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2010-01-12 by David Griffith
Where can I find a decent etch tank setup in the US that I won't have to spend a fortune on? I'd like to get one of these: http://www.computronics.com.au/kinsten/et/ but the shipping is going to be a killer. Cereal boxes just don't do it for me. -- David Griffith dgriffi@... A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?
2010-01-12 by Stefan Trethan
Make it? Have a custom fish tank supplier make it? ST
On Tue, Jan 12, 2010 at 7:44 PM, David Griffith <dgriffi@...> wrote: > > Where can I find a decent etch tank setup in the US that I won't have to > spend a fortune on? I'd like to get one of these: > http://www.computronics.com.au/kinsten/et/ but the shipping is going to be > a killer. Cereal boxes just don't do it for me. > > -- > David Griffith > dgriffi@... > > A: Because it fouls the order in which people normally read text. > Q: Why is top-posting such a bad thing? > A: Top-posting. > Q: What is the most annoying thing in e-mail? > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > >
2010-01-12 by AA9GG
Not sure my post made it.... Here is one stateside: http://www.web-tronics.com/lowcosetsysw.html they actually have quite a few different ones. --- In Homebrew_PCBs@yahoogroups.com, David Griffith <dgriffi@...> wrote:
> > > Where can I find a decent etch tank setup in the US that I won't have to > spend a fortune on? I'd like to get one of these: > http://www.computronics.com.au/kinsten/et/ but the shipping is going to be > a killer. Cereal boxes just don't do it for me. > > -- > David Griffith > dgriffi@... > > A: Because it fouls the order in which people normally read text. > Q: Why is top-posting such a bad thing? > A: Top-posting. > Q: What is the most annoying thing in e-mail? >
2010-01-13 by Adam Seychell
David Griffith wrote: > > > > Where can I find a decent etch tank setup in the US that I won't have to > spend a fortune on? I'd like to get one of these: > http://www.computro nics.com. au/kinsten/ et/ > <http://www.computronics.com.au/kinsten/et/> but the shipping is going > to be > a killer. Cereal boxes just don't do it for me. > I'm afraid the hobby PCB market is too small to make etching tanks widely available and at low cost. You best to make it. If you are not far from a plastics supplier, then order some appropriate sized acrylic sheets (I recommend 4 to 6mm thick, 3mm is too week in my experience) and buy some solvent glue. Unless you have proper equipment you won't cut smooth enough edges for solvent gluing. Glue on some side stands (as shown above link). Buy a cheap aquarium 200W heater if your want to use persulfate. Keep the tank width under 30mm so the bubbles are forced to flow vertically. A wide tank is more difficult to get uniform bubbles. Most aquarium heaters are under 30m diameter, but check before you build. A bubbler is 1mm holes spaced at 20mm in PVC pipe running the *whole* length of the tank. Jam a block of rubber between this tube and tank wall or lay down a couple of stones to stop the tube from floating. Use largest air pump you want to pay for. Use plastic coated wire for PCB hanger. Let the PCB hang freely in the tank and provided you have sufficient air volume the board should randomly move about aiding etch uniformity. Keep at least 70mm of tank height above the liquid level. Adam
2010-01-13 by Roger Blair
Take a look at this for $55. Contemplating one of these for myself, as it will cost me half or more of that for materials, plus time to build. They claim a molded tank, which should be more reliable than DIY fabrication. http://www.web-tronics.com/lowcosetsysw.html Regards, Roger
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of David Griffith Sent: Tuesday, January 12, 2010 10:44 AM To: Homebrew_PCBs@yahoogroups.com Subject: [Homebrew_PCBs] decent etch tank setup Where can I find a decent etch tank setup in the US that I won't have to spend a fortune on? I'd like to get one of these: http://www.computronics.com.au/kinsten/et/ but the shipping is going to be a killer. Cereal boxes just don't do it for me. -- David Griffith dgriffi@... <mailto:dgriffi%40cs.csubak.edu> A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? [Non-text portions of this message have been removed]
2010-01-19 by Roger Blair
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]
2010-01-19 by halamander
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, "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] >
2010-01-19 by Roger Blair
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]
2010-01-19 by Stefan Trethan
The HCl will definitely boil out first (around 50C lots of it turns to fumes). ST
On Tue, Jan 19, 2010 at 8:15 AM, Roger Blair <Roger.Blair@comcast.net> wrote: > 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 >
2010-01-19 by lists
In article <hj3j88+7erb@...>, halamander <frog.aye@...> wrote: > 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. Certainly will. It's 40 years or so since I did any chemistry but I seem to recall "drying" organics with anhydrous Calcium Chloride, maybe it would work in this case. Being a Chloride it would not react with the HCl. However, even if it works how are you going to ascertain the resulting strength of your acid? Better to get the required strength, or higher, in the first instance. -- Stuart http://www.torrens.org.uk/ZFC/gallery/winsor.html
2010-01-19 by Adam Seychell
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) > You would end up less than you started with as others have commented. 30~35% (wt) HCl is readily available as brick cleaner/ pool acidfier here in Australia. Even sold in 250ml bottles up to 20L drum at some local hardware stores. Its possible to remove some of the water, but not practical. Normally, dry HCl is produced in an oven and then dissolved in water until saturation, of which you get about 35% acid at STP. Adam
2010-01-19 by ikc46118
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 > > > > > > > > > > > > [Non-text portions of this message have been removed] >
2010-01-19 by Harvey White
