Flashlight cleanup, isle 3!

[prof student]

Well, I had finally bought a Fenix TK20 (last one from Optic Planet - thanks guys), and had Kirkland batteries running in there, Costco's brand.

Well, the light was dimming rather quickly, so I decided to put in a new set of batteries. Well, lo and behold, the tail cap was really hard to screw off. I didn't think I had screwed it on that tight. Well, anyway, when I finally got it off, the last battery had been leaking!!

Questions:

What is the best way to get the acid off? It is mostly on the tail end of the tube, on the inside and on the lip, AND there is a little bit on the INSIDE of the tailcap.

If I leave it on, will it affect the performance of the light?

Thanks for any help & info.

 

[Slartibartfast]

First off it isn't acid that leaked out, it is an Alkaline, most likely potassium hydroxide. To clean it up, grab a tooth brush and some vinegar. The acid in the vinegar will neutralize the alkaline deposit from the battery. Make sure to dry everything properly before reassembling and loading in your new set of eneloops. (You aren't going to put alkalines back into your nice light again are you???)

Good luck!

 

[onetrickpony]

My dad always used baking soda and water, it works great due to the slight abrasive quality.

If that doesn't work, just soak it overnight in vinegar like mentioned above, then try again. As long as there isn't any major corrosion, you'll be good to go.

BTW, alkalines usually won't leak until they're discharged. NIMH batteries almost never leak, and when they do, it's usually just a little dry powder.

And to answer your last question, yes it will affect the performance of your flashlight. It will add resistance or disrupt the current flow entirely, and it will eat into the metal eventually. Clean it completely and lube up the threads with petroleum jelly or something better if you have it.

 

[mdh1979]

+1 to vinegar and a toothbrush. Baking soda and water won't do a thing to alkaline, it only works to neutralize acid from a lead acid battery. Lube the threads and seal up with petroleum jelly and get it snug.

Matt

 

[onetrickpony]

I just meant for the abrasive, it's just enough to remove crud without damaging the surface. Works on teeth too.

 

[mdh1979]

I just meant for the abrasive, it's just enough to remove crud without damaging the surface. Works on teeth too.

Ah! You are right. I didn't think of that.

Matt

 

[prof student]

First off it isn't acid that leaked out, it is an Alkaline, most likely potassium hydroxide. To clean it up, grab a tooth brush and some vinegar. The acid in the vinegar will neutralize the alkaline deposit from the battery. Make sure to dry everything properly before reassembling and loading in your new set of eneloops. (You aren't going to put alkalines back into your nice light again are you???)

Good luck!

Well, I had a Scotch pad & was using it, but nothing was comming off. So, I soaked in in vinegar for a day. Will what the battery leaked out always leave a "stain" of sorts on the metal? It seems like the vinegar either ate or loosened most of the stuff. When I run my finger along the inside of the body & the lip, it feels pretty smooth, but the inside black coating has been "chipped" off - is that from the alkaline eating whatever it makes contact with, or did I leave in the vinegar too long?

I still have to do the tail cap. Any idead on how to tackle that? Not sure about how to disassemble a TK20 tail cap to get to the inside (where the threads are & around the spring) to clean up the leakage.

Yes, I FINALLY bought some Eneloops at Costco!!!! But not sure what use i will put the TK20 to, so I may actually end up buying some Energizer Lithiums if don't plan on using it often.

 

[Phil828]

Someone on another thread recommended a product called Deoxit. It is made for this type of problem. I haven't tried it myself yet but Amazon has it as does 4sevens.

 

[prof student]

Someone on another thread recommended a product called Deoxit. It is made for this type of problem. I haven't tried it myself yet but Amazon has it as does 4sevens.

Deoxit is to get that stuff off from when your battery leaks?

 

[stickx]

I have an old flashlight that had an alkaline leak so I though I would try the vinegar soak. It worked great at removing the battery acid - cleaned things right up. Thanks for the tip.

 

[Yoda4561]

Deoxit won't do better than any other quality oil when it comes to battery leakage. It's for removing surface oxides from copper, brass, and aluminum electrical contacts to improve function. Works damn good at that too, but not the first solution to battery leakage.

 

[Slartibartfast]

Well, I had a Scotch pad & was using it, but nothing was comming off. So, I soaked in in vinegar for a day. Will what the battery leaked out always leave a "stain" of sorts on the metal? It seems like the vinegar either ate or loosened most of the stuff. When I run my finger along the inside of the body & the lip, it feels pretty smooth, but the inside black coating has been "chipped" off - is that from the alkaline eating whatever it makes contact with, or did I leave in the vinegar too long?.

That pitting in the anodizing is from the potassium hydroxide. A strong base is what is commonly used to remove anodizing from aluminum, you just have to be careful how long you leave it because it will eat the aluminum too.

Sorry can't help with taking apart the switch.

 

[Battery Guy]

Well, I had a Scotch pad & was using it, but nothing was comming off. So, I soaked in in vinegar for a day. Will what the battery leaked out always leave a "stain" of sorts on the metal? It seems like the vinegar either ate or loosened most of the stuff. When I run my finger along the inside of the body & the lip, it feels pretty smooth, but the inside black coating has been "chipped" off - is that from the alkaline eating whatever it makes contact with, or did I leave in the vinegar too long?

You did not leave it in the vinegar too long. The caustic electrolyte from the alkaline battery will aggressively attack the aluminum in the flashlight body, including the protective anodized layer. The best advice I can give you is to soak the area exposed to caustic electrolyte in vinegar for a few days, then rinse with several dips in clean water, wipe off with a clean towel and apply Deoxit to the surface. The surface will always be "stained", but hopefully with sufficient cleaning, the performance of the light will not be affected.

Cheers,
BG