Removing battery corrosion

My sovereign cleaning method for this is to use a very strong concentration of baking soda mixed into distilled water. About a tablespoon of soda into a teaspoon of water to make a paste. This will neutralize any corrosives f rom the batteries - but the material is highly conductive in its own right. So, after application with a small toothbrush or spiral brush, rinse again as yo have with distilled water, then alcohol to displace the water.

If severe, and the alternative is landfill - I have been known to run an en tire chassis through the dishwasher (one without an exposed Calrod), or use a bit of lye-based oven cleaner on a cotton swab - again rinse carefully w hen done. Needs must when the devil rides.

Peter Wieck Melrose Park, PA

small toothbrush or spiral brush, rinse again as yo have with distilled water, then alcohol to displace the water.

As most of the batteries used in portable devices are some type of alkaline the baking soda is the opposit of what should be used. White vinegar is what you should be using to neutralize it.

I am not sure what the very old carbon zinc batteries used, it may have been a from of acid. I know the car batteries use acid and the baking soda is good for that. Just not good for the newer smaller AA,C,D type batteries.

entire chassis through the dishwasher (one without an exposed Calrod)

Back when projection TVs were plagued with coolant leaks, I used to soak th e entire circuit board in an ammonia and soap solution. But *first*, every thing that can trap water must be removed. Back then, that meant SMPS tran sformer, HOT and flyback XFRs, inductors,etc. A lot of work but it fixed s tubborn symptoms and no call backs.

In a transistor radio, this means removing the IF transformers, audio trans former, and even removing the gang tuner is a good idea.

I did one yesterday, got what I could off some bent flat strip with a screw driver, got the remainder off with a grinder. A dishwasher is more often th e suitable treatment, but as has been said there are some parts definitely not dishwashable. Speakers, unpotted relays, variable caps, paper caps, tra nsformers, some other stuff.

NT

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:

--
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

Ralph Mowery schrieb:

[...]

Full ack!

Regards

Reinhard

Since this layer is alcaline, the best to use an acid ; vinegar for instance.

LeClanche cells are acid-based (Ammonium CLoride) with an acidic pH (depending on the age of the cell) from about 6 (nearly dead) to about 4.6 (fresh). Hence the pointer to baking soda.

Baking Soda (Sodium Bicarbonate) is about pH 8.4 when dissolved in water. Household vinegar is pH 2.4, and will tear copper apart.

The neutralizing agent wants to be slow and mild. Vinegar (acetic acid) is pretty strong.

Peter Wieck Melrose Park, PA

Yep. The white stuff from an alkaline cell is potassium carbonate and has a pH of about 11 in water: 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: 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: 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

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

This makes sense, but I have to ask why regular tap water wont work V/S distilled water? I know that adding water to a car battery should be distilled, (so it dont have any minerals), but in this case, it would seem that any clean water would work.

But maybe I am missing something. Yet, I do try to eliminate unnecessary expenses, and distilled water adds to the cost, not to mention an extra trip to a store, since it's not something I keep on hand.

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.

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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

Nah! Just part of a high school chemistry course 45 years ago.

Jeroen Belleman

unnecessary

What do you put in your steam iron? That's where most of my distilled/de-ionised water goes...

Mike.

Steam iron? Do they still use those things? I recall my mother using one in the 1950s and 60s....

Either way. blue jeans and flannels shirts dont need ironing... That's about all of us rural folks wear, aside from our camo hunting clothes.

I did once hear of a guy trying to iron his birthday suit, after drinking a lot of shine.... Luckily his wife ironed his head with a cast iron frying pan before he damaged too much of his birthday suit. and she then sent him to bed.

the entire circuit board in an ammonia and soap solution. But *first*, eve rything that can trap water must be removed. Back then, that meant SMPS tr ansformer, HOT and flyback XFRs, inductors,etc. A lot of work but it fixed stubborn symptoms and no call backs. "

I had a different technique. I washed it in hot water, then alcohol, then a cetone with a brush and then blew dried it on hot to evaporate everything. And then sprayed with spray solvent to make it cold. That squeezes the shit out of the board, which is quite porous. Repeated about 4 times. The last time left the acetone or alcohol on it, heated it up with the blow dryer an d waited a while until you could not smell it anymore.

The worst part was when it corroded the copper traces. Can't solder to them , must get all the way to the point where it is no longer dark and add a ju mp[er.And also extra clean that area because there is more conductive shit in it. It is actually in the board and you can see bubbles when you heat it .

I remember old AA and AB GE chassis bubbling under the solder on the griple tts which impeded their soldering. And those were about 90 % of the problem s with those sets.

That's acid plumbing solder for copper pipes.

But you brought up a question. Electrical solder is rosin. What exactly is roisn and how does it work for a flux? Is it the same thing used for playing a violin, which as far as I know, is made from pine tree sap?

that's what it is. Just take pine resin & heat to drive off the volatiles. You can get 25-50kg resin per tonne of wood pulp, but only from pine. Spruce gives less.

NT