MFP

I did as you suggested and made up three samples with 50 colemanite and 50 of each sample. The colemanite had more chips from the can than I realized in it--so there will be some brown spots but that won't change the major chemical reaction significantly. I also made up three samples of that glaze PeterH posted. The reason I have to do another bisque is because I did not have all the clay samples for testing glazes ready. I had gotten some more  cone 6 bodies since I did the original bisque. So, should be very interesting.  I had also made a lot of little bowls and cups to test things like those above that I thought might make a mess.  I bought some kiln wash from a local vendor....it disturbs me....it's not the silica/alumina wash I am used to. So I didn't want to risk having to grind shelves. 

Thanks for all your input. As soon as I have those fired samples, I will post them! 

Epk, calcined epk plus alumina hydrate makes a great wash. No telling what's in commercial kiln wash.

Looking forward to seeing your results, hopefully you will have some answers!

Thank you for getting back to me!  Finished the bisque last night. Unfortunately blew out my knee again and have to stay off it today. I am hoping to finish glazing tomorrow and starting to load. 

Since this little electric is so old, I have been closely monitoring the fires to make sure it shuts off...and so far it has been just fine....with two 04 fires. Any idea how much longer I should be paranoid?