Author Topic: Want to start making my own circuit board where to start  (Read 23585 times)

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Offline janoc

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Re: Want to start making my own circuit board where to start
« Reply #125 on: August 29, 2017, 10:17:51 pm »
What is the point of neutralizing the ph of HCl when it is diluted 1000 times?

And do you really want (or have means) to dilute it 1000x? That's quite a bit of water to mix in if you are using concentrated acid!

Apart from precipitating the copper out of the solution there is also another reason for neutralization - it converts the compounds into something that is potentially less harmful when disposing of it.

E.g. neutralizing hydrochloric acid with baking soda will produce a saline solution and carbon dioxide - both harmless substances that you can safely pour even down the drain, whereas doing that with even diluted acid is not a good idea (could slowly attack the piping, messes up the bacteria in the sewage treatment stations, etc.).

Even if you are drying the solution out to dispose of it it is probably safer to have water evaporate than the acid - HCl fumes are no fun. So neutralizing it beforehand will help with that - it will fizz with carbon dioxide while the reaction is going but that's all. Then all you will be left with will be some salts that will crystallize out as the water evaporates and no aggressive fumes.

« Last Edit: August 29, 2017, 10:25:57 pm by janoc »
 

Offline janoc

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Re: Want to start making my own circuit board where to start
« Reply #126 on: August 29, 2017, 10:39:00 pm »
I remember adding baking soda, IIRC, to some ferric, once. More or less just to see what would happen. Instead of iron and copper compounds precipitating out, it just made an icky brown hygroscopic gelatin that could not be strained.

You need to dry it out, e.g. spill it on a tray covered with paper or filter it through a paper filter. Then let the water evaporate.

The brown "gelatin" you got is ferric oxide - basically rust. Copper will form a copper carbonate which has greenish color, however the ferric oxide will likely be more visible so it will be tricky to see unless there is a large amount of cupric chloride in the solution.

Another way to neutralize spent ferric/cupric chloride etchant would be to add aluminium shavings - that will precipitate metallic copper out of the solution. However, that could be more tricky to do - baking soda is easier to obtain than metals, plus powdered aluminium (not shavings) is a major fire hazard.
« Last Edit: August 29, 2017, 10:47:31 pm by janoc »
 

Offline sasa

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Re: Want to start making my own circuit board where to start
« Reply #127 on: August 30, 2017, 01:19:09 am »
Basic chemical reactions regarding Ferric/Cupric Chloride should be handy to know are following (not balanced):

Fe + O2 -> Fe2O3
Fe + Cl2 -> FeCl3
Fe + HCl -> FeCl2 + H2

FeCl2 + O2 -> Fe2O3 + FeCl3
FeCl2 + O2 + HCl -> FeCl3 + H2O

CuCl2 + Cu -> 2 CuCl
CuCl + HCl + O2 -> CuCl2 + H2O

FeCl3 + Cu -> FeCl2 + CuCl
FeCl3 + CuCl -> FeCl2 + CuCl2

CuCl2 + Fe -> FeCl2 + Cu

Neutralization:

HCl + NaHCO3  -> NaCl + H2O + CO2
CuCl2 + NaHCO3 -> CuCO3 + NaCl + H2O + CO2    (CuCO3 is insoluble in water)
FeCl2 + NaHCO3 -> FeCO3 + NaCl + H2O + CO2

Attention: I'm not a chemist, thus upper may not be exact. I have collected them long time ago from various sources. Please post corrections if notice some problems with.
« Last Edit: August 30, 2017, 01:51:07 am by sasa »
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Offline BeaminTopic starter

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Re: Want to start making my own circuit board where to start
« Reply #128 on: August 31, 2017, 11:54:32 am »
This thread derailed and crashed a long time ago.  If you want to debate safety start another thread on that subject.

Agreed. Whats ironic if I made a video of myself getting hurt with acid everyone in this thread would want to watch it. Then say "I told you so".
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Offline sasa

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Re: Want to start making my own circuit board where to start
« Reply #129 on: August 31, 2017, 03:25:04 pm »
Whats ironic if I made a video of myself getting hurt with acid everyone in this thread would want to watch it. Then say "I told you so".

Again, you making wrong assumptions... Who sane will love to watch how you (or anyone else) getting hurt with acid?

...
Am I missing something?

As already pointed:

1. Many actual beginners read this - for them it is the best advice not to play with HCl as primary etchant.  You did represent yourself as such...

2. Some people and most of kids are quite irresponsible and their primary goal is to make pranks with themselves or others, regardless they are aware of deadly risks or not. But most of them will think twice if deadly risks is involved.

