"bryanska" wrote in message
oups.com...
Hey,

Does anyone have any ideas on how to cut a 3-inch wide and 1-inch deep
trench into the face of a panel of EPS foam insulation?

It should travel vertically up and down the 8-foot high face.

Any ideas welcome.

Hot wire or hot knife is what is done on job sites. You can use a soldering
gun and a template to guide it.
http://www.wind-lock.com/public/icf/2qc_hot_knife.asp

Open the window and put a fn as it will stink and smoke a bit.

You can use woodworking tools, but then you will have dust all over.