I have used caulk to seal a small opening around a copper pipe as it passes through an exterior wall. I purposely did not use silicone because I’ve seen it can be corrosive to some metals. I tried a new high end clear selant because the area will be inaccessable for retreatment. However, a day later I checked the sealant and instead of being clear it had a bluish color that would indicate a copper corosive reaction. It won’t be easy to replace the sealant. Does anyone know if this is serious; is this a surface reaction or would it continue to degrade the pipe over the years?
There are basically two types of single part RTVs. Acedic Acid and Oxime/Alchol cure. The Acedic Acid one is corrosive the other is not. Both cure thru evaporation. Once the cure is complete the corrosion ceases. As long as you have not trapped the evaporating gas inside something like a sealed container it will disapate harmlessly. If this is the case I would not loose any sleep worrying about corrosion.