I wanted to work on my K2.
As luck would have it a nor'easter blew in, a real blizzard and my 1972 CB750 K2 was buried.
The temperature dropped to minus 29 overnight.
So the next day I shoveled it out and brought it in to my warm shop. I took my rubber mallet to hit the frame to knock the snow off and to my surprise all of the dirt and grime shattered like glass and fell right off along with the snow and ice. This left a smooth clean surface. I was able to warm up the frame and paint it that day.