last year I installed some cedar siding using galvanized finished nails. I sealed the siding with and transparent oil finish. I am seeing some minor rust stains from these holes now, is there anything to prevent this in the future such as putting putty over the holes?. I just put up a fence and to facilitate it I used my nailgun to install finish nails to hold in place until I could go back and put screws in. now Im wondering if I have to pull all those boards and pull the nails out to prevent rust stains.
With an EGalv nail it is going to rust sooner or later if its the HD Galv you will get black circles and runs below the nail its not rust just a chemical reaction. You should replace with stainless fasteners if you can.