Material in contact with aluminum - stainless or galvanized?
Material in contact with aluminum - stainless or galvanized?
(OP)
Hi,
Need some advice. We are specifying a racking system for PV modules (sheltered outdoor application). The basic construction is aluminum blocks (~1"x2"x2") bolted to a rail. The question is whether to use a HD galvanized rail or a stainless rail. The environment is rural but might have elevated SO2 levels because this is on the roof of a winery. The galvanized rail obviously will not last as long as the stainless (though the Zinc Coating Life Predictor indicates adequate life) but I am concerned about the galvanic couple. Also the aluminum block has two large (3/8") 18-8 bolts through it, the manufacturer claims this will not be a problem.
Thanks for the help!
Need some advice. We are specifying a racking system for PV modules (sheltered outdoor application). The basic construction is aluminum blocks (~1"x2"x2") bolted to a rail. The question is whether to use a HD galvanized rail or a stainless rail. The environment is rural but might have elevated SO2 levels because this is on the roof of a winery. The galvanized rail obviously will not last as long as the stainless (though the Zinc Coating Life Predictor indicates adequate life) but I am concerned about the galvanic couple. Also the aluminum block has two large (3/8") 18-8 bolts through it, the manufacturer claims this will not be a problem.
Thanks for the help!





RE: Material in contact with aluminum - stainless or galvanized?
RE: Material in contact with aluminum - stainless or galvanized?
Also, while SS vs. alum/zinc/steel couples are generally to be avoided like TVP points out, your area rations are helpful (huge anodes and small cathodes), so I wouldn't expect quick corr. failures. But if you can insulate the SS it's better.