They ran copper tubing upstairs, but never hooked onto it. The upstairs line looks great. The 4-5 inches outside underneath the camp looks like an older/tarnished penny. I was wondering if there was any prep work I should do it prior to hooking up a compression fitting to it and marring it with the main propane line? It's 3/8 in diameter. I don't want to sand it clean as it will lose some of it's diameter and strength. Would I be ok just hooking on to it and checking it for leaks?