Zincs - Salvaging NPT Brass Plugs

[Blue Stocking]

Originally Posted by HopCar

Sulfur and Zinc Dust = Rocket Fuel!

OOOHHH yeah BABY !!!

[Cuttyhunk]

You are giving me flashbacks to my hunter safety course...it was all 14 year old boys and their fathers, plus me ( middle aged woman) and my husband. To emphasize how important gun safety is, the instructors plus the fathers and husband started telling stories of all the really stupid things they did with guns when they were young. I think for the 14 year olds, it just gave them bad ideas...but it sure scared the crap outta me!


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[a64pilot]

I tried the gun cotton thing and got not result whatsoever, acids didn't smoke so maybe they were weak?
The trick to the Iodine thing is to filter the crystals several times with the same ammonia, and get high strength pure ammonia. I think photographers use it for something?
My black powder wasn't very explosive, I've wondered if I should have watered it and let that dry and re-ground that or something as just mixing the three powders burned, but just wasn't very explosive.
At work we "debur" aluminum by sanding the skins, being Alclad, this leaves a very fine pure aluminum powder, mix that with ammonium nitrate and you have a powder that is very explosive when shot with a high velocity bullet, called Tannerite, I think?

[HappyMdRSailor]

Oh man...

You tee'd it up and struck out!

Tannerite ... Ammiright?

[HopCar]

"My black powder wasn't very explosive, I've wondered if I should have watered it and let that dry and re-ground that or something as just mixing the three powders burned, but just wasn't very explosive."

I had the same problem. I knew you could wet it, form a paste, let it dry, then grind into small grains but I never tried it. I just remembered this is called "corning" the powder.

"very fine pure aluminum powder, mix that with ammonium nitrate and you have a powder that is very explosive when shot with a high velocity bullet, called Tannerite, I think?"

Very cool. I didn't know about this so I had to look it up. Sounds like this is pretty easy to buy. I've even seen it advertised but didn't realize this is what it is. Apparently you were not making Tannerite but a simpler version of it called Ammonal.

I haven't thought about this stuff in more than forty years. Now we've got the NSA watching us!

Hi boys! Keep up the good work!

[HappyMdRSailor]

Originally Posted by HopCar

"My black powder wasn't very explosive, I've wondered if I should have watered it and let that dry and re-ground that or something as just mixing the three powders burned, but just wasn't very explosive."

I had the same problem. I knew you could wet it, form a paste, let it dry, then grind into small grains but I never tried it. I just remembered this is called "corning" the powder.

"very fine pure aluminum powder, mix that with ammonium nitrate and you have a powder that is very explosive when shot with a high velocity bullet, called Tannerite, I think?"

Very cool. I didn't know about this so I had to look it up. Sounds like this is pretty easy to buy. I've even seen it advertised but didn't realize this is what it is. Apparently you were not making Tannerite but a simpler version of it called Ammonal.

I haven't thought about this stuff in more than forty years. Now we've got the NSA watching us!

Hi boys! Keep up the good work!

I was just about to post this when I ran across your comment...

Dear NSA, Dept of State, Homeland Security and local law enforcement:

The following people in this thread are reliving their youthful indiscretions of the explosive kind and have no intentions of utilizing this information for any unwillful, unlawful, or un-American intent...

HopCar
Jim Cate
Blue Stocking
HappyMdRSailor
A64pilot
Wotname
Cuttyhunk


It was just plain too much fun to hear things go boom when our moms weren't lookin'...

[Nicholson58]

Originally Posted by St. Elsewhere

This tip plus JD1's suggestion to carefully drill out the old zinc, has been some of the best advice that I have received here. I needed two bottom taps a bit larger than suggested. If bottom taps were not suggested, I might have gone for ordinary taps that would not have reached the "bottom" of the internal threads in the plugs. I was able to salvage all of the brass NPT zinc plugs that I have accumulated without a great deal of effort.

Thanks CF! What a great resource!

Make your own bottom tap by grinding off the tapered end. Its what we do in the machine shop. Also, if you change the zincs sooner you can avoid the problem. If there is no zinc, look in your heat exchanger for the scraps.

[a64pilot]

Speaking of Zincs, my Yanmar 4JHE doesn't have one, apparently that model doesn't.
Should I drill and tap the manifold and add one, or is there something peculiar with this ones design that a zinc is un-necessary?

[David M]

Acids dissolve zinc. I have never tried salvaging those plugs but I would first try letting them soak in vinegar for a few days. If that does not work then go up the scale to stronger acids. I would next try phosphoric acid, which is what is used for the part B solution in teak cleaner kits. HCl might be overkill which I would try last.

[David M]

Originally Posted by a64pilot

Speaking of Zincs, my Yanmar 4JHE doesn't have one, apparently that model doesn't.
Should I drill and tap the manifold and add one, or is there something peculiar with this ones design that a zinc is un-necessary?

Generally exhaust manifolds don't have anodes because the water-iron-anode electrical continuity is not continuous, even when the engine is running. The salt side of your heat exchanger should have an anode as should the salt side of a intercooler if you have a turbo diesel. Iron exhaust manifolds eventually corrode away from the inside. This will happen anode or not. Look into a stainless steel exhaust manifold for the next time. My stainless steel manifold is on its second engine now...yes, it outlasted an engine.