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\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 > > >
2010-01-19 by Harvey White
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 > > >
2010-01-19 by Lee Studley
Unfortunately, in California breathing air is considered a carcinogen. > 30~35% (wt) HCl is readily available as brick cleaner/ pool acidfier > here in Australia. Even sold in 250ml bottles up to 20L drum at some > local hardware stores. Its possible to remove some of the water, but not > practical. Normally, dry HCl is produced in an oven and then dissolved > in water until saturation, of which you get about 35% acid at STP. > > Adam __________ Information from ESET Smart Security, version of virus signature database 4786 (20100119) __________ The message was checked by ESET Smart Security. http://www.eset.com
2010-01-19 by Stefan Trethan
I'm absolutely positive there's HCl to be bought in California somewhere. It's just a matter of finding the source. ST
On Tue, Jan 19, 2010 at 5:52 PM, Lee Studley <indigo_red@...> wrote: > > Unfortunately, in California breathing air is considered a carcinogen. > >> 30~35% (wt) HCl is readily available as brick cleaner/ pool acidfier >> here in Australia. Even sold in 250ml bottles up to 20L drum at some >> local hardware stores. Its possible to remove some of the water, but not >> practical. Normally, dry HCl is produced in an oven and then dissolved >> in water until saturation, of which you get about 35% acid at STP. >> >> Adam > > >
2010-01-19 by halamander
You can purchase Muriatic Acid at any place that sells pool supplies. It is aqueous HCl. I don't know what concentration it comes in, but it's reasonably concentrated. --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan <stefan_trethan@...> wrote:
> > I'm absolutely positive there's HCl to be bought in California > somewhere. It's just a matter of finding the source. > > ST > > On Tue, Jan 19, 2010 at 5:52 PM, Lee Studley <indigo_red@...> wrote: > > > > Unfortunately, in California breathing air is considered a carcinogen. > > > >> 30~35% (wt) HCl is readily available as brick cleaner/ pool acidfier > >> here in Australia. Even sold in 250ml bottles up to 20L drum at some > >> local hardware stores. Its possible to remove some of the water, but not > >> practical. Normally, dry HCl is produced in an oven and then dissolved > >> in water until saturation, of which you get about 35% acid at STP. > >> > >> Adam > > > > > > >
2010-01-19 by Roger Blair
Stefan, Yes, there is. Finally after half a dozen different places that only sell 10% HCl, or muriatic acid "replacement", today I finally found a bona fide single purpose pool supply establishment that still carried 2 gallon packs of 32% (Muriatic Acid) HCl for $11, same price as the 10% stuff. Several Chemical supply outlets I tried would not sell hazmat to individuals, or wanted $25 or more for hazmat shipping charges on top of up to $138 for 37% stuff. I'm going to try the 32% HCl. Thanks everyone for the help, Roger
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Stefan Trethan Sent: Tuesday, January 19, 2010 10:29 AM To: Homebrew_PCBs@yahoogroups.com Subject: Re: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40% I'm absolutely positive there's HCl to be bought in California somewhere. It's just a matter of finding the source. ST On Tue, Jan 19, 2010 at 5:52 PM, Lee Studley <indigo_red@... <mailto:indigo_red%40qwest.net> > wrote: > > Unfortunately, in California breathing air is considered a carcinogen. > >> 30~35% (wt) HCl is readily available as brick cleaner/ pool acidfier >> here in Australia. Even sold in 250ml bottles up to 20L drum at some >> local hardware stores. Its possible to remove some of the water, but not >> practical. Normally, dry HCl is produced in an oven and then dissolved >> in water until saturation, of which you get about 35% acid at STP. >> >> Adam > > > [Non-text portions of this message have been removed]
2010-01-20 by Roger Blair
Bruce, The decimal point was where I wanted it to be, I simply approximated Which is only two or three points above the high end industrial/commercial production level for common usage at more or less ambient pressures and temperatures, according to what I have since learned. I have read there are apparently some rather esoteric processes that use above 40%. I didnt take the time to look into that, its far over my head, and not to the point. My point was only how to reduce the solution, which I quickly learned was not feasible. What I was after, was reducing my 10% concentration to roughly a 37-38% concentration, as has been recommended by many here for building a metal etchant, without spending a lot on chemical house pricing and special shipping. I finally found some 32% (referred to as Muriatic Acid) that I am now using to develop an etching process for tin/copper alloy. Thanks, Roger
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of ikc46118 Sent: Tuesday, January 19, 2010 6:49 AM To: Homebrew_PCBs@yahoogroups.com Subject: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40% 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 <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]
2010-01-20 by Adam Seychell
Roger Blair wrote: > > > Stefan, > > Yes, there is. Finally after half a dozen different places that only > sell 10% HCl, or muriatic acid "replacement" , today I finally > found a bona fide single purpose pool supply establishment that still > carried 2 gallon packs of 32% (Muriatic Acid) HCl for $11, > same price as the 10% stuff. Several Chemical supply outlets I tried > would not sell hazmat to individuals, or wanted $25 or more for > hazmat shipping charges on top of up to $138 for 37% stuff. I'm going to > try the 32% HCl. > > Thanks everyone for the help, > > Roger Just a note, 32%(wt) HCl is still "concentrated". You'll be hard pressed finding %40 HCl because vapour pressure is so high that the HCl gas will quickly escape, then slowing down as concentration drops to more a stable %35~%30 (wt). Also note your post subject line is contradictory.
