SASH, the line is shallow buried running up hill about100 feet. No place to bury heat tape and a long way from power. I was wondering about my pressure washer an feeding it with some hot water from 5 gallon jugs. a, then shooting it up the line.
Boy that is a bit of a pickle. Sometimes when we are out on construction sites and need to draw frost, we lay down a layer of coal about 6" thick and get it burning. It works really well. If you had access to some coal and know where your pipe is, I'd lay it down a strip of coal about 2' wide and light it. Don't know how practical it is but I bet it would work.
"Red meat is NOT bad for you. Now, blue-green meat - THAT'S bad for you!"