RE: [VACList] Stainless screws in aluminum

[John Sellers <sellersj@xxxxxxxxxx>]

Ed,

I agree.  Al's point about the galvanic potential of stainless steel
versus aluminum is true as far as it goes, but it's more complicated
than that.  Stainless steel resists corrosion by forming an adherent
oxide layer and I suspect that this greatly reduces galvanic activity as
well.  Generalizations are hard to make because there are many alloys of
stainless and the alloy may not be specified by the hardware seller. 
Also the screws may or may not have been "passivated" after fabrication
(by dipping in an oxidizing acid bath to accelerate formation of the
oxide layer).

One thing I can say for sure is that when I was working at the Naval
Avionics Facility (about the time many of our Airstreams were built!) we
used stainless steel hardware in aluminum equipment all the time,
including stuff that had to pass MIL-STD-810 salt spray tests.

Bottom line is that I am using stainless steel screws in my Airstream
unless I see signs of galvanic corrosion.

Best,

John Sellers
1960 Pacer
Dayton, Ohio