Key to rusted bottle caps?

[Southwind]

Over the years I've used a lot of different detectors, all which had issues with rusted bottle caps, some worse than others, and the Deus likes them as well. Is there a good setting to help identify them? I used Iron Audio at 4 and it would grunt before & after the cap, but only if you used a long swing. If you try and isolate a target to get a better VDI the grunts go away and it reads as a good target. Rusted bottle caps are tough for any detector and anyone who claims different is just not being honest. I'm just looking for the best setting, if any, to help identify them.

Thanks

 

[HuntinDog]

What I've used is the "drag back method".
Once you find a "good" target swing in small sweeps back and forth as you drag the coil back off the target.
As the coil leaves the target you will hear the tone break up and grunt on the bottle caps.
It will stay solid and drop off sharply on good targets.
This method work most of the time for me..
Hope this works for you...

HH

 

[CZconnoisseur]

Recently I've been using 4 kHz almost exclusively for the fairgrounds and rental houses. Both types of sites are littered with caps, but most of the time they come in around 90-91 in 4 kHz. A silver half dollar will register anywhere from 87-90 depending on a few factors, but so far any 4 kHz program seems to ID caps better than any other frequency. Reactivity set at "3" makes 4 kHz searching very thorough and doesn't "draw out" the signal as much as lower reactivity settings IMO. If you notch out "94-99" this takes care of a LOT of caps - but there will be some that come through at 88-91 at times, but the audio is not the same as a similarly conducting non-ferrous target. Non-ferrous targets have a "round sound" or "extra harmonics" while scanning...to me it sounds like a "whisper" attached to the end of an audio signal and when I hear it - most of the time it's silver - don't know how else to describe it

But I dig my share of caps - probably at least one cap per keeper at the fairgrounds and I haven't found any hard and fast rules to totally eliminate them. Some caps sound great in one direction but are totally silent in another swing direction, and some caps don't hit at all while others hit in both directions and sound GREAT!!! I've learned to live with it but it would be nice if a software upgrade would remedy this...time will only tell!

 

[Portagee Kawika]

They're tricky, particularly the older ones.

Of course, from a site analysis point of view, caps are a useful tell. Are you digging deep caps? If so, the person who hit the place before you (if any) was either an absolute detecting god with an excellent machine who can cherry pick with the very best of them, couldn't hit that depth, or just plain missed some stuff. The odds are that it's one of the latter two, which is good news for you. Finding deep caps is almost as good as finding deep quarters or wheaties for me. It tells me that there's hope for the site.

If I'm on a site that's more than a few decades old and I'm not finding any deep caps, that tells me a lot about how the site has been worked in the past - namely, long and hard. If there's anything old left, it's masked, tricky, and/or the result of a gridding error or possibly changing topography. I know not to expect much.

Kind of the same deal with pull tabs and beaver tails, or even the ratio between zincolns and coppers. How folks have worked the site in the past will affect what I'm going to see today. It tells a story. Bottle caps are part of that. I still throw mine out at the end of the day, but I'm not that annoyed by them...at least, not for the first hour or so. It would be nice to have a reliable method for making them disappear.

 

[Leo234]

A lot of good suggestions here and I use them all at times. However, now that I have logged quite a few hours with the Deus I have noticed when I get one of those
iffy signals I simply raise the coil up and while sweeping I pay attention to the numbers. If the numbers drop significantly or change significantly it is a bottle cap nearly every time. If the numbers stay stable it is usually a keeper. I usually coin hunt in 12 khz just for the record. Try this simple technique and let us know what you think. I'm sure many others will chime in with their techniques as well. There is more than one way to skin a cat. Happy Hunting.

 

[samandnoah]

Folks have suggested several different approaches to the bottle cap issue. In some cases, you can hear the iron buzz, but sometimes they just sound great, and will even give a stable VDI. Or as you're pulling away, if your coil is also going over another target, you may not hear that break-up crackle clearly.

My favorite technique (as written, it assumes you're hunting in 8 or 12 kHz -- I usually use 12 kHz myself) is to flip over to a 4 kHz program. If the VDI goes UP, then it's a bottle cap. If it goes down, then it's not, and worth further exploration. This will not work if you have "ID Normalization" on -- then everything registers the same as it would in 18 kHz. I have a 4 kHz program set up btw my favorite 2 custom programs, so checking is a snap with 1 button push over to the program, quick check, and then 1 button push back. For example, in 12 kHz some bottle caps will ring up right at 87 or 88 and hold steady, like copper pennies and dimes do for me. When I flip over to 4 kHz, it'll ring up as anywhere from 94 - 98. Then I know it's a bottle cap. If it's close enough to the surface I usually will still pick them up to see if it's masking anything else, and that has worked out well for me on several occasions.

By the way, with all of the interest in hunting in 4K (including me recently!) obviously you can do the reverse, and flip over to a higher frequency program. If the VDI goes down when you flip to a higher frequency, then you know it's a bottle cap. This technique has been almost foolproof for me.

Good luck, and happy hunting.
Rich

 

[54shooter]

I've been using 4K as a check and it works great. I'm really new to the Deus and I still dig some targets even if the 4K check tells me not to. I still have a ways to go before I'm completely comfortable with it. I do have to say it hasn't failed me yet.

 

[Hauptmann aD]

I found that in the Dry Beach program bottle caps are almost eliminated (ground filter 4!), the crux is, you will also lose depth and eventually miss some other targets, including jewelry.
Bot for a quick coin hunting session ... why not. It's all a compromise.
Best greetings from Germany
Olaf

 

[Sleepyjim]

I got an idea on how to eliminate them all!
Have a friend or wife use a detector in all metal mode and tell them to dig all signals, go have a cold one while they "enjoy themselves"....

After a nice big section is "cleared" go to it......BAM! no caps or pulltabs.

Ok who wants to go out?

LOL


JIm

 

[Southwind]

Thanks for all the input. I set my Deus to use the switch from 12 KHZ to 4 KHZ and I'll try the "drag back method" as well.

 

[Big Boys Hobbies]

Make exact the program settings in another saved program with 4 KHZ as the frequency and you can hear the difference. Hitting the + or - button from the main screen will switch programs with 1 press.