Help cleaning old flashlight...

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gcbryan
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Location: Seattle,WA
Help cleaning old flashlight...
I got an old flashlight today that I got for less than the others and now I know why Smile

It isn't in as good a shape as the others. It's rusted on the inside and particularly on the spring in the tail cap. I'm not sure whether the switch is rusted as well but at least it moves.

The plastic bulb holder is missing as well. I took the reflector and lens off and poured some vinegar and baking soda through the body of the flashlight and soaked the tail cap and spring in it as well.

I used an old toothbrush and brushed the inside of the tube and the spring and tail cap and then washing everything off with warm water and let it dry. The tail cap spring is still rusted particularly the small coil that actually makes contact with the negative terminal of the battery.

I put a light bulb in and some batteries and turned the switch on but it doesn't light up. However if I remove the tailcap and use a piece of metal between the negative battery terminal and the side of the flashlight it does light up.

I'm not sure if the problem is the switch or the tail cap spring but the spring is a good starting point. What is the best way to clean rust from that spring other than what I've done?

Ecosys
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Put some white vinegar in a coffee cup and heat it in the microwave until hot, drop in your spring and don't walk away, rust should be gone in just a couple of minutes. Then drop it into a cup with water and baking soda to neutralize the acid, rinse with water, dry and quickly coat with a light oil to prevent flash rust from forming.

Or you could just use some CLR, Naval Jelly, Citric acid or some such?

Hope that helps,

Trig

gcbryan
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I'll try that regarding the spring. I did a good enough job just using sandpaper that the light now comes on. The problem now is that is doesn't go off!

The switch moves (3 position side sliding switch with momentary button) there must be rust somewhere in the switch making contact? even when the switch is off.

Any ideas on how to clean an old switch like that that can't be removed since they are held on with a rivet?

[Update] I used a toothbrush and just scrubbed anything I could reach inside the tube. There was more rust in there then I thought. Now the light and switch work!

There's still some rust so I guess I'll continue until I can get most of it out. I run out of vinegar Smile

I used some putty to replace the plastic holder for the bulb. I thought this light was going to be green like my other one but it's black with the same pattern.

This one has been a little more "fun" than the others since I've had to do something to clean it up!
dthrckt
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the best way to clean rust is evaporust.

if there is one thing in this world I hate, it is rust.  I live in NY and the salt they spread on the roads has destroyed a few motor vehicles I would have otherwise had MUCH longer.

Also, I am a gunsmith (professionally, in the past, and again...someday) and for some stupid reason, guns are still made from non-stainless steel.  Evaporust is the best way to prep a gun for refinishing when a customer won't pay for manual (abrasive) resurfacing - just clean rust and reblue, pits and all.

Occasionally, harbor freight has 1 gallon on sale for $18, but for club members only.  They used to charge 20, then 25, now 30.

The cheapest I've found it is 5 gallons/$90 (free shipping). www.oreillyauto.com

They have quart and gallon at the cheapest prices I've found but you pay shipping (unless there's a B&M near you).

So...this stuff works great.  You submerse your rusty stuff in it over night, 24 hours if heavily rusted, and the rust just disappears.  It is not corrosive, like vinegar is (ever get that in your eye?  holy F@#$ that stings) - it doesn't hurt anything I've ever put it on, except rust.  If you don't rinse it off it leaves a thin film - that's great if you did a can of rusty nails (the film offers a little protection to bare steel), but if you do something w/ close fitting parts you'll want to rinse it off.  Just be sure to dry and or oil so it doesn't rust again.

Oh, and you can use it over and over.  I've actually never worn out a gallon...I just lose enough from spilling/evaporation, etc. that I get more and dump the little I had left.  It does get weaker...but that means the part just has to sit longer.

Brush off the loose rust and it will last even longer (and work faster).

The only downside is that you need enough of the stuff to submerse your part.  I've read of others setting up a recovery tank/shower type system to do bigger stuff.  I might try it myself on a '71 ski-doo very soon.

But for flashlights, except the biggest spotlights, that's hardly an issue.  You could do sooo many flashlights with a quart and the right size pvc pipe:)

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gcbryan
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Sounds like good stuff. I thought I had my light working including the switch but there is still enough rust that the light just stays on so I'll be working on this one for a while!
dthrckt
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I had some alkalines leak in a dorcy aluminum light and it stopped working.  The thing was anodized but the acid? ate through that in corroded the aluminum, too.

The tailcap was installed permanently by factory so I couldn't get to the tail spring, which was also a mess. 

I tried just about everything under the sink - which is much more than average - and nothing worked until "Tarn-X".  It actually says on the bottle not to use on aluminum, but I've used it on an aluminum carburetor overnight w/o issue (made it slightly darker color).  I just filled the battery tube, let it sit a few hours and the white crud just disappeared.

Maybe you just need to dry it out real well and it will shut off?

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