TIN OXIDE 1 lb
TIN OXIDE is a popular opacifier for ceramic glazes. Due to it’s high cost it is not nearly as widely used as Zirconium Silicate Ultrox) Tin Oxide must be sieved when added to ceramic glazes as the raw form will usually be bit gritty and will not disperse into a glaze simply with mixing.
Here is a list of comparisons between Tin Oxide and Zircon:
-Like zircon, tin melts at very high temperatures and thus does not go into solution in typical glaze melts.
-Zircon will stiffen the glaze melt more than tin.
-Zircon will likely produce a harder glaze surface.
-Zircon will reduce the thermal expansion of the glaze more than tin.
-The quality of the white color is different (tin tends to be more of a blue white, zircon a yellowish white).
-Tin is very expensive, this is likely the main reason for its much more limited use as an opacifier today.
-Zircon tends to have less of an effect on the development of metal oxide colors (e.g. tin reacts with chrome to make pink).
-If gloss is an issue, silica might have to be reduced to compensate for the silica introduced by a zirconium silicate opacifier being substituted for tin.
-While there are other products that produce varying degrees of opacity, none are as neutral and non-reactive as tin and zircon. Other opacifiers also tend to variegate the glaze.
-Tin does not normally opacify in reduction firings.
-Tin can act as variagator in glazes.