Mystery Of The War Nickel

[GB_Amateur]

2 minutes ago, schoolofhardNox said:

On the Manticore, I ran some numbers for you. I was inside, so sensitivity was at 13. I had discrimination, but it would not affect the readings as the signals were pure with no bleeding into the disc zone. I did not reset the machine, as I didn't want to lose my settings. So not a standardized test by any means. I tried both nickels, so the first number you see is the less corroded one and the second number is the more corroded one. AT Gen - 46/49, AT Fast- 46/49, AT LC - 47/50, AT HC - 48/50, AT Trash Reject - 46/49, Beach General - 46/49, Beach LC - 46/49, Beach Deep - 46/49, Beach Surf & Seawater - 45/48, Goldfield - 45/48. Numbers jumped sometimes with the low number at 45 and the high number at 50 (occasionally jumping to 53).

Wow, thanks for the quick response!  Do you realize you've just solved a mystery that has been floating around this site (and other detecting sites) for quite a few years?  I'm serious.

There have been multiple reports of Warnicks giving considerably higher VDI's than other nickels, even though no one has ever given evidence that Warnicks *not* coming from the ground read anything different than standard 25-75 Ni-Cu.  (I measured over 150 in my non-detected collection with the Eqx and all were either 13 or (occasionally) 13-14.

The Manticore's USA nickel VDI's peak around 26-27 so your recent two are way above that.  (And they are consistent with many of the earlier reports of coins which were found in the ground, but not in saltwater.)

The environment has seriously changed the conductivity and selective removal of manganese (9% of the Warnick and a very low conductor) is pretty much now the solid explanation.

[schoolofhardNox]

38 minutes ago, GB_Amateur said:

Wow, thanks for the quick response!  Do you realize you've just solved a mystery that has been floating around this site (and other detecting sites) for quite a few years?  I'm serious.

There have been multiple reports of Warnicks giving considerably higher VDI's than other nickels, even though no one has ever given evidence that Warnicks *not* coming from the ground read anything different than standard 25-75 Ni-Cu.  (I measured over 150 in my non-detected collection with the Eqx and all were either 13 or (occasionally) 13-14.

The Manticore's USA nickel VDI's peak around 26-27 so your recent two are way above that.  (And they are consistent with many of the earlier reports of coins which were found in the ground, but not in saltwater.)

The environment has seriously changed the conductivity and selective removal of manganese (9% of the Warnick and a very low conductor) is pretty much now the solid explanation.

I'm wondering if the copper oxide crust is raising that number considerably. If I get some time this weekend, I'll try a normal non oxidized war nickel and see if it reads closer to 26. It seems the more refined detectors become, the more number variability they take on. Bring back the E Trac set to maximum spread. 😅 There was just enough difference to mostly tell silver from clad (even Wheats from Memorials).

Ok, I couldn't wait 🙄. So I tried a war nickel that was clean and it read 28. So far so good, just 2 numbers higher that a Cu-Ni one. But then I started to think maybe the copper oxide is raising the numbers to be more and average of copper and nickel. So then I thought what if the black encrusted ones I find are silver oxide on the top making it black.They should read even higher. But the findings surprised even me. These four new nickels are from the same beach different year's hunt. both the top left and bottom left are black, the only difference is one is clean and toned black (corrosion cracked off), the other is raw thick black (not having the corrosion cracked off). The top right and bottom right are different levels of the green corrosion. What is going on here??? I think I was in goldfield mode.

[GB_Amateur]

I don't think oxides are conductive.

A big component of metal detector response to a specific target is skin depth.  Basically how deep the electromagnetic field penetrates.  Pretty sure this is why our modern USA clad coinage reads so high -- because the Ni-Cu layer has a (relatively speaking) high skin depth and is in a sense transparent to the dynamic EM fields.

The Warnick was a brilliant solution for the metallurgical engineers who designed it.  The dominant coin in coin-operated machines in the early 40's here in our country was the 'nickel'.  Apparently the machines had a way of detecting slugs and it was something akin to our modern detector.  (There may also have been ways of detecting the weight.)  When word came out that the nickel's comp was being changed for the war there was an outcry from the coin op industry asking that the replacement match not only the weight but also the EM properties.  Amazingly they were able (in a short time) to do that by adding manganese -- possibly the lowest conductor of all non-radioactive metallic elements -- chosen to moderate the higher conducting properties of the silver and copper.

