How to Switch from Cast Iron to Copper Piping? Switching from cast iron to copper piping for residential hot water can be done by the home handy-person. Copper piping retains heat and resists corrosion much better than cast iron. Follow these steps to replace cast iron piping with copper.Tools and Materials You Will Need * Red brass (85% cobre, 15% níquel) piping, 12-pie … [Lee mas...] about Switching from cast iron to copper piping