Removing battery corrosion

Started by February 11, 2018
I got an old AM-FM pocket transistor radio which looked good and clean
till I opened the battery compartment. Very corroded carbon zinc
batteries were in it. After removing them, I cleaned off as much of the
corrosion as possible by scraping with a plastic stick, and scrubbing
with q-tips and rubbing alcohol. That got rid of most of it, and I was
surprised to find the battery clips are not badly damaged, but I had to
use a fingernail file (sandpaper strip) on the ends of the springs. 

Better yet, the radio works perfectly.

But there is still a little of that battery corrosion still in there. In
all the years I've worked on electronics, I have never found a perfect
way to clean up leaked batteries. Is there some sort of spray or a
chemical that will dissolve or deactivate that crap? 

Of course it has to be safe for the circuit board and components too. I
use the 91% isopropyl alcohol, so it evaporates quickly and leaves
little water residue behind. (Then leave it dry well before use). 

On Sun, 11 Feb 2018 04:52:51 -0600, oldschool@tubes.com wrote:

>I got an old AM-FM pocket transistor radio which looked good and clean >till I opened the battery compartment. Very corroded carbon zinc >batteries were in it. After removing them, I cleaned off as much of the >corrosion as possible by scraping with a plastic stick, and scrubbing >with q-tips and rubbing alcohol. That got rid of most of it, and I was >surprised to find the battery clips are not badly damaged, but I had to >use a fingernail file (sandpaper strip) on the ends of the springs. > >Better yet, the radio works perfectly. > >But there is still a little of that battery corrosion still in there. In >all the years I've worked on electronics, I have never found a perfect >way to clean up leaked batteries. Is there some sort of spray or a >chemical that will dissolve or deactivate that crap? > >Of course it has to be safe for the circuit board and components too. I >use the 91% isopropyl alcohol, so it evaporates quickly and leaves >little water residue behind. (Then leave it dry well before use).
I like dish detergent and a soak in very hot water then scrub with a toothbrush and let dry in a warm oven, for hours. But with unsealed potentiometers, or those poly insulated tuning caps they used back in the day, I wouldn't recommend it. WD-40 seems to work well in electronics. Good for noisy pots and can help keep out moisture.
On Sunday, February 11, 2018 at 6:59:23 AM UTC-6, default wrote:
> On Sun, 11 Feb 2018 04:52:51 -0600, oldschool@tubes.com wrote: > > >I got an old AM-FM pocket transistor radio which looked good and clean > >till I opened the battery compartment. Very corroded carbon zinc > >batteries were in it. After removing them, I cleaned off as much of the > >corrosion as possible by scraping with a plastic stick, and scrubbing > >with q-tips and rubbing alcohol. That got rid of most of it, and I was > >surprised to find the battery clips are not badly damaged, but I had to > >use a fingernail file (sandpaper strip) on the ends of the springs. > > > >Better yet, the radio works perfectly. > > > >But there is still a little of that battery corrosion still in there. In > >all the years I've worked on electronics, I have never found a perfect > >way to clean up leaked batteries. Is there some sort of spray or a > >chemical that will dissolve or deactivate that crap? > > > >Of course it has to be safe for the circuit board and components too. I > >use the 91% isopropyl alcohol, so it evaporates quickly and leaves > >little water residue behind. (Then leave it dry well before use). > > I like dish detergent and a soak in very hot water then scrub with a > toothbrush and let dry in a warm oven, for hours. But with unsealed > potentiometers, or those poly insulated tuning caps they used back in > the day, I wouldn't recommend it. > > WD-40 seems to work well in electronics. Good for noisy pots and can > help keep out moisture.
I recommend swabbing with a solution of sodium bicarbonate to neutralize the acid.
On Sun, 11 Feb 2018 04:52:51 -0600, oldschool@tubes.com wrote:

>But there is still a little of that battery corrosion still in there. In >all the years I've worked on electronics, I have never found a perfect >way to clean up leaked batteries. Is there some sort of spray or a >chemical that will dissolve or deactivate that crap?
I use 409 spray cleaner, a plastic scraper, and a paint brush. For alkaline cells, scrape off as much of the white powder as possible. Clean what you can with the small paint brush. Then attack with the 409 spray. It will evaporate dry in about an hour. If you have an air compressor, you can blow out the excess liquid and it will dry quicker. It's been so long since I've seen any equipment that uses a carbon zinc cell, that I don't recall how it's cleaned. Probably some alkaline cleaner. The most common problem I see are corroded battery springs and contacts. Once the plating is gone, it's difficult to keep them from corroding again. Grease helps, but makes a mess. So, I replace them with similar or identical spring contacts purchased on eBay and other online vendors: <https://www.ebay.com/sch/i.html?_nkw=battery+spring+contact> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Since this layer is alcaline, the best to use an acid ; vinegar for 
instance.

