Homebrew PCBs

A hydrometer is floating already....

>
> Also add some hydrometers to your shopping list to cover the
> range 1.00 to 1.30  I find hydrometers with 0.10 range are plenty
>   good. Standard laboratory hydrometers have a range of 0.05.
>
> Looking at the commercial CuCl etchant (
> http://www.oxfordvue.com/TechInfo/how_does_it_work.html ), they
> run at  s.g 1.35 to 1.4 and have about 220 g/liter of copper.
>
> I think this is too high, I found 1.25 to 1.30 better for room
> temp etching. CuCl2 etching without chemical oxidizers (H2O2,
> Cl2, NaClO3 etc) should etch 35um copper foil in 20 minutes at
> 20\ufffdC with bubble agitation. Keep HCl plentiful.
>
>
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>