Metal Detector

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Bryan1
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Metal Detector

Post by Bryan1 » Sat Sep 05, 2020 9:06 pm

G'day Guy's,
A few months SWMBO said she saw some metal detectors that didn't cost the earth at the local tackle shop come supermarket and said I'll get one for your birthday. Anyway I had problems early morning starting my trusty '95 Hilux as it does look like the glow plugs are on the blink, so she suggested we buy one of those 12 volt 1000 amp gizmos the battery store sells. She said at that price it's your birthday present and when we tried it noway would it kick the engine over.

So I decided to buy a new starter motor and put that in and that was the problem all along, looking thru the exercise book the last and first owner kept and supplied me when I bought the ute the starter motor was original so after 400K time for a new one.

I went into my local bank so see about an incoming credit that wasn't showing and while I was there I asked about afterpay and what the bank thought about it. The reply was yes we support it fully and when the payments are due we pay them promptly.

So off I went to the tackle store to get my Fathersday present and that morning I did do some research and found the 44 and 66 models were the same detector but the 66 had the better software app. Now who in their sane mind would publish where you buzzed and found gold as every man and his dog would be there before you know it. :roll: In the store they one left and that was the go find 66 Minelab detector so I it bought using afterpay.

With a few beers under my belt I went and scanned my front paddock and came across some metal where the detector was making a very deep tone meaning it's more than likely a nail :evil: found some very rusty metal that cracked in my hand so I knew it was very old. The detector kept with the deep tone so kept digging and came across what looks like a cast iron butterfly valve. A round disk with a rod at the base and a rod ontop with a round dimpled end. After wirie brushing it was clear the hole didn't go thru and now I have it soaking in rust converter to see how it will come up.

I buzzed rocks I had got a few months back and sure enough the detector buzzed in a high pitch tone and then came a gig song meaning you had hit the jackpot. I used the detector on every pan before and after panning and after 6 pans I could see gold powder in the bottom of the beaker. It's going to take a heap more rocks and fine gold before I make some aqua regia which is only hydrochloric acid and nitric acid. Now on research adding the nitric acid which is a 4:1 ratio adding the 4:1 before you start when the gold mix reacts a heap of nitrogen dioxide which is a light brown gas and deadly forms. But by adding the nitric acid very slowly and given time little gas is produced.

They do say 5 grams a tonne make a viable gold mine and from what I've found quartz rocks that have ironstone and other stone always seem to have a small trace of gold. A couple of years ago I decided to design and make a 6" jaw crusher and got enough fine gold to make a small 3mm diameter ball of gold after smelting in my coffee can furnace using my mapp gas torch. As I had only used straight plaster of paris after the first run it was ruined but everything is a learning curve so with the next coffee can I'll mix some brickies sand with it so it can last a few runs.

Got a 85 acre farm in gold country to scan and the ravine across the road which goes for close to 3 kilometres. I'll bet this fram has already been scanned in the past but with many quartz belts a bit of hard work and crushing will get me to a point it's worth doing the acid run.

All good fun to be had and as SWMBO said well you found a new hobby and thats good, I replied well with first 2 ounces I'm buying an excavator then the fight started :sarcasm: :sarcasm: :sarcasm:

Cheers Bryan

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Yummyrum
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Re: Metal Detector

Post by Yummyrum » Sat Sep 05, 2020 11:04 pm

Sounds like a whole lotta fun Bryan .
I was bought up in gold country and I remember all those old Quartz stamping batteries . Believe they used to run the crushed Quartz and presumably gold over long copper plates that had Mercury on them . Mercury would hang onto the copper plates and attract the gold . Quartz dust would just wash on past to waste heap .
Every so often they would scrap off the Gold laden Mercury and run it through a retort . Basically a still . Mercury would boil off and be condensed and reclaimed leaving the gold in the retort .

Bryan1
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Re: Metal Detector

Post by Bryan1 » Sat Sep 05, 2020 11:13 pm

Yummy not a lot of mercury around here but the nitric acid I'll distil out of drain cleaner and the other acid I'll just buy, the precipitate is sodium bisulfate and that is a pool chemical easily bought cheap.

Yea this is a heap of fun and learning a bit of chemistry is a bonus and oneday I'l a vacuum distil of some of my goodies just for fun. now my vacuum pump is an old fridge compressor where one side blows and the other side sucks, I do reckon when the motor in the compressor loads up I'll have a full vacuum too.

Cheers Bryan

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Truckinbutch
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Re: Metal Detector

Post by Truckinbutch » Sat Sep 05, 2020 11:21 pm

I found the most profit from my detector came from scanning homeless camps alongside truck stops when I was laid over for a weekend .
While they were panhandling street corners during the day I detected where they slept at night .
Found enough lost change to keep me in food and beer most weekends .
If you ain't the lead dog in the team , the scenery never changes . Ga Flatwoods made my avatar and I want to thank him for that .
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Bryan1
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Re: Metal Detector

Post by Bryan1 » Sat Sep 05, 2020 11:47 pm

Yea here in the Adelaide hills it is gold country and will be a good day out with my family to the watering hole close to an old gold mine. i'm sure oneday I'll find a nugget where it changes my life.

Cheers Bryan

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Re: Metal Detector

Post by OtisT » Sun Sep 06, 2020 12:13 am

Sounds like you are having fun. I have a LOT of experience using metal detectors searching for gold. My father sold Metal detectors in gold country in the 70s, 80s, and 90s. I grew up using them and teaching miners how to use them. It was me and my brother’s job to teach folks who bought detectors how to use them. Usually after teaching a miner, we got to work some of their refined tailings. Lots of color. Lots of fun.

