Is galvanized steel totally incompatible with cedar, even when only touching on the surface?

Question

I'm building a cedar picket fence attached to 2 3/8" chain link fence style galvanized steel posts using galvanized post brackets like these. I know that there are a lot of material incompatibility potentials here, so I want to make sure I get it right.

Two questions:

1. I know that galvanized fasteners corrode in cedar and cause ugly stains, but will it be a problem to have galvanized brackets simply touching the cedar rails on the surface? Should I "downgrade" to spruce/fir/pine rails in order to reduce corrosion of the galvanized hardware that will be touching them, or physically isolate them from each other with something?

2. If I use stainless steel screws to affix the rails to the galvanized brackets, will that create a galvanic corrosion potential? (the galvanized brackets will be the anode)

Answer 1

Yes, to both. The cedar will last for decades and your hardware should too. Simply isolate the galvanized from the stainless and cedar, but definitely don't trade the cedar for some much lesser grade wood. Don't get talked into hot-dipped fasteners, stainless is the only way to go.

Buy thick fiber or plastic washers or even use cut-up pieces of tar-paper, rubber, roofing shingles, milk jugs or soda bottles. Of course, the more UV resistant the better, the exposed cheap stuff can be trimmed or spot painted after installation for UV protection.