I just purchased 1lb. of anhydrous ferrous chloride. I need someone to check my numbers so I don't end up botching the whole mixing process.
The etching solution ratshack sells is about 40% FeCL by weight and 1-3% HCI.
So 1lb. = 454 grams and 1 liter of water weighs 1kg. That would mean I need just a tad bit more than 1 liter of water correct?
That doesn't seem like a lot of solution to me. I didn't do the math before hand and was hoping 1lb would make a little bit more than 1 liter. For what I paid for the anhydrous powder I could have just bought 4 16oz. bottles of pre-mixed. Oh well, live and learn.
The etching solution ratshack sells is about 40% FeCL by weight and 1-3% HCI.
So 1lb. = 454 grams and 1 liter of water weighs 1kg. That would mean I need just a tad bit more than 1 liter of water correct?
That doesn't seem like a lot of solution to me. I didn't do the math before hand and was hoping 1lb would make a little bit more than 1 liter. For what I paid for the anhydrous powder I could have just bought 4 16oz. bottles of pre-mixed. Oh well, live and learn.
A good liter of ferrous chloride solution lasts a while. The trick is not to dump it, but fill it in a plastic bottle and store it safe and cool (and check it for pressure buildup from time to time).
Before you reuse it, wait until any copper mud from etched boards has settled on the ground of the bottle (usually takes a day or two). Then gently pour the solution back into your etching container without spilling the copper mud with it.
The solution will exhaust only after a considerable number of boards (and re-uses). The liquid can be neutralized with anything basic (i.e. caustic soda from photoresist laquer developing) and disposed off, just don't spill it around, it will stain your kitchen basin or drain forever.
The copper mud is hazardous waste and has to be handled and disposed appropriately.
Cheers.
Before you reuse it, wait until any copper mud from etched boards has settled on the ground of the bottle (usually takes a day or two). Then gently pour the solution back into your etching container without spilling the copper mud with it.
The solution will exhaust only after a considerable number of boards (and re-uses). The liquid can be neutralized with anything basic (i.e. caustic soda from photoresist laquer developing) and disposed off, just don't spill it around, it will stain your kitchen basin or drain forever.
The copper mud is hazardous waste and has to be handled and disposed appropriately.
Cheers.
Thanks guys,
I just finished making the mix...... and a mess. I'm definitely buying pre-mixed next time. I threw about half a cup of "The Works" toilette bowl cleaner in the mix. It's the only way for me to get HCI without going out of my way. It contains 20% HCI by volume.
Time to see if this stuff will etch.
I just finished making the mix...... and a mess. I'm definitely buying pre-mixed next time. I threw about half a cup of "The Works" toilette bowl cleaner in the mix. It's the only way for me to get HCI without going out of my way. It contains 20% HCI by volume.
Time to see if this stuff will etch.
Not bleach.
HCI = hydrochloric acid
NaClO = Sodium hypochlorite (bleach)
The stuff from radioshack has HCI so I just copied their formula. I think it has something to do with the FeCL dissolving better and something about copper precipitates. I dunno. My mix turned out good though, I just etched a board in about 5 minutes.
HCI = hydrochloric acid
NaClO = Sodium hypochlorite (bleach)
The stuff from radioshack has HCI so I just copied their formula. I think it has something to do with the FeCL dissolving better and something about copper precipitates. I dunno. My mix turned out good though, I just etched a board in about 5 minutes.
You do not need hydrochloric acid to etch boards. In this case, the ferrous chloride is sufficient.
The stuff you get from Radio Shack, as near as I can tell, is nearly spent solution from production shops. It has just enough umph remaining to do a couple of small boards.
Back when I used Radio Shack solution to etch boards, they did not list hydrochloric acid. If they're adding it now, it's likely because they're using even more depleted solution than in the past and they're trying to beef it up.
If you're mixing a straight, fresh solution of ferrous chloride, I think you'll find that it's vastly more powerful than the Radio Shack solution.
Throwing "The Works" into a solution just because it's on hand is asking for trouble. You might as well throw gunpowder in while you're at it. This is one of those "if you don't know what you're doing, don't do it" sorts of things. You could easily set up a reaction that would evolve chlorine gas.
Is your Will up to date?
Grey
The stuff you get from Radio Shack, as near as I can tell, is nearly spent solution from production shops. It has just enough umph remaining to do a couple of small boards.
