Placer Claim Mined Out?

desertgolddigger

Bronze Member
May 31, 2015
1,098
2,096
Twentynine Palms, California
Detector(s) used
Bounty Hunter Time Ranger
Primary Interest:
Prospecting
I belong to a local club that owns a claim. This club has had this claim for many years, and acquired it after the old timers had mined it previously, and others after they commercial outfits closed up.
I walked quite a bit of the 160 acre claim, and noted that just about every wash had been worked. Most of the surface nuggets has also been detected by those with gold detectors. In other words, this place has been picked over and over and over.
But I m a stubborn type of person, and I figured, just watching how people ram their puffer and blower drywashers, that some gold was just being blown through them. maybe not much, but some small stuff that never got a chance to settle behind the riffles.
I know many of you would never go to the effort of digging for three to four hours through the tailings in these washes. Again, I'm a bit stubborn, and anyway, I just wanted to have some fun locally, instead of driving 300 miles roundtrip to something that gives a little more for less effort.
I've spent the last three weeks, digging a few times a week along about 30 yards of wash, and have recovered just about a gram of gold. That might not seem like much, but I have only dug up 5 grams, not counting this one gram in almost 20 years out here drywashing in the desert of southern California.
As you would know, things always seem to go wrong. My gas powered blower motor decided it was time for the repair shop, and haven't heard from the shop in two weeks. So I purchased a WORX WG521 corded electric leaf blower to use with my Royal Large drywasher. I'm using a portable generator to provide the power. And it actually is working better than with my old gas powered blower. I have to run the blower on the lowest speed, or I just blow everything through the riffles. Results are very good, as I am getting gold specks so small that I will have to use the Blue bowl in order to recover them.
I'm not only getting a little gold, I'm having some fun, and I am getting a good workout. I've lost 10 pounds since I started. So things are going well.
I'm still digging test holes around the old time hard rock mines in the hope I will find where the gold has drifted downhill below these mines. So far just a couple specks here and there. I figure I just have to move laterally one way or the other before I get something better Of course, I' don't really know if the old timers stripped the hillsides. Even if they have, they apparently aren't as thorough as I am. I hope that I may be lucky and find a larger piece of gold that the old timers, previous placer miners, and detectorists have missed.
Hope everyone is having as much fun as I have been having.
 

Upvote 50
Here are two links to decent 12v motors....One large (9 amps), and one small (< 1 amp). Small first:
https://www.surpluscenter.com/Brand...rowhead-SAB0189-Arrowhead-SAB0189-10-3107.axd
Large here:https://www.surpluscenter.com/Elect...rowhead-SAB0191-Arrowhead-SAB0191-10-3108.axd.
The big one is capable of running a 40" table, depending on how heavily the tables is built. I'm running that on my 42" x 10" dry sluice, and it has way more power than needed for that. The small motor runs at 925 rpm unloaded, and the large one at 1,000 rpm. Both are 12v, though I'm currently running the small one at 24v with a PWM speed controller. I designed my pulley's wrong and don't have time to make new ones before we head out. So to get the speed I need on the backpack dry sluice I went with 24v and the speed control.
Jim
Thanks so very much Jim. I have that first motor bookmarked. Your link to the speed controller did the same as when I tried to do links. I just need to find a speed controller with double the amp rating of the motor to be safe, and then get the same for a transformer 120vac to 12vdc.
 

Thanks so very much Jim. I have that first motor bookmarked. Your link to the speed controller did the same as when I tried to do links. I just need to find a speed controller with double the amp rating of the motor to be safe, and then get the same for a transformer 120vac to 12vdc.
If you know what speed you want you could skip the controller for the given voltage used.
 

I didn't go to the Claim today. I stayed home, and ran all my piles of dry washer material. I ended up with 52 half buckets, so it took a couple hours to get it all done, and do the cleanup of the backyard.

I got another surprise when panning the 1/4 to 1/8 inch micro pea gravel. I found another little picker weighing just 6/100 gram. The remaining material netted me .295 grams, which brought my August total to just over one gram.

I don't expect to reach my 2 gram monthly goal, unless I hit some really rich spots. I'm happy because the weather has not been friendly to my type of mining.
Keep at it it's adding up for you! Good luck and hope you find some pickers!
 

