Here in the high Arizona Desert Country water to use for sluicing is at a premium. Therefore, operating a wet sluice generally
requires hauling in water to run a "recirculating system". Recirculating Systems are pretty much unique to this
part of the country as most other parts of the country have an abundance of useable water available at the dig.
The pictures on this page show some of the Huachuca Prospectors Club members recirculating systems and the ingenuity involved
in putting together such systems.
Basically these systems consist of a sluice (DUH!), framework for holding the sluice, tubs for holding the water and some
sort of water pump, either electric or gas operated, to recirculate the water. Valves are generally used to control the amount
of water flowing over the riffles in the sluice.
Material is classified (usually to 1/2 inch or less), then poured into the sluice and allowed to wash through. Tailings
are caught at the bottom and disposed of. After running the material, the water flow is throttled down, a container is placed
at the bottom of the sluice and the concentrates that are in the sluice are washed into the container for further processing
(i.e.) panning. During this process, all the fine gold and nuggets and possibly even gem stones are recovered. In an area
where water is scarce or unavailable, "recirculating systems" are certainly a viable solution for recovering gold.
TIP: MAKE YOUR WATER WETTER....Add a small amount of "JET DRY" or liquid dish soap to the recirculating water
to help prevent fine gold from floating away.
DRYWASHING FOR GOLD
Drywashing is a dry process method for recovering gold. It is a mechanical method used to separate gold from dry dirt or gravel.
This method of gold recovery was first introduced to the prospecting community around the early 1920's. Today, drywashing
for gold is particularly popular in desert regions where water sources are scarce or non-existent.
TYPES OF DRYWASHERS
Two basic drywasher design concepts have been developed through the years. Although many varieties of drywashers exist,
most drywashers fall into one of the two following categories:
The bellows type drywasher;
and the vibrostatic, or blower type drywasher.
Bellows type drywashers are most commonly operated by hand (using a crank or lever) or are driven with an electric motor.
When using a battery operated electric motor, it's a good idea to place the battery in a plastic container so as to prevent
any possible accidental spillage from the battery to be contained and not introduced into the surrounding top-soil. A small
gel-cell wheel chair size battery placed into a ventilated small hinged lid cooler works great.
Vibrostatic drywashers are powered, almost exclusively, by a blower assembly attached to a gasoline engine.
BASIC ANATOMY OF A DRYWASHER
Before understanding how a drywasher works, one should become familiar with the basic anatomy of a drywasher. There are
four basic components to all drywashers:
the riffle tray;
a method for compressing or blowing air;
The top portion of a drywasher is known as a hopper. The hopper usually consists of a box covered with a wire mesh or
extruded metal screen. This screen is commonly referred to as a "grizzly".
THE RIFFLE TRAY:
The mid section of all drywashers consists of a riffle tray assembly. The riffle tray is a frame that houses a series
of riffles and often looks similar to a sluice box. The underneath side of the riffle tray consists of a piece of stretched
cloth or other porous material; allowing air to pass-through the bottom of the riffle tray.
A METHOD FOR COMPRESSING OR BLOWING AIR:
How the lower portion of a drywasher is designed can vary depending on the type of drywasher in question. On a bellows
type drywasher, the lower assembly usually consists of a bellow. The bellow can be operated manually (with a lever or hand
crank) or with the aid of an electric motor or gasoline engine. On a vibrostatic or blower type drywasher, the lower portion
of the machine usually consists of a box into which compressed air is forced. Typically, a blower assembly driven by a gasoline
engine is used as a source of compressed air for vibrostatic blower type drywashers.
On almost all drywashers, the hopper and riffle tray are supported by a free-standing frame.
HOW A DRYWASHER WORKS
Dry, gold-bearing material is fed onto the grizzly screen, usually with the aid of a shovel or bucket. The thinner material,
such as dirt and small gravel, falls through the grizzly screen and into the hopper. Larger material, such as rocks and sticks,
roll off the grizzly and back onto the ground.
Material from the hopper is then fed by gravity into the riffle tray, through an opening in the bottom of the hopper.
The rate of flow from the hopper to the riffle tray is usually regulated by an adjustable door or shutter on the bottom of
As the material flows across the riffles, air is blown through the bottom of the riffle tray. Lighter material is kept
in a state of suspension; riding on a cushion of air until the material eventually leaves the riffle tray. Heavier material
(such as gold) is not lifted by the air and gets trapped by the riffles.
Drywashing is one of the fastest methods for recovering gold from dry material.
Operating a drywasher can be a good form of physical exercise.
Drywashers can be "home-built" very economically; reducing initial capital investment while increasing the enjoyment
gained from gold prospecting.
Weather conditions such as wind or rain can greatly effect the operation of a drywasher.
Drywashers can be used effectively only if the ground is almost completely dry.
In some cases, drywashers can be "bulky" and difficult to transport.
Operating a drywasher can be a "dirty job"; as most drywashers generate a great deal of airborne dust and dirt
when in use.
Gasoline powered drywashers have a tendency to be very noisy.
As with most mechanical devices, drywashers require a certain amount of maintenance and are prone to frequent mechanical
MORE on DRYWASHING
Dry Washing is the use of a "Dry Washer" to separate gold from sand and gravels without the use of water.
