|Monthly Tech-Tip |
Left is L4410K, right is L4410L. Very similar, but L has 5% more dolomite. And these cone 6 glazes work well, G2934Y left and G2936A right. These are slip-cast pieces, the walls are not super thin, but the straight-sided shape makes them more susceptible to warping and buckling. This effect can also be achieved using talc bodies, but they have the issue of being brittle, volatile, bloating and not fitting glazes. But both of these pieces have excellent fired strength at cone 6, they have a porcelain-like surface. Of course you will need to test shapes, adjust dolomite content and control firing temperature carefully to be able to do this with consistency. If you are near a Plainsman Clays distributor, they made a test run of L4410L (as the new L213), boxes are available for order. If not, you can mix your own.
Warping happens during the firing of ceramic ware when there is a high degree of vitrification and inadequate measures are taken during forming and firing to prevent it. Unexpected warping often happens with unstable shapes and over firing.