Back when I used Radio Shack solution to etch boards, they did not list hydrochloric acid. If they're adding it now, it's likely because they're using even more depleted solution than in the past and they're trying to beef it up.
If you're mixing a straight, fresh solution of ferrous chloride, I think you'll find that it's vastly more powerful than the Radio Shack solution.
Throwing "The Works" into a solution just because it's on hand is asking for trouble. You might as well throw gunpowder in while you're at it. This is one of those "if you don't know what you're doing, don't do it" sorts of things. You could easily set up a reaction that would evolve chlorine gas.
Is your Will up to date?
Grey
I appreaciate your concern Grey, but all is OK in Anonyville. No chlorine gas clouds here.
I found the article that explained the use of HCI when using anhydrous FeCL.
Quote was taken from here http://www.electricstuff.co.uk/pcbs.html.
I found the article that explained the use of HCI when using anhydrous FeCL.
Quote was taken from here http://www.electricstuff.co.uk/pcbs.html.
Oh my,
I used to be like you. Really.
I also wanted do improve upon things I hadn't even started. Wanted to make everything perfectly optimal right from the start.
I'm okay, I'm over it when it comes to board etching!
No, really, there are so many things while printing, etching, drilling, stuffing, soldering and testing boards, which might go 'suboptimal' when you do it for the first couple of times, that you shouldn't worry too much about the very first step. Just use the ferric chloride you buy like the manufacturer advises. It will work. It might work better and more professional in other ways, but not really using ferric chloride, so why bother.
Cheers.
I used to be like you. Really.
I also wanted do improve upon things I hadn't even started. Wanted to make everything perfectly optimal right from the start.
I'm okay, I'm over it when it comes to board etching!
No, really, there are so many things while printing, etching, drilling, stuffing, soldering and testing boards, which might go 'suboptimal' when you do it for the first couple of times, that you shouldn't worry too much about the very first step. Just use the ferric chloride you buy like the manufacturer advises. It will work. It might work better and more professional in other ways, but not really using ferric chloride, so why bother.
Cheers.
I wasn't really trying to improve anything; I just wanted it to work. I purchased anhydrous FeCL instead of hexahydrate. I read in more than one place that the anhydrous form was not preferred, so I was a bit worried and just followed someone else's advice about adding the HCI. I guess I could have tested the mix before I added the HCI, but I didn't see a reason at the time to not add it.
Everything turned out OK, maybe with a bit of luck. I realize I probably should have thought a little more before I acted. Maybe next time.
Everything turned out OK, maybe with a bit of luck. I realize I probably should have thought a little more before I acted. Maybe next time.
An externally hosted image should be here but it was not working when we last tested it.
I hate the characteristics of the Radio Shack solution so much I just can't use it anymore.
For starters...
1) it stains
2) it's weak
3) It requires added heat
4) it's opaque
I now only use the gootee method: http://www.fullnet.com/~tomg/gooteepc.htm
Snippet from the page...
It's made by adding 1 part Muriatic Acid (the common kind that's sold in hardware stores, which is actually 28% Hydrochloric Acid) to 2 parts Hydrogen Peroxide (the common 3% kind that's sold in drugstores and pharmacies). This etchant can etch a 1-oz board in about five minutes, at room temperature, with gentle mechanical agitation. And it's almost transparent.
Cheap, easy, readily available. (IMHO only slightly more dangerous) Can't beat that.
For starters...
1) it stains
2) it's weak
3) It requires added heat
4) it's opaque
I now only use the gootee method: http://www.fullnet.com/~tomg/gooteepc.htm
Snippet from the page...
It's made by adding 1 part Muriatic Acid (the common kind that's sold in hardware stores, which is actually 28% Hydrochloric Acid) to 2 parts Hydrogen Peroxide (the common 3% kind that's sold in drugstores and pharmacies). This etchant can etch a 1-oz board in about five minutes, at room temperature, with gentle mechanical agitation. And it's almost transparent.
Cheap, easy, readily available. (IMHO only slightly more dangerous) Can't beat that.
I neutralize the Muriatic Acid (HCL)/ Hydrogen Peroxide mixture with Baking Soda.
Since Aqueous Ferric Chloride from Radio Shack is usually created as the waste product of metal "pickling" (essentially HCL reacted with rust), you might have luck using baking soda as well... but I'm not a chemist.