Keep at it it's adding up for you! Good luck and hope you find some pickers!
Good point about the pickers will help pay for this tool.
There could be some State mineral reports on the area that will help you to pinpoint the pickers.
 

Been out to the Claim a couple more times. One reason is that while I'm not getting a lot of the tiny gold, I'm getting more chunkier pieces. I got two pickers, .046 and .091 grams today.

I've finally gotten back to the main wash, and all these chunkier pieces are coming from that area along the very edge.

One thing I noted is that there's patches of cemented gravel filling low spots. I'm breaking up all of this, and scraping things down to solid bedrock. I'm also running into crumbling bedrock, so I'm trying to demolish these areas, until it turns into smooth bedrock. Not sure my efforts are paying off, but I'd like to think the previous prospectors who ignored these two areas, have provided me with some nice gold.

Any comments on my guesses about where the gold is coming from? I'm still learning where the yellow stuff hides.
Congratulations on your pickers! That makes it exciting for you! Good luck!
 

If you know what speed you want you could skip the controller for the given voltage used.
No, that's a bad idea. The Pulse Width Modulated controller controls the speed, but not by varying the voltage. if you reduce the voltage, the motor will overheat. The PWM'er controls the speed, by using varying pulses (widths) of the correct voltage. If you turn a PWM all the way down, it will still show the input voltage on a voltmeter, but the motor won't turn.
Jim
 

No, that's a bad idea. The Pulse Width Modulated controller controls the speed, but not by varying the voltage. if you reduce the voltage, the motor will overheat. The PWM'er controls the speed, by using varying pulses (widths) of the correct voltage. If you turn a PWM all the way down, it will still show the input voltage on a voltmeter, but the motor won't turn.
Jim
The idea here is if the speed that is decided on is known first use full voltage for that speed by passing the controller unit.

There could be some reduction of the volts if the motor is over sized and can take the extra heat.
 

The idea here is if the speed that is decided on is known first use full voltage for that speed by passing the controller unit.

There could be some reduction of the volts if the motor is over sized and can take the extra heat.
So why put the motor through that?? And why have a set speed when a controller will allow adjustment of the speed?
Jim
 

So why put the motor through that?? And why have a set speed when a controller will allow adjustment of the speed?
Jim
More efficient and less costs.

Will be more simple with less break downs comes to mind.
Get the motor with the gearing you decide on first (2-5 SPS is a very common speed range) Get a over sized motor and you will see a lot less heat and breakdowns. Some people will add a cooler for the heat on the gearbox.

The unit linked has a heavy duty fin cooled gearbox.
 

Last edited:
If done my way, you don't need a gearbox, so no cooler needed....and it's cheap.
Jim
 

If done my way, you don't need a gearbox, so no cooler needed....and it's cheap.
Jim
I agree figure what speed you want first.
The cooler for a gear box is not needed if it is oversized. The gearbox is for a much lower speed then 1,000 RPM's/
 

Here's a pdf of our Holman Wilfley shaker table. Maybe it will help you figure out what you need. If you want to see it in action, my mining partner will be coming from San Diego next week and we will have a lot of material to run by friday the 3rd. If you want to come over and bring your buckets Caley, your more than welcome and we have guest rooms as well.
 

Screenshot_20240124_190318_Samsung Notes.jpg
 

SHIPPING INFORMATION 8000 1600kgs (DD 3500Kgs)

https://www.holmanwilfley.co.uk/products/

Units ship in 20ft Containers

DECK DIMENSIONS Nominal 7.5m

2 Deck area

Conc Edge 1600mm, Tail Edge 4900mm

270Kgs

FOOTPRINT

~6m x 2.5m (not inc operator access)

ELECTRICAL/MOTOR DETAILS (x2 for DD)

3 phase, 380/415 volt, 50Hz

1.5 kW, IP56 Motor (x2 for DD)

WATER SUPPLY (x2 for DD)

Wash Water requirement of 20 to 35l/min

Feed dilution to ~25-30% w/w solids

SOLIDS THROUGHPUT RATE (x2 for DD)

Up to 2500Kgs/hour 8000SD (particle size

dependent)

