Alan DuBoff
>Pedder,

I just do not see the difficulty you elude to, and akin this very much to a chisel, for instance. Most folks do not grab a chisel and automatically learn to freehand sharpen on a stone, but they do develop that skill rather quickly.

Not knowing how the person attempted to sharpen a 15ppi saw, it's hard to comment, but proper lighting, being comfortably seated, using the proper file, and even magnification could each play a factor in the equation.

This is not rocket science after all...

Regards,
Alan