Homebrew PCBs

El Cheapo Hydrometer

Here is an idea: Use a small test tube with a few lead fishing weights at the bottom for a hydrometer. Seal the top, drop it in the etchant solution when it is at ideal density (or prior to first use), then mark off the float line with a permanent sharpie marker.

I'm thinking that would provide sufficient information.. since you really don't need to know the actual density value.. just wether it is too high or low.

~Rolan





--- In Homebrew_PCBs@yahoogroups.com, adam Seychell 
> 
> I've been playing around with cupric chloride solutions, trying different acid 
> and copper strengths, and found that the recipe described on Rex Allers cupric 
> chloride etching web page is far from optimum. If the copper concentration is 
> greatly increased the etch rate can triple. I have to buy new hydrometers 
> because the density is well above 1.2 which is the highest I can currently 
> measure. I'll let you know how it goes.
> 
>