Ceramic kiln for fusing glass

[CrazyKiln]

I have just started glass fusing (using Bulls Eye glass) and I'm firing in my ceramic kiln. I have just fired some coasters and the edges are a bit wavy. Any ideas why?

[MeadMoon]

Uneven cutting?  More or fewer layers of glass around the edge?  How many layers were you using and did you have any inclusions.  A photo of your coasters may help with troubleshooting.

[Glyn Burton]

What is your firing cycle, perhaps they are a bit over fired?

[CrazyKiln]

I'm sorry to have ignored your replies - a combination of illness, computer problems and busy business have kept me away. Thank you for your suggestions. I have done a few more test firings and have a much better understanding of why the original coasters had such wavy edges. Thanks for your help.