Etching Questions

Discussion in 'General Electronics Chat' started by Dr.killjoy, Aug 19, 2015.

  1. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
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    I have a couple questions and was hoping someone had some input here.. I saw a video on youtube where a little girl was etching pcb with overhead transparency film and wanted to know if anyone has every tried it and does it really work and make it easier ?? Also I am trying to etch pcb in my apartment and I have little children running around and I was looking to use some what safe etch chemicals . So I was interested in using White Vinger with hydrogen Peroxide instead of the normal ferric chloride or muratic acid and Peroxide .. Has anyone tried it before and how has it come out ??





    Thanks
    Jay Sr
     
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  2. dl324

    Distinguished Member

    Mar 30, 2015
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    She wasn't etching with a transparency, but I know what you mean...

    I've tried half a dozen or so different types of transparencies and have found that not all will work. I've found that inkjet transparencies (yes, printed in a laser printer) released the best. No laser transparencies I tried wanted to release completely from the transparency.

    No etching chemical will be child safe. I use ferric chloride which I heat in a hot water bath to reduce etching times. I took to etching outside on my deck so I didn't have to worry about noxious fumes.

    I personally wouldn't rinse the boards in the sink; even if I wasn't on a septic system. Ferric chloride will stain and etch many things, including your skin. I use a small amount of water for rinsing and I save it and dispose with the used etchant.

    I wouldn't etch a circuit board the way the girl did. It may remove traces or cause them to be severely undercut. Agitating the etching container works for me...

    I get what I consider to be very good results. Far better than I ever did with paper. I plan to try wax paper transfer if I run out of inkjet transparencies. But once I found something that worked, I bought the transparencies in bulk and probably have a supply to last several lifetimes.
     
  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    A little research by you on the etching process would help... This subject has been discussed here so may times, it is becoming ...

    First, the only hazardous substance produced in etching copper PCB's using ferric chloride is oxidized copper .

    Is iron toxic? Yes, one can suffer iron toxicity from an overdose. But, you can also buy iron gluconate or sulfate over the counter as an iron supplement. How much soluble iron do you make etching a single PCB? Do the math. Second, one of the major uses of ferric chloride, if not the major use, is in sewage treatment. Look it up. How can that by itself hurt the sewage system? It is also used a root killer to clear blocked sewage systems.

    Can you drink ferric chloride? Well, that depends on how much you drink. If you drink a toxic amount, that is not good. Don't let your children or wife do that . Presumably, you won't either.

    Is a peroxide-HCl mixture for etching safer? No. And if you think so, please show us the data.

    While it is true that you can drink small amounts of white vinegar relatively safety -- I prefer red on my salad , I do not suggest that you drink hydrogen peroxide. Moreover, after mixing the former with the latter and etching a PCB, you have soluble copper salts -- virtually the same salts you get by using ferric chloride. I do not recommend drinking copper chloride or copper acetate salts, regardless of how they are produced.

    John
     
  4. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
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    Sorry I wasn't looking to bring up a old thread or start a large post about etching but just some input and answer from people I respect and appreciate their input ..
     
    Last edited: Aug 19, 2015
  5. dl324

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    I don't think you need to apologize. No one is forced to read or respond to a topic that doesn't interest them.
     
  6. Lestraveled

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    May 19, 2014
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    There are two very robust threads in the "Completed projects" section on making and etching PCBs, one using the laser printer method and one using the photographic method. Take a look, there is a lot of info in them.
     
  7. Lestraveled

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    There are two etchants that are nicer than ferric chloride; sodium persulfate or ammonium persulfate. They are clear when mixed with water, and will not stain if washed out soon enough. (Ferric chloride will stain anything instantly.)
     
  8. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
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    I have read both thread and can only do the thermal transfer and I was only asking about using the clear plastic sheets the girl used to transfer the toner instead of using mag paper and having to rub the paper off left over ...

    Oh ok cool will have to check them out see what happens ..
    Thanks Alot
    Jay Sr
     
  9. RichardO

    Well-Known Member

    May 4, 2013
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    I have used both ferric chloride and ammonium persulfate. The ferric chloride is cheap and etches quickly but is almost opaque making it had to see the progress of the etching. The ammonium persulfate is much more expensive (and etches slower than ferric chloride) but has the advantage it that it starts out nearly transparent and by the time it gets opaque it is no longer etching at a tolerable rate.
     
  10. Robin Mitchell

    Well-Known Member

    Oct 25, 2009
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    Im not sure why they say that ferric chloride is a corrosive chemical to biological matter. I have had my hand submerged in a ferric chloride tank as well as getting it on my skin very frequently. I find hydrogen peroxide, sodium hydroxide and sodium carbonate much worse. My hand will go red if any stripping chemicals make contact. Dont take my word for it but I find ferric chloride the least of my worries!
     
  11. Wendy

    Moderator

    Mar 24, 2008
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    How long did your hand stay brown? It does stain, rather well. And what it and similar etchants have done to my tools just by being near them (sad face).

    Any chemicals I would wear nitrile gloves.
     
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  12. dl324

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    This is from a MSDS for ferric chloride:

    Potential Acute Health Effects: Very hazardous in case of ingestion. Hazardous in case of skin contact (irritant), of eye contact (irritant), of inhalation. Slightly hazardous in case of skin contact (permeator). Corrosive to eyes and skin. The amount of tissue damage depends on length of contact. Eye contact can result in corneal damage or blindness. Skin contact can produce inflammation and blistering. Inhalation of dust will produce irritation to gastro-intestinal or respiratory tract, characterized by burning, sneezing and coughing. Severe over-exposure can produce lung damage, choking, unconsciousness or death.

    Potential Chronic Health Effects: CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance is toxic to lungs, mucous membranes. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated exposure of the eyes to a low level of dust can produce eye irritation. Repeated skin exposure can produce local skin destruction, or dermatitis. Repeated inhalation of dust can produce varying degree of respiratory irritation or lung damage.

    I've used ferric chloride to etch PCBs since the 70's. I detect a chlorine-like odor while etching, so I avoid breathing the fumes. I used to etch over the stove and use the hood to evacuate fumes; now I etch outside.
     
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  13. DerStrom8

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    Feb 20, 2011
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    There are articles out there describing PCB etching using hydrogen peroxide, vinegar, and salt. The chemicals that go into the mixture aren't particularly dangerous, but the byproducts after the etch probably shouldn't be dumped down the drain, and are not good for the environment.

    EDIT: Here's a link: http://quinndunki.com/blondihacks/?p=351
     
  14. dl324

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    IIRC, in sufficient quantity copper is toxic to most animals. People dump a lot of stuff down drains that they shouldn't. I have a septic system so I'm more sensitive to what I put down the drain. I could literally end up drinking it because my drain field is 100 feet from both of the wells on my property...
     
  15. Robin Mitchell

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    Oct 25, 2009
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    Well it will stain anything it touches but I can wipe it off my hands really easy. As for fumes my tanks have tight seals when the lid is closed and the only bad thing I can make out it the chlorine
     
  16. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    How then, is it best to dispose of ferric chloride? How can it be neutralized before dumping?
     
  17. dl324

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    I take to a hazardous waste site.

    I asked a friend who has a PhD in chemistry how to extract copper from the solution; he said it wouldn't be cost effective.
     
  18. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
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    How much does that cost you ??
     
  19. dl324

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    There's an annual hazardous waste collection day in my area. Free drop off; with limits on chemicals and quantity.
     
  20. Lestraveled

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