Since Aqueous Ferric Chloride from Radio Shack is usually created as the waste product of metal "pickling" (essentially HCL reacted with rust), you might have luck using baking soda as well... but I'm not a chemist.
ferric chloride disposal
I am a chemist... dump it down the toilet with a few good flushes... or you can neutralize with bicarb or powdered limestone for that matter... but you'll end up with a sludge of goo...
As long as you dispose of less than maybe 1 quart spent soln at a time.. use the toilet with several flushes....
I also much prefer the HCl/H202 soln...
John L.
I am a chemist... dump it down the toilet with a few good flushes... or you can neutralize with bicarb or powdered limestone for that matter... but you'll end up with a sludge of goo...
As long as you dispose of less than maybe 1 quart spent soln at a time.. use the toilet with several flushes....
I also much prefer the HCl/H202 soln...
John L.
Ferrous Chloride (FeCl2) will not work!
You need to buy Ferric Chloride (FeCl3) for PCB etching.
Unfortunately, Ferrous Chloride is the byproduct from the
reaction of metallic copper and FeCl3. Sorry to be the bearer
of bad news.
Ferric Chloride powder is corrosive, so be careful about getting
the powder or dust on anything. You can buy clear, aqueous
HCl from a pool supply or even Home Depot - which sells Muriatic
Acid by the gallon for brick and concrete cleaning. Avoid HCl products that contain any additional detergents, phosphates, etc.
You want hydrogen chloride and water. Nothing else. Read the label.
You can pour FeCl3 down the toilet... If you want, you can neutralize it first with sodium hydroxide. Three tablespoons
of Draino very slowly dissolved in cold water.. Goggles are
mandatory here as NaOH solution can get hot and if it gets in
the eyes it will severely damage them. Next, trickle the NaOH
solution slowly into the ferric chloride waste... You'll get a brown
sludge.... This brown sludge is simply rust.... Well, a hydrated
form of rust. Rust is environmentally friendly. Consider any excess sodium hydroxide that you flush down the drain to be your own tiny part on the war on acid rain.
-- Jim
You need to buy Ferric Chloride (FeCl3) for PCB etching.
Unfortunately, Ferrous Chloride is the byproduct from the
reaction of metallic copper and FeCl3. Sorry to be the bearer
of bad news.
Ferric Chloride powder is corrosive, so be careful about getting
the powder or dust on anything. You can buy clear, aqueous
HCl from a pool supply or even Home Depot - which sells Muriatic
Acid by the gallon for brick and concrete cleaning. Avoid HCl products that contain any additional detergents, phosphates, etc.
You want hydrogen chloride and water. Nothing else. Read the label.
You can pour FeCl3 down the toilet... If you want, you can neutralize it first with sodium hydroxide. Three tablespoons
of Draino very slowly dissolved in cold water.. Goggles are
mandatory here as NaOH solution can get hot and if it gets in
the eyes it will severely damage them. Next, trickle the NaOH
solution slowly into the ferric chloride waste... You'll get a brown
sludge.... This brown sludge is simply rust.... Well, a hydrated
form of rust. Rust is environmentally friendly. Consider any excess sodium hydroxide that you flush down the drain to be your own tiny part on the war on acid rain.
-- Jim
This is again where it shows how far our continents are apart. 
In an ideal world, the waste - neutralized and uncorrosive - would flush down all the pipes and tubes, not staining anything, not falling out on it's way to the water recycling facility - which you were all connected to, as it would be an ideal world.
In my case, none of this works. I don't know about you!
I of course know that nobody will be directly affected by waste etching solution in the drain, but it's a matter of attitude, of awareness, of environmental thinking.
I'd say in reality the bowl will stain (over time), the pipes and the local drains waterways will collect the copper sludge ... and the 'rust' (poisonous heavy metal salt), as it's jokingly called, will poison the bacteria and microbes in the water recycling plant - in case you are connected to one (and if not, who cares, right?...).
Do you flush laquer down the drain? Turpentine? Oil? Benzine? Hmmm, if you don't - why not? If you do - hit your head hard!
I already recommended to neutralize the solution after exhausting it, split the liquids from the solid sludge, flush away the liquids and dispose the sludge off properly, at a recycling or collecting facility. And I stand to it. It's also what manufacturers of etching chemicals recommend, by the way.
Just collect the etching sludge as you collect laquer or old oil. And next time you go dispose off the laquer or oil appropriately, just take the copper sludge with you.
Anybody who works as a chemist should know this, and probably just forgot that a lab usually has special drains maintenance...
Cheers,
Sebastian.
