I am looking at carving a river into my layout. Any suggestions how I would remove (easily and cleanly) a 1-inch deep "channel" out of my 2" foam base?
If it's clean you want, you're going to need a hot-wire cutter. Lacking that...it's going to be messy. Use a serrated kitchen knife, hacksaw...whatever is handy. Also keep a vacuum cleaner at hand to keep the mess down.
Good luck...!!!
I used kitchen knives and a wirebrush to do all my faom carving. Yes, it was a mess, but that is half the fun! Keep a shop-vac on duty and use it often.
Don't despair just yet....I used to cut out landing gear boxes out of foam wings for my R/C aircraft. I used my Weller soldering gun, and replaced the soldering tip with a pre-formed heavy gauge SOLID copper wire, about 12-14 gauge. It cut through foam like a hot knife through butter..!! Maybe you could rig something like this up to help you cut down on the mess...!! Just don't press the trigger for too long...the gun might give up the ghost....
Do you really need smooth cuts? To have a little texture is not a bad thing. And any roughness could be filled in with spackle or sculptamold. If you sprinkle dirt or sand on, and then your ground cover, you'll be okay. Like I mentioned, I used a wire brush for some of the shaping and it worked pretty good. It left some texture in the foam, but to me, that is a good thing.