I have worked hard to figure out this type of garbage when using my Vaq and Compadre.
Remember that these detectors don't really discriminate the same metal at all sizes the same way, it all has to do with conductivity and in this case the size of the targets matter.
A really small piece of foil might disc out in iron, sports drink inserts, condiment packages and gum wrappers on mine will disc out just a hair past the n in iron on my Vaq and C, larger or compressed and thicker foil like the kind you find around campsites and picnic pavilions will disc out higher.
A big chunk might be way high in nickel, zinc or even higher if big enough.
Even though all of these are foil, to the Compadre they are all completely different animals and will behave and disc out differently.
Same on can slaw.
I have also discovered that foil doesn't break down...ever!
I hunt some woods sites where there has been camping going on for over 100 years.
Tons of this stuff everywhere, it might be dirty, but most of it it is just as solid as the day it was made and that will never change.
Because there is so much of this stuff out there in all sizes this is what I came up with to try to figure these foil targets out so I can leave a lot of it in the ground with a petty high confidence level.
First, the really big stuff, large chunks of full sheets folded up like the kind you can find at campsites, can have a "tinny" component in the sound like I hear on large cans or big pieces of can slaw.
I can hear this annoying sound on my Vaq that has the high tone option very well, but it works on the Compadre most of the time too.
Smaller pieces don't sound quite the same and can fool you.
It took me awhile to learn the difference but eventually I did.
I say I am a dig it all hunter but I am not really...I dig enough trash as it is, solid sounding trash, if I can leave some in the ground and not be bothered worrying about passing over some great targets without the "what ifs" bothering me I am happy.
You never know till you dig it, of course, but if I do miss something from time to time I don't know about it and don't worry about it and I have found way more than my share of great things so I am happy with the way I do this.
I never thumb up to listen where the target discs out...I ALWAYS thumb past the fade out point and then back down and listen to how the targets come in.
Good targets like coins and rings will usually just come in this way, irregular shaped trash like can slaw and lots of that foil will click, chatter or break up a lot before they firm up.
I dug tons of trash in the past to make this one of my rules whether to dig or not and nowadays I usually don't if targets break up like this.
Not all foil will do this, and some shapes like my arch enemy those hated round sports drink inserts never do, neither will condiment packages and gum wrapper foil for the most part.
Even though I suspect what these are because of that knob position at just past iron, some really small gold rings, gold earrings and smaller chains could act the same so I still end up digging a bunch of these just to make sure.
I did make a video about these stupid things and figured out that by lifting the coil and keeping the coil at the right angle these things will break up at the fade out point a lot more than good targets will...mostly.
If I get a signal that comes in at that high iron level by turning the knob back, AND it breaks up a lot when lifting the coil at the right angle I am pretty sure it is one of those 3 target types.
Still dig these more often than not, however, because as I said, chains are just weird.
It is a war out there...us against the trash.
You either have to actually dig it all or figure out ways to put your mind at ease if you would rather not.
I have settled on a combination of both depending on the situation and my mind is at piece...so far.
One day that could change.
Here is that sports drink insert video.
[video]https://www.youtube.com/watch?v=mCRjmlO84nI&list=UUpjgKU3qrKYB57QV5wB3yog[/video]