Homebrew PCBs

Maplins has the hexahydrate, I thought there was two types: 
hexahydrate and another anhydrous one?
Don't ask me if there is a difference, I haven't studied any chemistry
but on a website its said to use the hexahydrate not the anhydrous 
one???
This etching chemistry is complicated...all I want to do is etch 
small circuits in a little tub with the least amount of hassle with 
easy availble and reasonably safe chemicals (ie I don't want to wipe 
out a little part of swinton:-P)

PK

--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
> If you must use FeCl, don't get the pellets or powder.  Its 
> exothermic (I think this is the right term) when it reacts with 
water 
> and produces a lot of heat and splashing if you aren't careful.  
> Makes a gawdawful mess.  Nasty stuff.
> 
> I agree with Stefan, CuCl is a better way to go (cheap, easy 
> availability of components).  Even Ammonium Persulfate is better 
than 
> FeCl (no staining and doesn't generate heat when mixed with water) 
> though relatively pricey.