The AT Pro's reaction to 40 lbs of Black Sand...

[bearkat4160]

I have 40lbs of black sands left over from dredging and I ran the AT Pro over it. It was about 3-4 inches thick and spread out over about 1 1/2 sq ft. and is about 90% black sand concentrations.The AT would not ground bal to it..it kept chattering as it was trying to balance over iron.

I detected it after grnd bal to the surrounding soil (91 of 100 bal). It made a sound and was around the 30-34 mark on i.d. So I grabbed some in my hand and spread it out about 1/2" thick and 6 sq inches. It made a slight chatter on it.
The less the black sand the less the signal till there was none with a decent amountof BS still there.

My conclusion in the test is the AT Pro would not be as good as an All Metal machine with a threshold for finding black sand deposits. Unless it is a MASSIVE amount in concentration, which will then appears as a iron signal. Could be done with some practice and skill.

The pinpoint function however worked quite well in detecting the black sand with a positive signal not a null or negitive signal, in short burst in pinpoint. With practice this also can be utilized to find black sands.

Old school all metal w threshold is still my preference for this.

Alan

 

[INCH]

That is very informative.I have seen your post before on this forum and seems u really try to open up the eyes of advanced detectorist, I found my deposits in the form of wheat pennys today . Keep it up , Im always learning , especially considering the type of dirt that others detect in.

 

[Jason in TN]

Did you true to put a coin in it and see if it would pick it up?

 

[bearkat4160]

Good idea...will do tommorrow1 Thanks..

Alan

 

[Uncle Willy]

Yeah that works best for black sand.

Bill

 

[Uncle Willy]

Did you lay a nugget in that sand to see if the AT could sniff it out?

Bill

 

[metalhead]

Thanks Alan!

 

[bearkat4160]

and the AT Pro detected them but the depth was hampered by the thick iron rich black sands. I got about 5 inches max on both targets. That black sand sure did mask the targets enough to cut its depth by an avaerage of 50%-60%.
The coins were in the Black Sand at about 2.5-3 inches deep. One at a time.

Alan

 

[Jason in TN]

Thanks did they actually read as a dime or was the I'd lower.

Jason

 

[bearkat4160]

Yes it still i'd as a dime and nickle...it bounce around more though in and around the proper i'd, so I just kept waving coil over target until the AT figured it out a bit more. Give her a little time to analyze.

Alan

 

[davemill]

Today we hunted Fort Funston beach in San Francisco. Some of the worst black sand we've ever encountered. Here's a video of the black sand:

http://www.youtube.com/watch?v=7WouQb1CGCI

Our new AT Pro cut right through it. We only had an hour, but we were able to find coins, bottlecaps, pull tabs, and small junk ferrous and non ferrous targets.

Our Garrett ProPointer failed miserably in this black sand. This is the first time this great pinpointer has failed us. Strangely, our old Whites Bullseye II did fine.

Please note that this was dry black sand. We did not try salt water black sand.