I bought both my Brents used. My CXC I have had and used for over 40 years. Changed the bearing last year. While my main wheel was down, I bought another used model c from a handbuilder. It is quick and responsive and lighter to move around the studio..
Ironically, both our countries are in the throes of elections. In Canada, education is a provincial mandate. This means that the federal gov't under Stephen Harper cannot cut support to arts education across the board. This did happen in British Columbia with many teacher strikes and protests last year.
I do not in any way wish to come across as smug or superior about our 3 party system. We have 8 weeks to go. The big issue here is health care and balancing the budget.
This is just spitballing, but...
Given that one of the main ingredients to a cone 6 floating blue is an iron bearing clay (Alberta slip) plus some frit and rutile, perhaps it's a reaction between the tan and red (iron bearing) clays and the glaze. Especially since the white slip is showing green.
I don't know about the iron. I don't think so-it will just make it dark.
I am looking at the wollastinite fluxing the copper.