Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

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.

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) wasn’t aware of the properties of HCl…
>
>If there’s no other (practical) way of reduction, I’ll have to find out if it’s 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]
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>