<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
>>
Dear N295VV aka dj - I think it was me under the heading of "Corrosion due
to dissimilar materials" that posted the listing galvanic interactions.

Nice post by JonWilcox regarding the galvanic issues. Thanks Jon !

FAA Advisory Circular AC 43-4A - CORROSION CONTROL FOR AIRCRAFT is a VERY
comprehensive document on the subject of corrosion. It has a few
interesting things to say such as:

Galvanic Corrosion. Galvanic corrosion occurs when two dissimilar metals
make electrical contact in the presence of an electrolyte. The rate which
corrosion occurs depends on the difference in the activities. The greater
the difference in activity, the faster corrosion occurs. For example,
magnesium would corrode very quickly when coupled with gold in a humid
atmosphere, but aluminum would corrode very slowly in contact with cadmium.
The rate of galvanic corrosion also depends on the size of the parts in
contact. If the surface area of the corroding metal (the anode) is smaller
than the surface area of the less active metal (the cathode), corrosion
will be rapid and severe. When the corroding metal is larger than the less
active metal, corrosion will be slow and superficial. For example, an
aluminum fastener in contact with a relatively inert Monel structure may
corrode severely, while a Monel bracket secured to a large aluminum member
would result in a relatively superficial attack on the aluminum sheet.

Ted Stanley - A&P-IA
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>