"Stefan Trethan" <
stefan_trethan@...> writes:
> That looks like medical H2O2 there. I thought medical solution
> contained too much water for CuCl etching?
It's a 3% solution.
> Does the sink really drain to groundwater? I don't think any sink
> should drain straight to groundwater ;-)
It drains into the perimeter drain for the basement, hence the sign.
The pipe eventually ends up draining out in the woods downhill of the
house, which is technically groundwater. It's not ideal, but the
septic lines are a couple of feet higher than the sink - not that I'd
want that stuff in my septic tank. Tanks have living biomass in them,
you know.
Mostly I wanted a source of water (hot and cold). I use plain water
for my woodworking stuff also. I can also keep the water running
while playing with the chemicals, in case something bad happens I can
do a quick rinse.
As for the rest of the chemicals - even if I rinse the pcb's off in it
after etching, the amount of copper that goes in there is less than
what my copper pipes are putting into the ground, and we've already
got a ton of iron in the ground anyway. There is sufficient distance
between the outlet and other water systems to provide filtration.
To top it all off, my wife works for a company that does water
systems, and she says it's acceptable. The sign is mostly to keep out
woodworking stuff, like solvents, stains, paint thinners, oil
finishes, etc.