire in excess of 2000 
degrees F. so the kiln wash is pretty tough stuff.  It's been awhile since I 
ordered it but I would get mine very reasonably through Lou Davis Ceramic 
Supply.  You could also try Amaco (spelling?) which I think stands for 
American art and clay company.  It's fine stuff,so wear a face mask until 
you get moistened.