2010-01-20 by Roger Blair
Yeah, my brain was saying reduce the solution (by evaporating off the water) to reach a 40% HCl concentration. I did say I know next to nothing about chemistry! BTW, isn't 40%, 37%, 32%, or 10% all levels of 'concentration'? There must be something else I'm not understanding. Thanks, Roger
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Adam Seychell Sent: Tuesday, January 19, 2010 6:03 PM To: Homebrew_PCBs@yahoogroups.com Subject: Re: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40% Roger Blair wrote: > > > Stefan, > > Yes, there is. Finally after half a dozen different places that only > sell 10% HCl, or muriatic acid "replacement" , today I finally > found a bona fide single purpose pool supply establishment that still > carried 2 gallon packs of 32% (Muriatic Acid) HCl for $11, > same price as the 10% stuff. Several Chemical supply outlets I tried > would not sell hazmat to individuals, or wanted $25 or more for > hazmat shipping charges on top of up to $138 for 37% stuff. I'm going to > try the 32% HCl. > > Thanks everyone for the help, > > Roger Just a note, 32%(wt) HCl is still "concentrated". You'll be hard pressed finding %40 HCl because vapour pressure is so high that the HCl gas will quickly escape, then slowing down as concentration drops to more a stable %35~%30 (wt). Also note your post subject line is contradictory. [Non-text portions of this message have been removed]
2010-01-20 by KeepIt SimpleStupid
Maybe this might help: http://www.qvf.com/en/processsystems_3/Mineral%20Acids/AbsorptionofHydrogenChloride.shtml It does show the max concentration at ~atmospheric pressure, 1 bar, to be somewhere between 40-45%. 42% looks right. --- On Tue, 1/19/10, Roger Blair <Roger.Blair@...> wrote:
From: Roger Blair <Roger.Blair@...>
Subject: RE: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40%
To: Homebrew_PCBs@yahoogroups.com
Date: Tuesday, January 19, 2010, 9:38 PM
Yeah, my brain was saying reduce the solution (by evaporating off the water) to reach a 40% HCl concentration. I did say I know next
to nothing about chemistry! BTW, isn't 40%, 37%, 32%, or 10% all levels of 'concentration' ? There must be something else I'm not
understanding.
Thanks,
Roger
From: Homebrew_PCBs@ yahoogroups. com [mailto:Homebrew_PCBs@ yahoogroups. com] On Behalf Of Adam Seychell
Sent: Tuesday, January 19, 2010 6:03 PM
To: Homebrew_PCBs@ yahoogroups. com
Subject: Re: [Homebrew_PCBs] Re: Reducing concentration of HCl from 10% to 40%
Roger Blair wrote:
>
>
> Stefan,
>
> Yes, there is. Finally after half a dozen different places that only
> sell 10% HCl, or muriatic acid "replacement" , today I finally
> found a bona fide single purpose pool supply establishment that still
> carried 2 gallon packs of 32% (Muriatic Acid) HCl for $11,
> same price as the 10% stuff. Several Chemical supply outlets I tried
> would not sell hazmat to individuals, or wanted $25 or more for
> hazmat shipping charges on top of up to $138 for 37% stuff. I'm going to
> try the 32% HCl.
>
> Thanks everyone for the help,
>
> Roger
Just a note, 32%(wt) HCl is still "concentrated" . You'll be hard pressed
finding %40 HCl because vapour pressure is so high that the HCl gas will
quickly escape, then slowing down as concentration drops to more a
stable %35~%30 (wt).
Also note your post subject line is contradictory.
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]2010-01-20 by Stefan Trethan
I think "concentrated" can be used to mean both, diluted (usually along with a % specification) as well as highest percentage possible. Language is a strange thing, when the words concentrated and diluted can mean the same thing. ;-) ST
On Wed, Jan 20, 2010 at 3:38 AM, Roger Blair <Roger.Blair@...> wrote: > BTW, isn't 40%, 37%, 32%, or 10% all levels of 'concentration'? There must be something else I'm not > understanding. >