Originally Posted by
machinist42
Filiform corrosion aka "filamentary corrosion" or "underfilm corrosion".
I politely beg to differ with the dire prognosis suggested previously, as I've generally found filiform corrosion to be readily checkable with an acid bath, I prefer phosphoric. though I suppose oxalic would work. In my experience filiform has been superficial. I'm not saying it can't erupt from within the tube, but I haven't seen that often. Mostly it's sweat spawned.
Absolutely correct in many cases, tx for the correct terminology.
Again as Doug alluded to it can most certainly be a scourge and kiss of death albeit maybe a slow one. Caught in time, not that big of a deal, left unchecked it can screw up a lot of paint which I would think a good idea to avoid.
Jim Merz treated his frames by complete contaminate removal and zinc chromate? primer before Imron paint was applied by Virginia for the infamous PDX rain. He is adamant that frames be stripped, treated and repainted when this is found, Between him, Mr. Fattic and many others, I'll go with the Master framebuilder's on this.