Iron Readings

[Anonymous]

Got a couple questions, Kinda, I have an area I look that is full of iron, mostly nails and decaying tin. This place reads in the 80's however if you hit a clean spot it reads in the 40's. Minerals that affect a metal detector are basically iron , right ?? Well in this area I can't run a gain higher than 9 if that high. Now there is another area near an old single room school house and the whole area reads in the 80's but I can run a +1 gain, what is the difference ?? Also anyone noticed an iron target at the edge of the search coil will give a high tone ?? Thought maybe it was 2 targets but dug a big nail and the signal was gone. But on the same hand have gotten a mixed high low tone over a target and found a bunch of old wheats mixed in with iron trash. Anyways just curious to see some replies.
Ray

 

[Anonymous]

Webster says "Minerals are solid homogeneous inorganic substances occurring in nature having a definite chemical composition." Digger says: Iron is a good example of a metallic mineral we find in the soil. I've read articles about actually picking up measureable amounts with a magnet simply by dragging it across the ground. In addition to what "Mother Nature" put into the soil, all those "man-made" rusted nails around that old foundation have an effect on the mineralization level of the yard you are hunting. That oxidized iron leaches right out into the soil. But so does the nitrogen fertilizer you put on your own yard each spring. That changes the mineralization level. The garden area is probably mineralized even more than the yard due to the frequent doses of miracle grow and decaying plants. Or decaying animals. Even watering the yard changes the mineralization level. Water is full of minerals. Hard water. Iron? Soft water. Sodium? Ever drink the water in many places that have oil wells? Sulfur!!! In addition to Mother Nature, man-made chemicals such as fertilizers, herbicides and insecticides have made a dramatic impact on readings I find around here. Untilled pastures generally run in the low to mid 50's. Fields where row crops have been planted for generations can run much higher. Up near 70. Sometimes the only thing separating these areas is a fence. The effects of mineralizaion shows up in the condition of the coins I find. Silver almost always comes out looking brand new. Always bright and shiny no matter where I find it. Apparently the metallic compostion of silver is more tolerant of the mineralization around here. From what I read, you can't say that about silver found on the beach, can you? The old Indian cents I find in "non-fertilized" areas (timbers and old farmsteads) have a beautiful green patina. The Indian cents I find in areas exposed to farm chemicals are usually very corroded. All the old shield nickels and V nickels I find are corroded and "rusty" looking. The buffalo nickels look orange colored and are not corroded. <img src="/metal/html/confused.gif" border=0 width=15 height=22 alt=":?"> Again, must be the reaction of the soil on that particular metal content. There is a lot of interesting information online about mineralization. Look it up on google and you can find tests ran by various detector manufactures as to how mineralization affects the operation of specific machines. As to the nail in the side of the hole, I found the same thing with old square nails. In fact,in one yard I did it several times before I started digging wider holes, just in case. It always was. Based on the sound, I would have sworn it was a coin. Maybe it has something to do with the refraction of the signal on the outer plane of the DD coil? Thought I was running a 1266 for a bit! <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol"> Haven't had the pleasure of digging the coppers mixed with trash. But, I may have passed by them and didn't know it! I got to slow down my sweeps!!!! HH

 

[Anonymous]

.... referring to ANY naturally-occurring soil component that is, to some degree, electrically conductive, and thus affects the send and receive signals from the searchcoil. Various iron compounds (magnetite, maghemite, limonite, etc) are major "minerals," but so are various forms of conductive salts, chemical compounds (natural or man-made, as in the form of fertilizers) various stone materials (and the finely decomosed dirt from those stones). Even plain old water, in the form of soil moisture, is a "mineral," inasmuch as it "activates" many chemical compounds to be conductive. THUS, yes, there ARE MANY different forms of mineralization. That is why a soil reading of "80" in one place may be "different" then a soil reading of "80" in another spot. Here in the Mojave Desert, we have two primary forms of soil mineralization, magnetite, also known as "black sand," and which is magnetic, and various forms of salts, collectively referred to as "alkali." These are radically different, even "opposing," in their effect on the searchcoil. When our soil is dry, the magnetite affects the detector, and the alkali is benign. But, when the soil is wet, the alkali becomes the dominant form of mineralization. As regards signals from iron objects on teh edge of the coil: yes, that can happen. The detector senses metal, but does not get a good enough "look" at it to ID it, and reject it, as iron. So, a :good" signal sometimes occurs. To better ID any target requires the coil to pass right over it. HH Jim

 

[Anonymous]

Thanks fellas,
And I had drug a large speaker magnet across the ground in one area and it got full of the tiny pieces of metal every time I did. Kinda weird how different things afeect these machines. Yeah Digger I know what ya mean about the "F" brand detectors, I got a beep one day while using the 1225X and dug and dug, got ticked off came back home and got the post hole diggers and dug a hole 2 foot deep, about 2 inches from the hole was a big rusty nail. <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol"> I used to complain about that model because it only had one tone ID and you had to dig everything. However it would get deep, real deep for a 200 dollar machine but it was found of iron. But since I sold it and spent 3 times as much on a more high tech. detector I have come to learn the only way to know for sure is to dig. The target ID is only and indication of what may or may not be in the ground, iron makes it sound somewhat nervous, and a positive ID on a dime could be a beer can a foot deep, But I enjoy treasure hunting and guess no one will ever have all the answers but still say the perfect machine should be able to tell you the difference in a tab or nickel, ring or pencil eraser and definately the difference in a dime and a beer can <img src="/metal/html/grin.gif" border=0 width=15 height=15 alt=":grin">
Hope all are well, Ray