Aron;
It depends on conditions. Dissimilar metals will exhibit electrolytic
corrosion if you're running water, methanol, etc. or if other liquids such
as used oil or contaminated fuel have a bit of water or acids in them. It's
a problem similar to running coolant in a cast iron block with aluminum
heads or radiator-- you need a corrosion inhibitor if the fluid is water.
Steel adaptors generally have more of a rust problem than electrolytic
corrosion problems; stainless adapters generally are preferable-- if you can
find them. The anodize finish on AN fittings give them some measure of
protection against electrolytic corrosion as the Type II anodize finish is
an electrical insulator (a very thin layer, though) and if current can't
flow between dissimilar metals, electrolytic corrosion won't take place as a
result of that joint. Corrosion can also be local-- not depending on having
a bimetallic joint; it depends on the alloys.
If your gas & oil is kept clean (free of contamination), you should be fine.
Regards, Neil Tucson, AZ
-----Original Message-----
From: atrav [mailto:atravis@spacey.net]
Sent: Tuesday, October 07, 2003 8:49 PM
To: LSR list
Subject: Aluminum AN fitting corrosion
Should I worry about electrolytic corrosion between my aluminum AN fittings
and their steel adaptors? Or anything I should do to lessen it? FWIW they'll
be for gas and oil lines.
-Aron-
|