As well, I doubt many people who use muriatic acid in domestic ever read and even understand fully what is wrote on the bottle...
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Offline janoc

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Re: Want to start making my own circuit board where to start
« Reply #130 on: August 31, 2017, 07:40:16 pm »
Again, you making wrong assumptions... Who sane will love to watch how you (or anyone else) getting hurt with acid?

The same people who post/watch videos on Youtube of people getting killed or maimed. Or crowds that ogle an accident, everyone with a phone in hand recording it, but nobody will help the people that are possibly dying there.

Don't underestimate human egoism, stupidity and fascination with someone else getting hurt ...
 

Offline sasa

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Re: Want to start making my own circuit board where to start
« Reply #131 on: September 01, 2017, 09:46:04 am »
Again, you making wrong assumptions... Who sane will love to watch how you (or anyone else) getting hurt with acid?

The same people who post/watch videos on Youtube of people getting killed or maimed. Or crowds that ogle an accident, everyone with a phone in hand recording it, but nobody will help the people that are possibly dying there.

And in this thread these are all? I do not think so...

Quote
Don't underestimate human egoism, stupidity and fascination with someone else getting hurt ...

Certainly I do not, as I commented already. All I wrote here is to prevent any inexperience and not well informed, especially absolute beginners in etching, to get hurt or kill himself or other, or do any other stupidity...

But honestly, I'm a bit disappointed Beamin did not wrote or at least commented chemical reactions I have posted. Instead, he wrote this...

« Last Edit: September 01, 2017, 10:07:07 am by sasa »
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Offline BeaminTopic starter

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Re: Want to start making my own circuit board where to start
« Reply #132 on: September 01, 2017, 10:59:59 pm »
Again, you making wrong assumptions... Who sane will love to watch how you (or anyone else) getting hurt with acid?

The same people who post/watch videos on Youtube of people getting killed or maimed. Or crowds that ogle an accident, everyone with a phone in hand recording it, but nobody will help the people that are possibly dying there.

And in this thread these are all? I do not think so...

Quote
Don't underestimate human egoism, stupidity and fascination with someone else getting hurt ...

Certainly I do not, as I commented already. All I wrote here is to prevent any inexperience and not well informed, especially absolute beginners in etching, to get hurt or kill himself or other, or do any other stupidity...

But honestly, I'm a bit disappointed Beamin did not wrote or at least commented chemical reactions I have posted. Instead, he wrote this...

I tend to click on the last page of a thread and often miss things.

If you look up nile red's youtube channel you will see his "pouring acid on my hand video" as one of his most if not the most popular. 

I fell if someone asks a question and you know what you are talking about you should give them the most information you can. Its not the internets job to be a parent or baby sitter. I have read countless forums where someone gets something potentially dangerous like a laser or High voltage supply and people just write back: "I don't feel comfortable giving you that information" or "that's dangerous don't do it" with out explaining why its dangerous. Then the person who could be a stupid kid or a very responsible adult has no information to go off of and might make bad decisions. "But a young kid might be reading this forum!" Yes they might once again you are not responsible for them and if you really want to make sure they don't get hurt arm them with knowledge instead of lecturing or trying to talk them out of it which is going to up the forbidden fruit factor. The most fun I had when I was a kid was using the most dangerous things possible. I never got hurt or got my friends hurt. I was often the "Range safety officer". I was much smarter then my friends and I knew they were going to play with gun powder/chemicals and other things so instead of telling them NO! I would help them, explain how you could get hurt and if I didn't think they were smart enough to handle things I would do the most hazardous parts. In all the crazy stuff we did (for obvious reasons I won't elaborate because some things were illegal to posses or make) no one ever got hurt and no property was ever damaged (other then the things we were trying to destroy). I attribute this to my constantly reading the internet and learning about things. If I didn't have that resource I would have tried anyways and probably been badly hurt. I can think of more then one time when things could have gone terribly wrong but didn't because I had read where someone did it like "this" and ended up in the hospital, so we did it like "that" instead. For example I remember my friend would have accidentally got gun powder into some threads being screwed on and that would have ignited prematurely; killing them and all around us. Luckily someone had posted a story on the internet about that accident and I learned from it.
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Offline KL27x

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Re: Want to start making my own circuit board where to start
« Reply #133 on: September 01, 2017, 11:08:30 pm »
Quote
If you look up nile red's youtube channel you will see his "pouring acid on my hand video" as one of his most if not the most popular.
I have seen this. Yes, I have taken boards in/out of a horizontal etch tank without gloves, and it won't melt your skin off, lol. But repeated brief exposure will give you some painful hangnails! :) Is best to avoid direct contact as much as possible and immediately dilute/rinse after exposure. HCl will also burn holes right through a brand new cotton shirt in short order. :(

Skin is pretty tough stuff. I was only half joking when I mentioned spilling it on your crotch. The mucous membranes of eyes/nose/mouth, as well as the ones below your belly button, are the bits that are not going to like direct contact even for a second.

