Ok ODT Brain Trust, I am in the midst of repairing a POL three eights connection from the LP tank to the regulator then house after it floated away during the flood. I thought I would be able to unsolder the compression/dog dick fitting but to no avail. My question is how in the hell is the copper piping secured inside of the fitting. I applied a LP and MAPP torch to it without any resolve or loosening. I finally found a double male pigtail POL as a replacement but need to know how this pipe is fixed into the fitting. Thanks 8. PS: no guesses.