The fluid in the etchtank removes all copper
exposed to fluid. It damages most metall objects as
sink and other items. In order to activate movements
in the fluid pressured air is inposed in the bottom
of the tank as in a fish tank. In five to ten minutes
all cupper on unmasked areas is removed.
Copper is around 20 - 50 micro mm thick. Fresh fluid
is transparent. As process is going on the copper
colors the fluid blue as a new chemical stoff.
And is no longer usabel for etching.
When ready it must be washed in water to remove
all etching fluid rests.The fluid should be at
50 C degress constant heat.