What is the Most Efficient, Powerful, Safe Acid to Neutralize Alkali Compounds...?

[LEDAdd1ct]

I have a six "C" cell Maglite. Suffice it to say, it was not easy to get.

It contains five leaked alkalines. I want to rescue this light.

I read the following threads:

One
Two
Three
Four
Five

To different degrees, they involve individuals who have successfully rescued Maglites from leaked alkalines, and those who gave up and discarded them. It is not my intent to discard this light.

This brings me to my key question and the thread title:

What is the most efficeint, powerful, safe acid I can use to neutralize the alkali compounds and get the batteries out?

Thought various tooth-eating acidic sodas are recommended, I don't quite feel that is the most powerful acid.

 

[TinderBox (UK)]

this might be stupid, but what about normal household vinegar?

John.

 

[Kestrel]

"Safe" acids are pretty much the opposite of 'powerful' ones.
'Weak' acids only partially dissociate in water. As acids such as these neutralize a base, they dissociate further to maintain equilibrium. IMO this is the route that you would want to take.

A stronger acid than this will tend to attack any aluminum present rather than gradually neutralize any alkaline compounds.

One quick google search return to start with:
http://www.ausetute.com.au/ka.html

My two pH's, FWIW.

 

[LEDAdd1ct]

Thanks, guys.

This easy PDF guide puts lemon juice as having a more acidic pH than either soda or vinegar.

Looks like I'll be grabbing a couple bottles of lemon juice on the way home.

Tried loosening the switch and pushing the switch assembly up with no luck.

Will report back...

 

[TinderBox (UK)]

Is there any danger of a reaction, when acid and alkaline is mixed? , should you work outside?

John.

 

[LEDAdd1ct]

Hmm...good point. 8:26 PM in the UK, but only afternoon where I am...lots of daylight.

Thanks, John.

I'm going for a walk and will pick up some lemon juice on the way home.

I'll try pouring some down the Maglite barrel, outside, when I return.

As an aside, the fact someone situated on a different continent and someone on the other side of the same continent can all collaborate on removing stuck alkaline batteries via acid is truly a testament to the information age.

 

[TinderBox (UK)]

Lemon juice in the UK, the strongest comes in the little yellow plastic lemon shaped container, but you don't get much for your money compared to vinegar which is cheap, i dont know what the price of these item are in the US

I dont think the watered down drinking lemon juice is going to be strong enough.

John.

 

[LEDAdd1ct]

Hmm...a big bottle of vinegar per CC/fluid ounce may be cheaper than a smaller bottle of lemon juice.

Will see what the first ingredient is and price and base decision off that.

Be back in a few hours...

 

[Mr Happy]

Try kitchen/bathroom limescale remover. You could try white pickling vinegar at first and move onto the limescale remover if the vinegar doesn't work. But don't mess around with lemon juice, it has all sorts of messy, non-acid stuff in it.

As for damaging the light, don't be too worried. Aluminium is quite resistant to acid, especially if it has an anodized finish. As long as you rinse the light thoroughly in clean water when you are finished and don't put it away with acid inside it no worse harm will come to it than already.

Your biggest problem will be mechanical. When alkaline batteries leak they swell up, which is why they are stuck in the tube and won't move. Acid won't help unstick them. Your best bet might be to go outside, lay down lots of newspaper, and go at the batteries with cordless drill from the tailcap end. Mechanically drill and dig most of the batteries out, then ream the inside of the tube, and save the acid for the final clean up. Since it's a 6C light you might need to get a long boring drill bit to reach all the way down.

 

[StorminMatt]

I dont think the watered down drinking lemon juice is going to be strong enough.

My thoughts exactly. You're probably better off using vinegar than your average lemonade (which is HIGHLY watered down lemon juice, if it even contains any real juice at all). If you want real, unwatered down lemon juice, you're going to have to get some lemons and squeeze them. Unless you actually have a lemon tree, this is going to be cost prohibitive.

 

[LEDAdd1ct]

I bought one of those ubiquitous (in the U.S.) green translucent bottles of lemon juice, and started by dripping some into the bottom of the light. The bubbles and hissing indicated all sorts of interesting chemistry was going on. Next I poured some in the switch hole (rubber cap removed) and finally right down the top of the light. Hissing and bubbling and smelliness abound.

