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) wasn\ufffdt aware of the properties of HCl\ufffd >> >>If there\ufffds no other (practical) way of reduction, I\ufffdll have to find out if it\ufffds 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\ufffd?) to \ufffdboil\ufffd 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\ufffd >>> >>> (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 >> >> >> > > >------------------------------------ > >Be sure to visit the group home and check for new Links, Files, and Photos: >http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > >
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Re: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40%
2010-01-19 by Harvey White