This thread prompted me to google hydrofluoric acid accidents. One of the more memorable ones was 2 guys filling a bucket by putting it on top of a stack of shipping crates so they could tip a 55 gallon drum of 70% HF acid into it. This is an example of what can happen trying to do something with the wrong equipment. The biggest accident I found was made by a couple of workers unloading a tanker truck of HF acid using compressed air, and skipping some safety procedures. A very unfortunate accident occurred partially because the chemist was extraordinarily tall. The hooded bench was too short for him, so he was sitting when he tipped over a small container of HF, which then spilled onto his thighs. The investigation also concluded that he would have had a better chance if he had more water available. The lab was equipped with a water hose, but the flow was rather low. 6L per minute, IIRC. If he had large bucket of water on hand, he might have lived.

Of course HCl is much less of a danger. But even if it means saving a perfectly fine pair of jeans, or preventing yourself from stubbing a toe or pulling a muscle while running for the shower and/or getting out of your clothes in record time, having some basic stuff on hand can help prevent some wishful hindsight. And if people are willing to take such chances with HF acid for something as mundane as their job, I imagine there are plenty of people willing to take some liberties in order to get their very first board etched.
« Last Edit: September 02, 2017, 12:07:58 am by KL27x »
 

Online tooki

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Re: Want to start making my own circuit board where to start
« Reply #134 on: September 02, 2017, 01:33:48 pm »
I tend to click on the last page of a thread and often miss things.
FYI, you should get in the habit of using the orange "NEW" buttons in the forum listings -- it takes you directly to the first unread post since your last visit to that thread.
 

Offline BeaminTopic starter

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Re: Want to start making my own circuit board where to start
« Reply #135 on: September 02, 2017, 11:27:10 pm »
Quote
If you look up nile red's youtube channel you will see his "pouring acid on my hand video" as one of his most if not the most popular.
I have seen this. Yes, I have taken boards in/out of a horizontal etch tank without gloves, and it won't melt your skin off, lol. But repeated brief exposure will give you some painful hangnails! :) Is best to avoid direct contact as much as possible and immediately dilute/rinse after exposure. HCl will also burn holes right through a brand new cotton shirt in short order. :(

Skin is pretty tough stuff. I was only half joking when I mentioned spilling it on your crotch. The mucous membranes of eyes/nose/mouth, as well as the ones below your belly button, are the bits that are not going to like direct contact even for a second.

This thread prompted me to google hydrofluoric acid accidents. One of the more memorable ones was 2 guys filling a bucket by putting it on top of a stack of shipping crates so they could tip a 55 gallon drum of 70% HF acid into it. This is an example of what can happen trying to do something with the wrong equipment. The biggest accident I found was made by a couple of workers unloading a tanker truck of HF acid using compressed air, and skipping some safety procedures. A very unfortunate accident occurred partially because the chemist was extraordinarily tall. The hooded bench was too short for him, so he was sitting when he tipped over a small container of HF, which then spilled onto his thighs. The investigation also concluded that he would have had a better chance if he had more water available. The lab was equipped with a water hose, but the flow was rather low. 6L per minute, IIRC. If he had large bucket of water on hand, he might have lived.

Of course HCl is much less of a danger. But even if it means saving a perfectly fine pair of jeans, or preventing yourself from stubbing a toe or pulling a muscle while running for the shower and/or getting out of your clothes in record time, having some basic stuff on hand can help prevent some wishful hindsight. And if people are willing to take such chances with HF acid for something as mundane as their job, I imagine there are plenty of people willing to take some liberties in order to get their very first board etched.

Cotton is cellulose. I have never been able to dissolve it in HCl. Scweitzers reagent which contains copper will dissolve it. sulfuric will dehydrate the cotton burning holes.
What makes HF dangerous is the fact fluorine reacts with calcium ions in your nerves. Its probably the most painful acid because it doesn't destroy the nerves. Its not as strong as HCl; you would think it would be stronger because fluorine is above Cl in the group and the trend goes up: HI then HBr then HCl but the valance electrons in F are too close to the nucleus. Also some acid don't fully dissociate ( turn the H into H+; hydronium) but some dissociate twice. Coke is bad for your teeth because phosphoric acid dissociates twice at two different pH's.   
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Offline KL27x

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Re: Want to start making my own circuit board where to start
« Reply #136 on: September 03, 2017, 01:40:23 am »
Quote
Cotton is cellulose. I have never been able to dissolve it in HCl. Scweitzers reagent which contains copper will dissolve it.
I stand corrected. Tag on (replacement) shirt is all synthetic, lol.
 


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