I bought a used 14x80 cold frame (hoophouse). It is assembled by driving a 1 1/2" OD piece of EMT into the ground. Then a sleeve of EMT (slightly larger) is screwed on to the top of the EMT that is in the ground. Then one end of the hoop part is inserted into the sleeve and then screwed on. I need to get this assembly apart but it is rusted together. There is a thin layer of rust on each pipe end that goes into the sleeve. Would you use penetrating oil and let it sit for while then pull it apart with a pipe wrench? Would it help to heat up the sleeve with a torch? Some of these came apart without much trouble once I could turn one piece independent of the other.