Depends on lots of things.

[Stephen Richard]

Depends on lots of things.  Three of them are:

Thickness of the piece – 3 & 4 mm typically does as you describe.

Heat work – each kiln has its own characteristics so it is not possible to be categoric here.  For some kilns 795C would not be hot enough, for others too hot.  For some ramp speeds it would be too cool, and for slower ramp speeds it might be too hot. 

Separator – Different separators have different characteristics.  Batt wash can be the smoothest separator if properly prepared, but will react to too hot or too long top soaking temperature.  Ceramic fibre paper often leaves little needles on the edges, but are easilly dealt with by use of a diamond smoothing pad.  Thinfire (a Bullseye product) is least likely to leave needles, but does under some cirucmstances.

As you don’t indicate your ramp speeds or soaks, it is difficult to give specific answers.

 

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/   and  http://www.glasstips.blogspot.com/