I inverted the light in my bathroom sink, and poured some more in, and I am going to let it sit that way.

I don't own a drill.

 

[Yamabushi]

If you're going to use a kitchen product, white vinegar (the cheap, industrially produced acetic acid + water mixture) is best. It's relatively pure and rinses off clean.

The problem with natural products such as lemon juice is they contain sugars, pulp, essential oils, etc. Likewise, don't use malt vinegar, wine vinegar, cider vinegar, etc.

 

[Kestrel]

IMO lemon juice smells WAY better than vinegar.

 

[LEDAdd1ct]

My bathroom is filled with a pretty scent.

However, I would forgo the pleasant smell for no more stuck batteries.

I checked after letting it sit a few hours, and the lemon juice is just sitting on top.

It is not seeping down past the cells.

Can anyone clarify as to whether the pre-C Maglite switch assembly comes out through the top or bottom?

 

[Mr Happy]

Can anyone clarify as to whether the pre-C Maglite switch assembly comes out through the top or bottom?

I think you can tell by inspection. On some Maglites there is a C-ring in a groove at the top of the light that stops the switch assembly coming out the top. If you remove this C-ring the switch should pull out. If there is no C-ring, then I don't think there is anything to stop the switch/bulb assembly coming out as long as you have fully retracted the grub screw that holds the assembly in place.

 

[LEDAdd1ct]

I inserted a 5/64" hex wrench and tried rotating counterclockwise to loosen it, but I honestly can't tell whether I was successful.

Were I, I could potentially borrow a hammer and metal rod and bang them out from the top.

 

[Mr Happy]

I think you will know if you are successful as the switch assembly will get loose. Also, you can tell if there is anything stopping the switch assembly coming out by looking. If there is no obstruction visible in the top of the light it will slide out.

 

[LEDAdd1ct]

There is alkali "superglue" all over the switch assembly; pouring the lemon juice in there resulted in copious bubbling.

That is why I am not sure if I was successful.

I will try again.

EDIT: Before beginning, the outside of the switch was caked in alkaline powder, and the mechanism would not engage. Now, the outside is clear of the powder, and it switches 100% of the time cleanly and crisply. If I were certain I loosened the set screw, I would borrow a hammer and bang the cells out from the top.

EDIT TWO: I suspected that on the older, no "C" models the switch assembly came out the top, because I felt like I read it somewhere. Here we go:

Link One
Link Two

 

[VidPro]

Try kitchen/bathroom limescale remover. .

CLR (calcium lime rust remover), is at least 2x more powerfull than vinegar, and nothing safe about it should use gloves. The commertials like to show the use of it without gloves, so they dont scare people. but gloves is the only way to really use it. The use of a strong acid, wont get desired results, we would even water down vinager to do the nutralising, to keep corrosion from acid down.

Everything in Mr. Happys post #9 covers is perfectly. Any kind of drill, even a cheap one, and a Bit for drilling through joists, big long bit. without drilling out no acid will get that stuff out of there , before things in there are ruined.

A strong acid is totally unnecessary, because generally it would be used to only neutralize the small ammount of goo after you cleanup. just like any alkaline from soap to Lye, you can rince out most of it with water. then neutralizing the small ammounts to stop further progressions over time. Rince rince rince. To get the bulk of the battery out , trying to eat through it isnt going to "save" the light.

I have used CLR to remove (cpu heat sync) anodizing completly so at least some types of anodizing can be stripped with an acid or a base. Mag anodizing though acts more like paint, so i am not sure about it.

 

[LEDAdd1ct]

Thanks, Vid. I walked away for 30 minutes, and I can still hear the lemon juice bubbling and popping when I lean over,
so it is still doing its thing.

I need the spanner wrench to remove the top ring.

I think it would be good to have on hand, not just for now, but for future use.

If anyone has a "C" size Maglite spanner wrench I could buy for a couple bucks, please email me.

I think once I remove the switch assembly from the top (after removing the retaining ring) I can simply bang them out with a hammer and wooden/metal dowel.

Anyone who has felt the pain of alkaline batteries knows this suffering.

At least this light does not have sentimental value, i.e., I just received it the other day.