Constant iron sounds?

[Neugene]

I spent the day at a school house that was built about 125 years ago or so. Since then it has been used as a house by several different families who have left an unbelievable amount of trash in the yard. The upside of this is that I can now identify a screwcap absolutely.
The SE did a good job of separating a few good targets, but I ran into a few weird spots.
I hunted mostly in IM, All Metal using ferrous sounds. There were patches of ground where there was a constant and I mean constant, iron tone. It was not overloading, and it varied a little but there was a continuous iron drone.
I switched to the factory preset discas well as trying to raise the IM level by a couple of notches. This nulled the signal and made me worry that I was going to walk over a good target. I tried different sensitivity settings in manual as well as semi-auto.
Has anyone else ran into a similar situation? If so, how do you deal with it?

 

[alton]

I have ran into many very old homesites in this area that have become very iron infested, along with other non ferrous junk that can make it a night mare.

Basically, it is like cleaning every dish in your house. You start with one dish at a time. You break a mammouth project down into smaller more manageable projects that you can handle one at a time.

With a iron/trash site that I know has to contain good targets, I grid off a small section, usually 6'x 6' square of promising ground and I dig everything. I sweep east-west, north-south and diagonal. You should go to "all metal" to make sure you are getting everything including the iron. Then I analyze what I have found and if I was able to make a dent in the iron or not. Pay close attention to what was found at what depth.

For instance, if you get a wheat penny at 3 or 4 inches, you know silver can be at that depth and below. If you remove a piece of iron check again to see if it unmasked any good targets. Slow way down to give the detector enough time to separate targets next to each other.

If the first 6 foot square was good to you, then try another one next to it. If it wasn't try a different area.

I have a buddy that doesn't like to knock on doors. He leaves that up to me. Often I will try for an hour or so before I find someone home or someone willing to give us permission. He jumps out of the truck swings his coil in a triangle pattern around the yard and in 10-20 minutes if he hasn't found anything he wants to know if I'm ready to go.

Just because an area is old, doesn't mean you can cherry pick it as he tries to do. Check your plugs to see if the area you are in has been filled recently, or if it has "old dark dirt" that hasn't been disturbed before. In my case red clay near the surface is a dead give away that it has been filled.

So check the dirt and other areas that will still hold the old stuff. I worked a very old home once that had fill in most of it, but there was a high area near the road that was about a 10'x 20' strip that I found four .58 cal bullets and part of a US buckle that was broken off. The rest of the yard only gave up a few clad coins.

As Andy Griffith told Gomer one time about a blind date, "Don't over expect!". Just because the house is old, it does not automatically mean that it has that many old coins. More than likely, it has been detected several time before and all the easy coins are gone. Also most of the old coins are deep by now unless something was in the way to keeping them from going down.

The good part is that at least you are at a location that you are likely to find a good coin. But you may have to play this fish longer than normal. Patience is hard to apply to iron infested sites, but with current technology it is about the best weapon.

HH Alton

 

[Neugene]

Thanks for the info Alton.
I worked this site incredibly slowly for several hours. I will take your advice and section it off into smaller areas when I try it again.
It has never been hunted before that I know of. It is on private property and if the owner did not know my grandfather I would have never gotten permission.
One thing that I did not like was the fact that I dug a few screw caps and aluminum cans at about 6". This seems deep for this kind of thing if the area has not been filled. Do you agree? Most of the ground is dark for the first several inches then you hit the red clay.

 

[alton]

Yes, 6" on a can seems like a fast sink rate unless the can is early like 1962. Actually, buried cans always make me wonder why they are as deep as they are. The reason is it is one thing to toss a pull tab or bottle cap on the ground, but I notice most people don't just toss a can on the lawn. Usually they will attempt to bury it right then and there. I remember as a kid seeing guys kick a hole in the ground with the heel of their shoe and put the can in and then stomp dirt over it leaving it buried at the start a good 3 or 4 inches. So I don't usually put too much into how deep a can is.

The exception is that people used to burn their trash in trash cans in their yard. I'm not sure what to expect from that, but probably after the ash pile got so high they would haul it off. I remember seeing that done. Perhaps some of it was deep enough to miss the haul. In any event, if you are finding them all over the property they must have got there some other way.

Bottle caps can be quite old, although most tend to rust out much quicker than when the aluminum pull tab era began.

But that is a clue right there. The iron in the cap can hide or mask a good target. Masking it is not as problematic as hiding it. When iron is masking you can here the iron signal and dig it up. When it is hiding you just hear a null in the threshold. So, you may have to revert to digging up nulls in your 6' x 6' square just to ensure that nothing is bein hid by iron. The problem is that sometime all that is left of the iron cap is rust. This rust hides a good target and you dig to find the iron and don't find anything. Until we get technology that can see through this we will continue to be frustrated somewhat.

However, you may be pleasantly surprised to find good stuff there. Old coins may have been hidden from others all these years for the same reason they are hidden from you. Once you disturb the rust/iron matrix some of the good targets may pop through. The only way to know what to expect is to dig it up and see what happens.

To be certain, this will be a difficult site. Some of the better stuff may already be too deep for current technology. By digging everything in your test patch, you can make a decision how much time you want to spend on the rest of the site.

I hope this helps.

HH Alton

 

[Mirage]

I like Alton's methodology - very good advice. But something to keep in mind....Too high a sensitivity and you will not find targets that might even be a couple inches deep. If I get that constant nulling sound I switch to the 7.5" coil and lower my sensitivity. This is more for cherrypicking among iron. You could have a coin at 3 inches and big iron at 6-8 inches. Too much sensitivity and all you see is the iorn. I gotten "iffy" signals in iron infested areas. I turn down the sensitivity and the iffy signal now sounds very good. Dig and behold a coin.

Bob