[Ferro List] electrodeposited galvalume vs galvanizing

[twobends at charter.net]

You'll note in all these posts on hydrogen generated voids there is no mention of the actual 
coating that is applied to your steel.  The last galvanized screen I purchased took a while to 
hunt down, apparently due to the EPA and globalization most of the screen and great deal 
of the wire meshs are made in China.  It looks like well oxidized dipped zinc to me. 

   A purchase at Home Depot recently is clearly electro-deposited and has the bright lustrous 
appearance of galvalume which has a longer life for it's bunny repelling use over regular 
galvanizing.  With a chinese suppliers specs not being readily obtainable, it could be very 
hard to distinguish galvalume vs galvanizing on wire.  It's much easier on sheet metal.

   Powdered aluminum was the ingredient used to make cellular concrete by the Turkish 
professor who used to post here.

  Galvalume is promoted to last much longer than straight galvanizing, hence the finish 
stays brighter due to the aluminum in the alloy coating.  LESS OXIDATION to provide a 
barrier during concrete curing, and the aluminum itself might react even though alloyed and 
not in a powdered state.  Indeed, aluminum powder has a very fine oxide layer on it that is 
very stable, yet ready to react and form hydrogen in cement slurries.

  Haven't checked on this, but it's a thought.

Alan