Homebrew PCBs

Don't know the actual chemistry, but what happened is the Ferric 
Chloride actually etched the aluminum at a VERY fast rate. If you 
dip the aluminum into room temp solution and leave it for a minute 
or so it will actually start the solution boiling against the 
aluminum the reaction is so fast. Plus the part will get hot. Was 
just playing with this yesterday after doing some research on 
etching aluminum. Dunked a 1/2" dia aluminum bar about 6" long with 
about 2" of the bar in the room temp etch. Within a minute the other 
end of the bar was getting noticably warm. Washed off the scale and 
scum and measured. About .008" of diameter was removed from the bar. 
The resulting gray is the etched surface of the metal.

Tim 
A2Z CNC 
1530 W Tufts Ave Unit B 
Englewood CO 80110 

tim@... 
www.A2ZCNC.com 

USA made accessories for desktop mills & lathes.