Best way to reclaim pencil zinc plugs

Anyone....

When I change pencil zincs in my engines and transmissions I try to discard the old zinc and reload the bronze plug with a new zinc. I usually get three or four of the used zincs to break off inside the bronze plug making them unusable. I know they are not terribly expensive but I was wondering if they could be reclaimed without spending more time than they are worth. In my case drilling and re-tapping is not worth the effort because I do not have a drill press or large vise and a shop area. I do have a battery charger and a small vat of saltwater. Is it possible to connect the plug to 12V positive and 12V negative to a cathode and submerge them in salt water and get the zinc to remove itself from the plug? I have a bunch of these plugs that are waiting to be reclaimed. Thanks for any help.

obthomas said:

... I was wondering if they could be reclaimed without spending more time than they are worth.

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Soak them in muriatic (hydrochloric) acid for a few minutes. You can get the acid by the gallon from a pool supply or at a Home Depot type store.

Do it outside in a plastic bucket, stand upwind and to the side, don't breathe the fumes or you will regret it, it is dangerous stuff to play with but highly effective for your purpose.

Sometimes the savings are hardly worth the risk.

You can also use a propane torch. The zinc will melt quickly and you can "shake" it out. Once it's cooled you screw in the new one. Vice grips and a pail of water are a help.

Larry M said:

You can also use a propane torch. The zinc will melt quickly and you can "shake" it out. Once it's cooled you screw in the new one. Vice grips and a pail of water are a help.

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Probably the best idea. It's a pain picking out the slag and crap that seems to sometimes stick though.

Be careful of the propane torch idea...I have read where if a drop of water is un there wo will wind up with molten zinc all over (hopefully not you).

When I did it...sure enough the first one popped and blew zinc all over...I was 10 feet away and still got a little splatter that hit one arm...

Not for me anymore.....I'm careful how I load the zincs and replace early enough that the threads are still enough to vice grip out. Once you buy 3-4 brass caps...you have enough to last awhile as you can usually get the zincs out of at least half of them.

I'm sure if you bought a melting crucible they use for melting lead for sinkers and covered it...you would be fine....still too much od a PIA for me.

Best is to replace the zincs before the get to that point. It’s a waste of time trying to reuse the plug.

If you pencil zincs are going fast, you might also what to find out why?

Thanks for replies.

My hull zincs last about 9 months. My engine zincs about the same. I replace them when they are about half gone. At half gone a few of them break off in the plugs when I try to reload. To replace them sooner is not more cost effective nor a guarantee that the zinc will not break off anyway. I have about a dozen plugs that need help. I'm going to live dangerously and try the muratic acid in a plastic bucket downwind and away.

Phil Fill said:

If you pencil zincs are going fast, you might also what to find out why?

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They probably have the high-reactivity inserts with the wire core that self destruct when they get wet. That kind last forever if you keep them dry.

Greetings,
Mr. obt. Atta boy! Don't forget the safety glasses/protective gear. You can buy the muriatic acid in 1 qt. sizes. No need for a gallon unless you plan on cleaning out your heat exchangers/coolers.

Greetings,
Mr. Rick B. This is what is happening on the molecular level with those highly reactive inserts with the wire core and why they go so fast....sanger.dk

Silly Firefly ... everyone knows it is the result of metal eating bacteria released into the environment by a crazed Canadian.

When the stuff reaches groundwater and flows into the sea it heads directly to the warmth of the nearest heat exchanger where it thrives on the zinc.

http://www.dnimetals.com/PDF/2012-03-05_Reuters_ore-eating-bacteria.pdf

Greetings,
Ahhh...so...As usual, you're succinct and to the point. So more like this then?

Metaphorically speaking.....

Know anyone who is into reloading gun ammunition, muzzel loaders or making fishing lures? They may have a small electric lead furnace that you can use.

I bought a small furance off Ebay a few years ago for $30 which works great. (Lead melts at a lower temp. than zinc, 327 verse 787 degrees, you have to be sure the furnace will run that hot before you buy one.)

Drop your old bronze caps in the empty pot for 30 minutes and the zinc runs right out. I also melt my old zinc hull and shaft zinc down and pour into pencil zincs. Use an appropriate sized thread chaser to thread the new pencil zincs and clean up the plug threads for a good contact.

Thats a winter project once every few years when you have absolutely nothing else to do.

When I was a kid, I'd collect scrap zinc from boat yards, put it in a bucket of acid, put a garbage bag over the bucket and let it inflate with the hydrogen gas coming off the zinc. Then I'd tie a sparkler to the bag, light the sparkler and watch it fly away. Let's see, that's acid, hydrogen gas and fire. I'm sometimes surprised I survived my youth.