On Tue, 19 Jan 2010 10:06:01 -0500, you wrote:
>On Mon, 18 Jan 2010 23:15:29 -0800, you wrote:
>
>
>In California, you can't buy concrete cleaner (approximately $6 to $7
>per gallon) at Lowes. I'm sure that Home Depot has it as well.
>
Need question mark after Lowes.....
H.
>Kmart or Walmart has H202 for about 1.39/quart or so. The mixture
>works fine for me.
>
>Note that when initially mixed, works MUCH faster than FeCL3, so you
>will want to watch the boards carefully.
>
>Use face mask.
>
>Harvey
>>Hal,
>>
>>I (obviously) wasnt aware of the properties of HCl
>>
>>If theres no other (practical) way of reduction, Ill have to find out if its possible to buy from a chemical outlet as an
>>individual here in California.
>>
>>Thanks, and Regards,
>>
>>Roger
>>
>>
>>
>>From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of halamander
>>Sent: Monday, January 18, 2010 10:25 PM
>>To: Homebrew_PCBs@yahoogroups.com
>>Subject: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40%
>>
>>
>>
>>
>>
>>Roger,
>>I think you will find that this is not a particularly effective technique. HCl in its native state at room temperature is a gas,
>>what you purchase is an aqueous solution of it. I think you will drive the HCl out of solution before you evaporate much of the
>>water, thus leaving yourself with a weaker soln.
>>Hal
>>
>>--- In Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.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
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
>>
>>
>>
>>
>>
>>[Non-text portions of this message have been removed]
>>
>>
>>
>>------------------------------------
>>
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>>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>>
>>
>>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
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>
>
>