Homebrew PCBs

Are you sure you didn't slip a decimal point somewhere? This is a very concentrated acid, much more than you would need for PCB etching.

A saturated solution of HCl in water is 37-38%. There is no such thing as 40% HCl.

Bruce


--- In Homebrew_PCBs@yahoogroups.com, "Roger Blair" <Roger.Blair@...> wrote:
>
> I wish to prepare some HCl/H2O2 etchant, and I have 10% HCl. (10% HCl is $5 per gallon, but 40% HCl which is what I need is a lot
> more expensive)
> 
> The solution as I see it is to reduce the 10% HCL solution to 40% concentration. I am thinking of using a Pyrex container on low
> temp lab hotplate (100°?) to `boil' off the H2O. (outdoors)
> 
> Since I know next to nothing about chemistry, not to mention whether this technique would actually produce what I need, I would like
> to get some input here.
> 
> I have a general understanding of safety issues in handling chemicals, and wish to do this in a reasonably safe manner, BTW…
> 
> (I will be working with no more than 10 to 20oz. of 10% solution at a time, to minimize any environmental impact to me, and the
> surroundings.)
> 
> Any advice would be appreciated.
> 
> Thanks,
> 
> Roger
> 
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