Figure 10. Vinegar and Salt Etchant
of minutes. In the past, I used ferric
chloride to etch boards by placing
them into a bath of ferric chloride.
Even with agitation, etching a
board could take ten minutes or
so. The sponge and ferric chloride
method accelerates the etching by
continuously rubbing the surface with
a sponge soaked in ferric chloride.
The rubbing removes the oxide
layer that continuously builds up,
permitting the ferric chloride to get
to the raw metal and thus accelerate
etching. Instead of a tub of etchant,
a couple tablespoons is all you need,
which will make a bottle of ferric
chloride last for a very, very long time.
The technique is simple. Don plastic
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