oldschool@tubes.com a &eacute;crit&nbsp;:
> I got an old AM-FM pocket transistor radio which looked good and clean > till I opened the battery compartment. Very corroded carbon zinc > batteries were in it. After removing them, I cleaned off as much of the > corrosion as possible by scraping with a plastic stick, and scrubbing > with q-tips and rubbing alcohol. That got rid of most of it, and I was > surprised to find the battery clips are not badly damaged, but I had to > use a fingernail file (sandpaper strip) on the ends of the springs. > > Better yet, the radio works perfectly. > > But there is still a little of that battery corrosion still in there. In > all the years I've worked on electronics, I have never found a perfect > way to clean up leaked batteries. Is there some sort of spray or a > chemical that will dissolve or deactivate that crap? > > Of course it has to be safe for the circuit board and components too. I > use the 91% isopropyl alcohol, so it evaporates quickly and leaves > little water residue behind. (Then leave it dry well before use). >
On Sun, 11 Feb 2018 05:53:28 -0800 (PST), Andy
<andrewkennedy775@gmail.com> wrote:

>On Sunday, February 11, 2018 at 6:59:23 AM UTC-6, default wrote: >> On Sun, 11 Feb 2018 04:52:51 -0600, oldschool@tubes.com wrote: >> >> >I got an old AM-FM pocket transistor radio which looked good and clean >> >till I opened the battery compartment. Very corroded carbon zinc >> >batteries were in it. After removing them, I cleaned off as much of the >> >corrosion as possible by scraping with a plastic stick, and scrubbing >> >with q-tips and rubbing alcohol. That got rid of most of it, and I was >> >surprised to find the battery clips are not badly damaged, but I had to >> >use a fingernail file (sandpaper strip) on the ends of the springs. >> > >> >Better yet, the radio works perfectly. >> > >> >But there is still a little of that battery corrosion still in there. In >> >all the years I've worked on electronics, I have never found a perfect >> >way to clean up leaked batteries. Is there some sort of spray or a >> >chemical that will dissolve or deactivate that crap? >> > >> >Of course it has to be safe for the circuit board and components too. I >> >use the 91% isopropyl alcohol, so it evaporates quickly and leaves >> >little water residue behind. (Then leave it dry well before use). >> >> I like dish detergent and a soak in very hot water then scrub with a >> toothbrush and let dry in a warm oven, for hours. But with unsealed >> potentiometers, or those poly insulated tuning caps they used back in >> the day, I wouldn't recommend it. >> >> WD-40 seems to work well in electronics. Good for noisy pots and can >> help keep out moisture. > >I recommend swabbing with a solution of sodium bicarbonate to neutralize the acid.
What acid?
On Sun, 11 Feb 2018 20:35:56 +0100, Look165 <look165@numericable.fr>
wrote:

>Since this layer is alcaline, the best to use an acid ; vinegar for >instance.
<https://en.wikipedia.org/wiki/Alkaline_battery#Leaks> Yep. The white stuff from an alkaline cell is potassium carbonate and has a pH of about 11 in water: <https://en.wikipedia.org/wiki/Potassium_carbonate> Vinegar works, but citric acid (lemon juice) smells better. If the cleaner produces gas bubbles, it's working. However, I don't think it matters much. I use 409 household cleaner which has a pH of 9 to 11.5 depending on concentration: <http://www.gjfood.com/pdf/msds/79_820040.pdf> It produces some bubbles, does a good job of cleaning, and smells ok. The white stuff that leaks out of carbon zinc battery is the zinc chloride electrolyte: <https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery#Durability> <https://en.wikipedia.org/wiki/Zinc_chloride> Zinc chloride in water is very acidic with a pH of 2.0 to 3.0 depending on concentration. It's very soluble in water so any water based alkaline cleaner, such as houshold ammonia, should work. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Sun, 11 Feb 2018 14:35:43 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>The white stuff that leaks out of carbon zinc battery is the zinc >chloride electrolyte:
Oops. Zinc chloride is the crud that leaks out of the battery. The electrolyte is ammonium chloride. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On 11/02/18 23:38, Jeff Liebermann wrote:
> On Sun, 11 Feb 2018 14:35:43 -0800, Jeff Liebermann <jeffl@cruzio.com> > wrote: > >> The white stuff that leaks out of carbon zinc battery is the zinc >> chloride electrolyte: > > Oops. Zinc chloride is the crud that leaks out of the battery. The > electrolyte is ammonium chloride. >
Zinc chloride actually attracts so much water that it dissolves in it, as I found out when I tried to crystallize the stuff. Jeroen Belleman
On Mon, 12 Feb 2018 00:31:54 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

>On 11/02/18 23:38, Jeff Liebermann wrote: >> On Sun, 11 Feb 2018 14:35:43 -0800, Jeff Liebermann <jeffl@cruzio.com> >> wrote: >> >>> The white stuff that leaks out of carbon zinc battery is the zinc >>> chloride electrolyte: >> >> Oops. Zinc chloride is the crud that leaks out of the battery. The >> electrolyte is ammonium chloride.
>Zinc chloride actually attracts so much water that it dissolves in it, >as I found out when I tried to crystallize the stuff. > >Jeroen Belleman
What were you trying to make? Soldering flux (usually a mix of zinc chloride and hydrochloric acid)? Don't use it on electronics as it's conductive. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558