2.25 lbs Soda Ash2.75 lbs Baking Soda
4 lbs whiting
Enough wood shavings to fill a 5-gallon bucket halfway up
Enough water to make a tuna-salad consistency
This is the mix I add into the ports, on a length of angle iron, starting about Cone 8. I often get the question: what does the whiting do? A fair question, as it won't vaporize, so doesn't contribute to the glazed surface on the pots.
I can only tell you observationally, not chemically, what the whiting does: without it, the soda glaze seems less evenly distributed, and a whole bunch of it ends up on the floor of the burner channel. Which is not a good place for it, not only because it isn't doing any good, but because eventually it will eat away at the brick. I also periodically clean out the burner channel, and pour a fireclay/ alumina slip over the floor, to protect the brick. I am in no hurry to have to rebuild this kiln!