Carving the foam insulation blob into a mountain?

Any sharp long bladed carving knife will work, electric knife, specialty foam cutting hot wire knife, hacksaw blade - the list is endless.

A razor saw.

MELGAR

A seriated bread knife, worked great.

That foam will be hard in a couple of hours. It cures by chemical reaction, not dry time.

Not sure why you need to carve so deeply. I would have made the mountain closer to the shape you wanted, then just carved the surface to make it look like rock. I used foam board insulation for my mountains. I do most of my carving with a pocket knife. If I do need a deeper cut I use a fillet knife.

Thanks Guys,

It sounds as if I don't need a long razor blade type of knife,  but that a sawing knife like a bread knife or steak knife will do.

Happily, my blob isn't a big long-loaf shape, but has varied peaks and cliffs.  I just don't want it to have rounded edges, smooth surfaces or large knobs.

And Joe, that is one fantastic looking cliff face!

Mannyrock

olfa knife