My hypothesis has been that if the manganese can somehow be removed (chemically) while the coin is in the environment then the conductivity will increase to reflect the remaining copper and silver.

Can you use an abrasive (e.g. steel wool) to take off the surface crud from one AFTER you've measured its VDI and see how the VDI changes?  That should tell you if you're noticing a surface effect or if it's rather a global change.

Sorry to be putting all this work on you.  If I were out there near the NE coast I'd help.  😉

P.S. My hypothesis doesn't explain the 20 and 22 ID's of those two coins in your photo above so maybe multiple processes are present.  Or maybe my hypothesis is just full of, uh, corrosion....

[schoolofhardNox]

I'm going to start a discussion on this issue on the Manticore forum, so maybe other beach Manticore owners can try this as well. I ran some more tests and I'm more confused now than ever. 😳 Steve or anyone who can move some of the posts from here to there, it would be appreciated.

[schoolofhardNox]

So I have been posting my beach detecting series mostly using a GPX, but sometimes the Manticore. Recently discussions got around to trying out the war nickels on the Manticore, doing an air test to see if they read the same as a non dug (clean) war nickel and also how that compares to a CU-Ni modern nickel. This is a continuation of those discussions now posted in a more appropriate forum. I was running the Manticore in Goldfield (but ran it in every other mode) with just about the same results. Sensitivity was set to 13  as I was in my house. It ran very quiet and all targets were solid, non bleeding and on the line targets, on the screen. Nice round blobs. For this test I ran a bunch of war nickels that were from the same beach, over a span of around 6-8  years. The first test was done with them uncleaned. I separated them into 3  general categories: black toned/black encrusted, green encrusted, white/ mostly white. Here are the Target ID's (Black toned - 23, 15, 23, 21, 16, 16, 20--- Black encrusted - 80), /// (Green encrusted - 23, 25, 49, 31, 44, 38, 70, 45, 32, 11, 43, 52, 46, 68, 35, 56) ///  (White or mostly white - 25, 27, 34, 24, 26, 45) As a reference, I scanned a non beach clean war nickel and it came in at - 28. Also a modern clean (CU NI) one that came in at - 26.

I then took one of the black nickels that read 16 and cleaned it until all the black toned color was removed. It still read 16 - no change. So I took the black encrusted nickle that read 80 and cracked off the black coating and brass brushed it and baking soda steel wooled it, but could not get it completely silver, but almost. It now read 80 - no change.

I have absolutely no idea why these nickels read all over the place. I first thought that the green crusted was more copper based - copper oxide, so it should read higher. I also thought the black crusted ones would probably be a silver oxide and would read even higher. At first it looked like that, but now it seems the coating has no repeatable effect on the target id.

Any thought on this? This picture is one of the first experiment I did on the issue with just 4 nickels (not included in the list above).

[GB_Amateur]

Here's the post that m/l started the discussion.  See also the posts that follow it:

 

[Dug D]

I will chime in to say that jumpy signals on both good and bad targets takes away the fun.🙁

My wish list for an update starts with less jumpy signals on good targets and second how about a little work on the depth gauge, three arrows should not be 2 inches deep for a coin. After the update the depth gauge seems way off.   I think these are both software fixes that are realistic. 

[JCR]

I too have recently been testing TIDs on War Nickels trying to set up a custom tone program for the Rutus Versa & prettying up the one I have on the Legend to not miss these coins trying to skip pull tabs. All of mine are ones that I have dug. Over 8 coins the spread is very wide, from just above a regular Nickel to Low IHP range.  Frustrating, but good to know. Obviously the alloy content varies a good bit. I haven’t yet decided how many pull tabs a War Nickel is worth.

[steveg]

There was a post on here, years ago, about war nickels.  I was a part of that, and had some examined using XRF.  Bottom line, the are EXTREMELY variable, in terms of ID.  Some ID near, or just a hair above, a standard nickle.  Others read at various places through the pull tab range, and others up as high as IHP/zinc pennies.  As JCR noted, it likely has to do with the alloy content (as XRF showed), and it's also probably the different alloys that affect, at least in part, the type of crud/oxidation that forms on the different coins.

Steve

[JCR]

None of the War Nickel I have dug had any serious corrosion. The discoloration varies some. I may have time to see if there is any correlation.