[Ferro List] Passification of galvalume???

[Keith B]

Hi Alan

Amongst theoretical possibilities there's also Galvaneal, electroplate 
and sheradizing.  Any might be met with on some embedded object, but 
hardware store or similar vendor hardware cloth mesh is most likely (at 
least notionally) simple hot dip plain zinc.  (There's always Chinese 
quality control...)  From a description, what Tom used was the thickly 
coated mesh that I've sometimes seen described as rabbit wire.   
(Coating noticeably beading at wire crossings)  I've had that crack and 
peal on bending, and memory of the fractures make me now suspect 
crystallization.  That got me to wondering whether a manufacturer might 
use some low alloy and dip when it's in the solidus state to visibly 
increase deposit thickness.  Does this sound a possibility?  Also, as an 
expert in the area, can you remember any warnings or notes as to what 
may be encountered other than aluminum and zinc when welding 
"galvanized" items?

kb

twobends at charter.net wrote:
> Keith has been commenting on G60 galvanising as though that it was the coating that 
> caused the problem.  The fellow may well have used mesh with Galvalume instead of 
> galvanizing on it.
>
> GALVALUME is 55% aluminum, 45% zinc.  Aluminum is a hydrogen gas generator.
>
> Alan
>
>