Hunting In Coal Waste

[Mark Gillespie]

A few things I've learned about coal waste hunting.

 

I started inquiring about some old locations I hunt.  Most of the locations are old, shut down schools where coal was used as a heating source for decades.  Before the EPA was birthed most people did what ever pleased them when it came to disposing of waste, regardless of what it was and these old school sites are no exception. The burnt coal waste was spread over many acres of school property which created some extremely harsh ground conditions.  Grass and weeds find it hard to get a start and most areas are void of any vegetation. Most of the school grounds look like Martian landscapes with small BB size or smaller pieces of coal waste everywhere. This material attracts to a magnet with little effort and can reduce depth of all VLF detectors by well over half. In fact until recently maximum detection depth was actually 2-3”.  Any target deeper would give a solid iron audio report if any sound at all. After many years of hunting these areas, all but completely unsuccessfully, I finally purchase a White’s TDI SL. 

It turned out the SL opened up these old sites and many nice coins, relics and gold jewelry were unearthed, but not without many trials and numerous adjustments.  

Case in point: one particular area had been, in my opinion hunted out with many different VLF machines (ranging in cost from $250 - $2000) over a 10 year period and I was certain there were no good targets left.  

Now I’m going to fast forward 2 years of hunting experience and mention a couple very important and rewarding hunting trips that might help someone.  

Settings: sensitivity 6, ground balance 7 ½, pulse delay 10 and conductivity set to high and used the stock 12” dual field coil

First was an old school site where both coal waste and nails are very abundant.  I had been hunting about 15 minutes and all the SL was giving were very short audio reports, which sounded more like chatter or EMI and not targets.  This prompted me to increase the time delay to about 15 , which increases the time before a transmitted signal is analyzed, thinking the small pieces of coal waste were the short reports (partial masking) I was hearing. Continued hunting another 5 minutes and noticed the short audio chatter continued but not to the same magnitude. Stopping and increased the delay to around 17 and off I went hunting again.  Suddenly I noticed the machine was running very quiet, to quiet.  

A minute or two later and a very loud low tone, which on the SL means a high conductor, I stopped and reduced the delay to 10 and found my definite answer. The coal waste was causing the ground chatter and false audio reports.  Increased the delay back to 17 and recovered a wheat penny around 4” deep.  Now to be honest I had to stop for a moment and think about what just happened.  Decided to start over I returned to where I began hunting and discovered I had passed right over many good targets.  After digging a few more wheat pennies and a silver dime I decided to start checking these targets before digging and discovered if I decreased the delay most of these targets became the short sounding audio reports I had heard earlier. The PI was just the trick to discovering some nice coins deeper than 4” in these barren areas.   From this site I learned the time delay helps with eliminating small metallic pieces from interfering with coins and other relics.  

I must admit, at times, I tend to over think some of my hunting trips but the thought came to mind. What if there was gold jewelry in the area where I was hunting coins (conductivity high)?   Yes I could have been hunting with a setting of all but the area is so polluted with targets I chose only high.

So another trip to the same site with only two setting changes pulse delay 15 and conductivity set to low.  In addition to this I change, I opted for the smaller 7 /12” dual field coil.  Again the delay settings helped with the coal waste problem mentioned above and allowed me to hunt with a little sanity. 

Less than 15 minutes later came my first ring, not gold but gold plated, but that helped motivate me to keep going.  Dug a couple beer pull tabs and finally a nice gold class ring came to light.  What a very rewarding hunt it turned out to be. 

Mark Gillespie 2017

[martygene]

Very nice going and super detective work. Great finds. thanks for sharing.

[johnedoe]

Great job on getting to the goods.....

[strick]

Awesome story. I have a TDI pro and hunt beaches with it occasionally....in  black sand infested areas. Do you think that increasing the pulse delay a little would help in this environment? Thanks for the post.

strick

[Mark Gillespie]

If you're having a lot of chatter from the black sand I'd raise it a little, but the coal waste I deal with is BB size and will attract to a magnet.  Raising the delay at my site allowed the signal from the waste to dissipate enough for the coins to be heard.  I'm still amazed at the TDI capabilities and also limitations. 

At the beach I try to run with ground balance off and delay of 10.  I have found if I bump the coil on the sand it will false.  I might add a sensitivity of 6 is enough and you'll still dig deep targets. 

 

 

[strick]

47 minutes ago, Mark Gillespie said:

If you're having a lot of chatter from the black sand I'd raise it a little, but the coal waste I deal with is BB size and will attract to a magnet.  Raising the delay at my site allowed the signal from the waste to dissipate enough for the coins to be heard.  I'm still amazed at the TDI capabilities and also limitations. 

At the beach I try to run with ground balance off and delay of 10.  I have found if I bump the coil on the sand it will false.  I might add a sensitivity of 6 is enough and you'll still dig deep targets. 

 

 

Thanks for the reply. I hunt the beach with the same settings as you but I'll try and play with some un dug targets next time and see what happens. The magnet in my scoop sometimes as an inch of black sand stuck to it lol

strick 

[GB_Amateur]

Only two Jeffies and both wartime (silver alloy)?  I like that ratio!

Thanks for the details -- I like seeing pretty pics, too, but I learn more when settings, etc. are reported along with the finds.  You said you first hunted high conductors only and then hunted low conductors only.  Do you ever hunt with no selection (so hear all) or is that noisier (signalwise, I mean, not sound volume)?

[Steve Herschbach]

Great thread Mark. Coin hunting with a PI is not for the faint of heart but for some locations they can work some real magic.

[Mark Gillespie]

8 hours ago, GB_Amateur said:

Only two Jeffies and both wartime (silver alloy)?  I like that ratio!

Thanks for the details -- I like seeing pretty pics, too, but I learn more when settings, etc. are reported along with the finds.  You said you first hunted high conductors only and then hunted low conductors only.  Do you ever hunt with no selection (so hear all) or is that noisier (signalwise, I mean, not sound volume)?

I've tried all, but there's just to much to listen to. 

[Swampstomper Al]

On 7/4/2017 at 7:28 PM, Mark Gillespie said:

A few things I've learned...

Nice..! Following along with GB_A's thoughts the silver is in most remarkable condition considering how long it's been buried.. Also, in case you haven't already done so I'd (re)check the '43 for the possibility of a 3/2 or a doubled die (for this item it will be a doubled eye..)

Swamp