Homebrew PCBs

Roland F. Harriston wrote:
 >
 >
 >
 > Repeat..............
 >
 > Don't use metals around Ferric Chloride.........period.
 >
 > Roland F. Harriston, P.D.
 > *********************

Serious question. How far is the minimum safe distance from metals where 
ferric chloride can affect them? I mean just the fumes and not a direct 
spill or slash. Does the Muriatic-Hydrogen Peroxide require the same 
rule exactly or is ferric chloride the worst one?
Thanks,
Dave