2000: SHIPPING INFORMATION

Equipment Dimensions 3386mm Long x

1771mm Wide x 1455mm High

1020kgs

DECK DIMENSIONS

Nominal 2.1m

2 Deck area

Conc Edge 887mm, Tail Edge 2445mm

95 Kgs

ELECTRICAL SUPPLY

3 phase, 380/415V 50Hz

1.5kW, IP56 Motor

WATER SUPPLY

Wash Water requirement of 5 to 20l/min

Feed dilution to ~25-30% w/w solids

SOLIDS THROUGHPUT RATE

Up to 450Kgs/hour (particle size

dependent)

3000SHIPPING INFORMATION

Equipment Dimensions 3600mm Long x

1300mm Wide x 1330mm High

1220 Kgs

DECK DIMENSIONS

Nominal 3.0m2

deck area

Conc Edge 1030mm, Tail Edge 2515mm

180 Kgs

ELECTRICAL SUPPLY

3 phase, 380/415V 50Hz

1.5kW, IP56 Motor

WATER SUPPLY

Wash Water requirement of 10 to 25l/min

Feed dilution to ~25-30% w/w solids

SOLIDS THROUGHPUT RATE

Up to 850Kgs/hour (particle size

dependent)

Wilfley Unit

Unit is driven by robust Wilfley head motion with stroke adjustment options of : 8mm - 18mm or 18mm - 36mm.

Head motion is self- lubricating. Simple, robust design requiring minimal maintenance.

Deck is supported on 2x flexing spring packs and is vibrated longitudinally along the entire length.

Decks are made from good quality timber with standard 5mm rubber covers for maximum durability (White/Black Option).

A range of riffle patterns available to suit the application metallurgical performance.

Table tilt can be easily adjusted using a hand wheel, even while the machine is in operation.

Choice of concrete plinth or steel base mountings.

All feed/product launders polyurethane lined.

All Steels Galvanised (BS EN1461).

Fitted 2.2kW IP56 motor.
 

I rebuilt an orginal Wilfley Lab Table 2 winters back, Reed. I have great respect for his engineering genius. Of course that Holman table is far superior, especially in the available materials we have now. But Wilfley's stuff all worked really well for his era.
Jim
 

I agree figure what speed you want first.
The cooler for a gear box is not needed if it is oversized. The gearbox is for a much lower speed then 1,000 RPM's/
There is no set speed. Every different material requires different speeds, different slopes, etc. For fine gold, you need a short stroke and speeds approaching 400 CPM. For coarse material the stroke needs to be as much as 3/4", with speeds around 200. Caley can't afford to buy a vary-speed pulley setup like I have on mine, and doesn't have the tools to make them. So the only alternative is to use a DC motor with PWM controller.

Jim
 

There is no set speed. Every different material requires different speeds, different slopes, etc. For fine gold, you need a short stroke and speeds approaching 400 CPM. For coarse material the stroke needs to be as much as 3/4", with speeds around 200. Caley can't afford to buy a vary-speed pulley setup like I have on mine, and doesn't have the tools to make them. So the only alternative is to use a DC motor with PWM controller.

Jim
It may be easier for most to play more with the different slopes.
Just trying to keep it as simple as possible and that's why the single speed.
I was thinking of 3/4" to around 1" for the stroke for some materials.

Anyone play with 2"-3" stroke?
 

It may be easier for most to play more with the different slopes.
Just trying to keep it as simple as possible and that's why the single speed.
I was thinking of 3/4" to around 1" for the stroke for some materials.

Anyone play with 2"-3" stroke?
The reason Wilfley, on all his tables, built in adjustments that could be changed "on-the-fly", including speed, was he recognized the need for that, for each individual mine, and the ore each was processing. It's a time-consuming process to set up a table and get the most out of it.
Jim
 

Ours is an older model Jim, but the manual hasn't changed. We bought it new in 2006, then all hell broke loose in California with multiple mining partners deaths, divorces, cancer, county land closures, etc... so it's been sitting until last year when we gave up on the left coast & set up shop again here in Arizona.
Hopefully I can get a video up in a couple of weeks on it.
 

The reason Wilfley, on all his tables, built in adjustments that could be changed "on-the-fly", including speed, was he recognized the need for that, for each individual mine, and the ore each was processing. It's a time-consuming process to set up a table and get the most out of it.
Jim
Anyone use duel motion frequency?
Anyone play with a fluid air bed?
 

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