Coal cinder yards

[Mark-VA]

I have a few locations where in years past they dumped the coal waste out in the school yards to get rid of it. These areas, I believe are the worst to hunt with a metal detector. I've sent samples to different detector manufacturers and non have gave a possible solution that I can presently perform. This material ranges in size from half a BB size up to a dime and easily attracts to a magnet. You can bury a coin at 4" deep and no detector can detect it above iron. Most of these areas have been home to baseball teams for more than 75 years. This leads me to believe there are many goodies to be found, but likely they are more than 4" deep. Over the last 8 years there has been 15+ different detectors used by many users in these areas and non (V3i, Etrac, DFX, Explorer SE etc) have been able to handle the ground. Now on with the next part of this post. Many studies have shown this material causes the high conductors to read as iron (common term wrap around effect). That being said, this is a possible solution, or at least one I can do.
On the DFX the DC Phase measures -95.5, -95.7, one place measured a bit better at -94.8. That's the ground range I'm canceling on the Whites units. Ground balancing to that range means I'm severely reducing target responses that fall at or close to that range. The V3 uses the same method and suffers from the same issues. You can activate the wrap feature, but the area I'd be accepting is the same area I'm ground cancelling at. Another solution might be to accept the lower negative ranges with all the upper positive ranges and assign a high tone including the iron range and the upper positive numbers and dig it all.

[Mark-VA]

I was kind of expecting someone to chime in on this question since there are so many White's users here.

[Ferric Toes]

I was kind of expecting someone to chime in on this question since there are so many White's users here.

I wonder if anyone has tried a PI detector with GB on this type of ground. Whites TDI would be a good candidate. I recently designed an industrial PI to locate metal in blast furnace slag which must be at least as bad, if not worse. Coal ash and coke should not be detectable with a PI working at 10uS delay but iron oxides will be. However, the GB should take care of that.

Eric.

[Mark-VA]

To the best of my knowledge there has been over 15 different machines in this area and not one was a PI machine. The only bad thing is no one around here is willing to purchase one. As a final note, these fields have been in use for many years and not one old coin has been found. We have yet to be able to detect a coin buried at 4" deep. I've buried a few coins in different places around the field and unless I knew where they were I couldn't detect them with any of the 15 machines we've tried.

[Ferric Toes]

To the best of my knowledge there has been over 15 different machines in this area and not one was a PI machine. The only bad thing is no one around here is willing to purchase one. As a final note, these fields have been in use for many years and not one old coin has been found. We have yet to be able to detect a coin buried at 4" deep. I've buried a few coins in different places around the field and unless I knew where they were I couldn't detect them with any of the 15 machines we've tried.

If I were you I would definitely try a TDI (beg, borrow, or hire). Sounds like you have virgin territory to hunt.

Eric.

[Mark-VA]

I do agree, maybe some day. I've offered an open invitation to many hunters that either have or have access to a PI machine (not anyone within 500 miles though) but no takers yet. I'd like one of the companies with a proto type PI machine to test their machine here. Maybe in the future. Thanks

[Ferric Toes]

I do agree, maybe some day. I've offered an open invitation to many hunters that either have or have access to a PI machine (not anyone within 500 miles though) but no takers yet. I'd like one of the companies with a proto type PI machine to test their machine here. Maybe in the future. Thanks

Hi Mark,
Are you anywhere near Red Hill? I have some soil here which I believe comes from a school yard and it is the one of the most strongly mineralised soils from the US that I have tested. Still nowhere near that from The Golden Triangle area of Australia though. The TDI works well in Oz so I reckon it ought to handle anything VA has to offer.

Eric.

[Mark-VA]

Not far from Blacksburg Virginia

[Mark-VA]

Thought I'd give an update of the coal cinder properties. Since the last post two more machines have been used at the locations and no noticeable results. The Minelab CTX and XP Deus. One of my hunting buddies uses the CTX and to be honest we both were hoping the machine would open up this land to something. The CTX, running auto sensitivity will throttle down to 3 or 4, that is about what the Etrac. I did have an opportunity to try the Deus and it would run what seemed to be ok, but could not or find anything below 4" deep.
Last year I found a location where the ground was fairly clean and buried a dime, penny and nickel. Waited 1 year and can't get a peep from any of the coins but the 4" PENNY. I can say I'm disappointed with my findings.
Now on the up side, thanks to youtube it looks like the Whites TDI is about the only way that seems affordable.
Hope Carl develops a PI machine for 1st Texas, then I might have a chance to test.
Mark Gillespie