How do I remove old plumbers putty from between 2 pipe joints that are stuck together.?

Question

the joints are 40 years old, and on a portable air tank. In order to use the tank I have to be able to break the putty and remove the pipes. I've used a pipe wrench and it won't break free, it won't disassemble. I need to soften the putty so the wrenches will work. Is there a solvent that will work?

Answer 1

Heat  gun..........................

Answer 2

You need to use heat. One of those propane torches that go onto the bottles that hold about 1/2 pint.

If there are connections close to it you don,t want to damage wrap them in a wet cotton cloth. that will stop too much heat getting to them. Take the connection off while still hot.

Answer 3

...or copper torch

Answer 4

The solvent is Liquid Wrench.  It should soften the putty  sufficiently to break the joint without damage to the tank.