--- In
Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...> wrote:
>
> morriso2002 wrote:
> >
> > Thanks to everyone who replied - particularly with the news that Farnell
> > still sells FeCl3. It looks like the hexahydrate, but that's OK. It
> > seems I will be able to continue using my favourite etchant for a while yet.
> >
>
> Any particular reason you want it without water molecules ?
> You have to add water for it to etch anyway.
>
> People prefer to buy and sell a near saturated 40% (wt) solution because
> it is easier to store long term.
I (used to) think it's easier to store the anhydride. I started off that way a long time ago and like the exothermic reaction when it dissolves - helps to keep the solution warm. I have used the hexahydrate too and it's fine too of course :-) I tried ammonium persulfate once but there's no comparison.
Morris
>