News for hackers. Stuff that matters.
Re:Squink Lets You Print a Circuit Board for the Price of a ... by altcognito on Tuesday July 15, 2014 @10:31AM (#8036614)
> and it's so easy that a child can do it.

...

> then using a corrosive liquid to etch away the unwanted copper

Do I then dump the wastewater into the stream in the backyard?

Re:Squink Lets You Print a Circuit Board for the Price of a ... by jdietrich on Tuesday July 15, 2014 @11:39AM (#8037057)
Ferric chloride etchant can be safely poured down the drain if it is neutralised with washing soda and filtered to remove the precipitated copper. Alternatively, it can be mixed with a proprietary neutralising compound and disposed of as solid waste. The etchant itself is quite harmless; It is the copper ions which pose an environmental hazard.

Many alternative etchants (e.g. cupric chloride) have an indefinite working life and so pose no disposal issues.