> >Just tried the brushing-with-sponge technique, with excellent results.
>
> Well, maybe I should give ferric chloride a try then. It would avoid the
> rust problem which I only recently learned about, is probably safer to use
> (there aren't any fumes with ferric chloride, correct?). Do you just wash
> off the sponge in the sink afterwords?
Ferric Chloride will rust things too.
It stains most anything it touches.
Works best when Heated.
Do you have any metal in your Drain? Ferric Chloride eats metal.
Other than after etching it has copper disolved in it putting small amounts down a drain is not too bad, flush it with plenty of water. Ferric Chloride is used in Waste Water Treatment. But after you etch your boards it will have copper in it which is not all that good to go down the drain.
Ben