[TowerTalk] Brown colored galvanized surface?

[Mark, K5ER]

He Steve,
         Here in the Gulf South, sometimes on vertical tower but pretty 
often on horizontal sections waiting to be stacked, that brownish haze 
appears. Mostly, it is associated with proximity to hardwood trees, 
particularly Oaks. The galv surface is rarely compromised underneath. Comes 
off fairly easily with a pressure washer, but sometimes, when its been 
there for a few years we need to use something like a milk can brush. 
Everybody remembers what that is, right?

73,
Mark, K5ER


>Howdy, TowerTalkians --
>
>     On lots of old galvanized towers sometimes you wind  up with a brownish
>colored surface. Can anyone tell me what it is? It's not rust  but
>something else. Just curious. Tnx.
>
>Cheers,
>Steve     K7LXC