In an ideal world, the waste - neutralized and uncorrosive - would flush down all the pipes and tubes, not staining anything, not falling out on it's way to the water recycling facility - which you were all connected to, as it would be an ideal world.
In my case, none of this works. I don't know about you!
I of course know that nobody will be directly affected by waste etching solution in the drain, but it's a matter of attitude, of awareness, of environmental thinking.
I'd say in reality the bowl will stain (over time), the pipes and the local drains waterways will collect the copper sludge ... and the 'rust' (poisonous heavy metal salt), as it's jokingly called, will poison the bacteria and microbes in the water recycling plant - in case you are connected to one (and if not, who cares, right?...).
Do you flush laquer down the drain? Turpentine? Oil? Benzine? Hmmm, if you don't - why not? If you do - hit your head hard!
I already recommended to neutralize the solution after exhausting it, split the liquids from the solid sludge, flush away the liquids and dispose the sludge off properly, at a recycling or collecting facility. And I stand to it. It's also what manufacturers of etching chemicals recommend, by the way.
Just collect the etching sludge as you collect laquer or old oil. And next time you go dispose off the laquer or oil appropriately, just take the copper sludge with you.
Anybody who works as a chemist should know this, and probably just forgot that a lab usually has special drains maintenance...
Cheers,
Sebastian.
Wrong....
I s'pose it's a matter of degree...
Iron sludge is not heavy metal waste....
As far as the copper content, well, if you use public water supplies, there's more copper there than you'd ever contaminate dumping "hobby waste"..
get a life... do you drive a car... walk in the streets...use electricity... burn gasoline... heat your house... eat processed food...
I'm a chemist, and now run a pediatric medical office.. worked for the EPA for years.. been in the plating industry for decades ...have probably forgotten more about waste disposal and pollution than you ever knew...
so don't patronize and preach to the experts about "special drains maintenance"..
gimme a break
John L.
sek said:This is again where it shows how far our continents are apart.
In an ideal world, the waste - neutralized and uncorrosive - would flush down all the pipes and tubes, not staining anything, not falling out on it's way to the water recycling facility - which you were all connected to, as it would be an ideal world.
In my case, none of this works. I don't know about you!
I of course know that nobody will be directly affected by waste etching solution in the drain, but it's a matter of attitude, of awareness, of environmental thinking.
I'd say in reality the bowl will stain (over time), the pipes and the local drains waterways will collect the copper sludge ... and the 'rust' (poisonous heavy metal salt), as it's jokingly called, will poison the bacteria and microbes in the water recycling plant - in case you are connected to one (and if not, who cares, right?...).
Do you flush laquer down the drain? Turpentine? Oil? Benzine? Hmmm, if you don't - why not? If you do - hit your head hard!
I already recommended to neutralize the solution after exhausting it, split the liquids from the solid sludge, flush away the liquids and dispose the sludge off properly, at a recycling or collecting facility. And I stand to it. It's also what manufacturers of etching chemicals recommend, by the way.
Just collect the etching sludge as you collect laquer or old oil. And next time you go dispose off the laquer or oil appropriately, just take the copper sludge with you.
Anybody who works as a chemist should know this, and probably just forgot that a lab usually has special drains maintenance...
Cheers,
Sebastian.
I s'pose it's a matter of degree...
Iron sludge is not heavy metal waste....
As far as the copper content, well, if you use public water supplies, there's more copper there than you'd ever contaminate dumping "hobby waste"..
get a life... do you drive a car... walk in the streets...use electricity... burn gasoline... heat your house... eat processed food...
I'm a chemist, and now run a pediatric medical office.. worked for the EPA for years.. been in the plating industry for decades ...have probably forgotten more about waste disposal and pollution than you ever knew...
so don't patronize and preach to the experts about "special drains maintenance"..
gimme a break
John L.
Hi,
whatever you do in private is your problem.
Our local university had wastewater problems with the city and therefore the galvanic solutions were collected for proper disposal or at least the copper is dropped out of solutions using NaOH.
The sludge, containing iron and copper, settles down and is collected. Only the remaining solution is flushed away.
Regards
Jürgen
whatever you do in private is your problem.
Our local university had wastewater problems with the city and therefore the galvanic solutions were collected for proper disposal or at least the copper is dropped out of solutions using NaOH.
The sludge, containing iron and copper, settles down and is collected. Only the remaining solution is flushed away.
Regards
Jürgen
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.