Homebrew PCBs

On Wed, 03 May 2006 02:42:02 +0200, Bill Westfield <westfw@...>  
wrote:

>
> I was hoping to avoid titration-like measurements, but perhaps this
>
> is going to be impossible, basing replenishment on color, opacity,
>
> and the fact that I though aeration-based replenishment would just
>
> stop when it was done (and some free HCl isn't so bad), but I guess
>
> I can also drive away all the HCl...
>
>
> BillW


It is possible if you simply add HCl when you see a bluish tinge or  
etching slows down, and regenerating does no longer work.

I promise you the blue is lack of HCl, no fancy chemical formulas here,  
but been there, seen that.

Measuring molarity is dead easy however and you don't have to wait for  
trouble.

ST