A metal detector will not pick up small flour gold. Only nuggets of a significant size. The further away from the coil, the bigger it needs to be to be detected. I doubt what you are detecting in a piece of quartz is gold unless it’s a significant amount, and if you have that much gold in a piece of quartz you sure don’t want to crush it to powder. Gold visible in quarts is more valuable for jewelry and such that the value of the gold by weight..

The most common way to find fine gold with a detector is by finding the black sand that collects with it. Gold being the heaviest material will deposit itself in crevices of bedrock or behind large tree roots or boulders in a river bed, like the earth is a big sluce box. Black sand is typically the second heaviest material around and will also collect with the gold, and it is something your detector will find much easier. Black sand has a different effect on a detector than gold. While gold makes a detector go beep, black sand makes it go quiet. If you tune your detector with a low consistent hum/buzz and pass the coil over a pocket of black sand the sound will go away (stops humming). When you find those null spots that make the detector go quiet, dig down to bedrock, scoop the material out of that crevice, and process that material. That is where your flower gold will be and if you are lucky some placer nuggets as well.

Otis
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Bushman
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Re: Metal Detector

Post by Bushman » Sun Sep 06, 2020 5:55 am

I have been an amateur metal detector for years. I have found a lot a war coins below a tavern on piers in my area on a minus tide. Also researching old mines and ghost towns in my state has been a lot of fun. As a boater I am always looking for different things to do and decided to purchase a magnetic fishing kit. Much cheaper than a metal detector and this fall when most of the fair weather boaters are gone I will walk along the docks and see what I can find. Just a hobby but fun things to do.

Bryan1
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Re: Metal Detector

Post by Bryan1 » Thu Sep 17, 2020 10:00 pm

Well with no work got another long weekend so this morning went out to the back of the farm with my detector, first scanned the ravine and it didn't take long for the detector to go nuts on a spot. So started digging and saw a small glint in the trowel, on cleaning up a small nugget that only weighs 2 grams on my scales. Went over a whole area and the detector was going with small hints so when the signal was greater started digging and sure enough found a small lump of quartz. Buzzing over it said it had something so in the back of the ute it went and off I travelled. Several other sites were worth digging so I grabbed more rocks and after I dug em up a quick buzz with the detector made a quick decision where the rock goes into the wall or gets crushed.

Ended up grabbing quite a few rocks so headed back and setup my 6" jaw crusher and thought well got 3 buckets that buzz and already been thru one crush cycle so may aswell put them thru again a few times to see how the crusher performs. Well it worked well and I put the rocks thru 3 times and got them smaller. Now when I tried with bigger rocks the crusher didn't want to crush them and at one stage it stalled the crusher.

So yeas although I used bisalloy 500 for both jaws and I just welded some pads going sideways thinking they would grip the rocks and crush them, well that is a big fail. So the crusher is going to be stripped again and using TC16 welding rods I'll weld up the jaws to it has corrugations just like the big jaw crushers.

So the next project is finally setup my 16hp listeroid which has a 5Kw genhead which I got for free as the guys said it didn't work. A quick job of taking out the brush's and flashing a 12 volt battery across the rotor solved the problem. Now when I ran it just charging the shed battery isn't enough load for the engine and in winter the 3hp aircon isn't an option but man I do miss the squeel the genhead made when I turned on the cooling. It acted like a brake but my listeroid just said thats nothing give me a bit of work. So welding up the jaws will be a full days work and close to 4 kg's of rod's will be burnt and the best part my shed battery will be fully charged. I can use my Lincoln arc welder off my inverter but after welding for 6 hours to weld up the new ovens for this 150 year old wood stove sure gave the shed battery a nice hit.

Now I've made the jaw crusher and I will get it working properly I do need a secondary crusher and I am thinking of making a hammer mill as I have a heap of old hammers off a crusher we repair at work every year. To power it I'll just fabricate and machine up a flat belt pulley and use my listeroid to power it.

Less than 4 years now until retirement as my super will mature when I'm 60 and by then both girls will grown up so no more school fees etc.

But eh with 85 acres a man has to make his own fun and with buying the detector it's only the first part of the equation.

Cheers Bryan

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MartinCash
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Re: Metal Detector

Post by MartinCash » Thu Sep 17, 2020 10:25 pm

Show us a picture!

Here's some I found a little while ago here in Tassie. If you read this tubbsy, these come from near your neck of the woods :wink:
small_gold.jpg

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tubbsy
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Re: Metal Detector

Post by tubbsy » Thu Sep 17, 2020 10:39 pm

MartinCash wrote:Show us a picture!

Here's some I found a little while ago here in Tassie. If you read this tubbsy, these come from near your neck of the woods :wink:
small_gold.jpg
Wow, there is some decent stuff there then! I might have to take to Dad's detector out one weekend.

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Truckinbutch
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Re: Metal Detector

Post by Truckinbutch » Sat Sep 19, 2020 6:11 pm

The beep you don't dig is the treasure you passed by .
If you ain't the lead dog in the team , the scenery never changes . Ga Flatwoods made my avatar and I want to thank him for that .
Don't drink water , fish fornicate in it .

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Bushman
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Re: Metal Detector

Post by Bushman » Sun Sep 20, 2020 5:11 am

Truckinbutch wrote:
Sat Sep 19, 2020 6:11 pm
The beep you don't dig is the treasure you passed by .
+1, I have multiple setting and have it set for the lowest setting. I find a lot of bottle caps but also where I find the jewelry and rings. Ocean beaches are also some of the easiest as the digging in the sand is much easier.

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