I'm getting ready to move approximately 40 feet of 1/2" copper pipe for the cold water line in by basement. With the price of copper rising is it ok to use the old pipe? The copper was installed approximately 40 years ago. Thanks. SKennell

Our bathtub has two faucets for hot/cold water. These appear to be original to the house (1920). All pipe used is galv, of course. The back of each valve has one inlet (union) from water supply, one valve-controlled outlet (threaded) to bathtub, and and one always-open outlet (union) to shower---shower has separate set of controls. (I would post a photo but I'm not allowed to do attachments yet.) I am doing some work on the shower and I need to disconnect the pipes that go to the shower. So I need to detach the pipe from the valve by unscrewing the union, then later put that pipe back onto the valve using the same union. (Obviously, I can't use a fresh union, the female side is on the body of the valve.) Is this likely to work, or is there a high probability that this union will leak? I could also cut the pipe rather than undoing the union, but then I would not have any threads at the cut end. I am not enough of an expert to know this...are there any reliable compression fittings or other methods that could be used to connect to the cut end (i.e. unthreaded end) of galv pipe? This is in-wall piping so it has to be very reliable. Many thanks for your help,