Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Dave <theschemer@...> wrote:
>
> Is there some simple but professional plans to build an etchant 
tank? I 
> mean with heater and agitation, not just a jar and manual labor:) 
Or is 
> one available that is professional but not too pricey? I seen one 
for 
> $50 and I bookmarked it. http://www.web-
tronics.com/lowcosetsysw.html  
> Is that worth the $$ or could I make something with aquarium parts 
> (heater, pump, etc). I was also planning on using ferric chloride 
as I 
> have a bottle from RatShack from when I started getting interested 
in 
> this some years ago. I know there are other etchants and comments 
are 
> welcome on whats best but I think other than the staining and 
inability 
> to see your boards progress, ferric chloride is probably as good as 
the 
> others??
> 
> Thanks,
> Dave
>


It has been my experience that bubblers and other agitation methods 
are not worth the hassle. The generally make it difficult to contain 
the etchant (leaks, spray, etc...) and require more echant be used 
than is really necessary. 

Floating the board on the surface of hot echant is almost as 
effective as the bubbles anyway. The removed material falls away as 
it etches clearing the way for fresh etchant to be applied to the 
next layer.

I would suggest a simple system of a metal pan of hot water on a 
stove or hot plate with a shallow plastic pan of echant in it. Pour 
in a little echant, just enough, then  float the board and check on 
it until you can see through from the top. For double sided, do one 
side at a time and tape the side on the top.