I had a 2 gallon tank of hot Ferric Chloride getting
ready for etching some boards - and a student - naturally -
stuck the end of a Electrolytic capacitor - Al can - into the
acid to see what would happen. The rapid reaction startled
him and he dropped it into the tank. That was a messy
cleanup and the acid was reduced to trash.

Martin

On 11/24/2010 8:20 PM, Lloyd E. Sponenburgh wrote:
fired this volley in
:

What was the nature of the fumes? Hydrogen on the acid side?

I have never tried etching aluminum but this gives me some ideas...



It was hydrogen, as you guessed, with liquid mist incorporated.

Aluminum may be etched with a number of substances. Bubbles of gas
liberated during etching have both good and bad effects. They stir the
liquid, accelerating the process, but they also promote undercutting of
any resist you apply.

Ferric chloride does an amazingly good job on aluminum. (yeah, the same
stuff you use to etch copper-clad pcb material.) But you do have to
agitate it, for lack of stirring bubbles.

LLoyd