A dry washer begins with a "Grizzly" onto which gravels are shoveled. The grizzly is usually a piece of expanded
metal mounted on an aluminum or wood tray. The grizzly is mounted at a fairly steep angle and above the dry washer's sluice
box. Anything larger than the holes in the grizzly falls or is scraped away and falls behind the dry washer. Anything smaller
than the holes in the grizzly falls onto the tray and into the top of the sluice box.
The dry washer's sluice box is designed similarly to that of a conventional sluice box that uses water with a few exceptions.
The riffles in the dry washer's sluice box are pointed up towards the top of the box, instead of towards the bottom of the
box. This allows gold to be trapped under the riffle. Holes drilled into the sluice box allow forced air to blow away anything
that is lighter than gold (and black sand). Therefore, the gold and black sand remain in the box, trapped behind the riffles,
and anything lighter is blown away.
The air is forced through the holes in the sluice box by one of two methods. The original way used by the old-timers,
and still used today, is a bellows mounted underneath the sluice box. The bellows is powered by a hand crank mounted on the
side of the dry washer, or a gas or electric motor using pulleys and belts. This is called a "puffer type dry washer."
The second way, which is more popular, is by means of a leaf blower (gas powered). The leaf blower blows air through a
flexible hose similar to home dryer hose, which is connected to the bottom of the sluice box. Inside the sluice box, a fan
is mounted that spins as air is blown into the box. Mounted on the fan is a weight that throws the fan off balance when spinning,
and vibrates the entire box. This additional vibration assists in forcing flour gold to the bottom to be trapped. The air
is blown up through holes drilled in the bottom plate of the sluice box. The holes are located directly behind the riffles.
The plate is covered with a fine mesh material that keeps "fines" from leaking through. The "heavies"
are trapped behind the riffle and the lighter material is blown off.
The grizzly and sluice box are mounted on a frame in such a way as to have the grizzly "feed" the top end of
the sluice box. The sluice box is mounted on the frame at an angle, with the top of the sluice box mounted solidly to the
frame, and the bottom end suspended by a small chain and springs to allow efficient vibration.
Dry washing requires that the sand and gravels being dry washed be powder dry. If necessary, shovel the material onto
a tarp to dry in the sun, then pour into the grizzly.
Dry washing is very efficient, but not quite as efficient as using a recirculating system or dredging. But, when water
is scarce or non-existent, dry washing is the method of choice.
Why Use A Gold Wheel?
How many of you have attended a gold show and watched with fascination as gravel is fed into a spiral gold wheel and the gold
appears along the spirals then disappears into the center hole and lands in a cup?
For those who process lots of black sand the choices on how to process the sand is limited to panning, using a "Micro
Sluice" or a spiral gold wheel.
After panning we always end up with black sand in the gold. The micro sluices work OK but are slow and we still end up
with black sand with the gold. However when properly set-up and run, a spiral gold wheel will process 50 pounds of concentrate
an hour and give you perfectly clean gold!
So if you run lots of concentrate, do not want to sit for hours on end (no pun intended) the spiral gold wheels are worth
GAS OPERATED VACUUMS
The Vac Pac
Everyone I know who owns one of these gadgets loves them. All they are is a gas powered vacuum cleaner using a five gallon
bucket. They are lightweight, easy to transport and will run most all day on a pint or two of gas. It is next to impossible
to thoroughly clean bedrock with a whisk broom and dustpan but crank up one of these babies and you will leave the surface
squeaky clean. VacPacs are a great help in moss mining, crevice cleaning and any other hard to get to or hard to clean place.
They can use all ShopVac accessories so replacement hoses and other attachments are readily available.
Some thoughts on VacPac use
It really helps if you can keep the VacPac lower than the area you are cleaning. It doesn't quite have the power to move all
the rocks that can fit in the hose uphill. As a matter of fact, things go much faster if you toss all the larger rocks out
of the way and just suck up pebbles. If you can't keep the unit below where you are working, lift the hose up above the bucket
to let it clear every so often. These things have a tendency to be top heavy, so I place a suitable rock in the bottom of
the bucket to lower the center of gravity until I have accumulated enough material for stability. Then simply remove the
rock and continue. Don't use the crevice tool unless you have to. The air velocity is higher at the tip but lower in the
hose so clogs are more likely to occur when the crevice tool is attached. If the hose does clog, just raise the hose and bang
on it with whatever is handy. Because the VacPac only collects but doesn't concentrate material, you may want to have a sluice
box or drywasher close by to process the stuff. I usually use my VacPac in dry conditions but when using with damp material,
the inside of the hose tends to clog up with caked mud. A spare hose comes in handy at such times. After the caked mud has
dried inside of the hose, knock it loose and pan out the material, it just may contain fine gold. Speaking of spares, keep
a spare spark plug (and wrench) and an air filter nearby just in case.
Use a small, lightweight drywasher that can be powered by the VacPac motor. It's easy to change from vacuuming to drywashing
and vice-versa. I designed mine (see green example above) so I can vacuum up several buckets of dry material, lift the motor
off and attach it to my drywasher and process the material.
The one complaint I have is under just the right conditions, these gizmos generate a lot of static electricity. I have
given some thought to wrapping a wire around the hose near the end and grounding the wire. Unfortunately, I only remember
this idea when I am up in the digs and actually getting zapped so I haven't tried it yet. Gold Vacuums aren't all that hard
to build and you can save a lot of money by doing it yourself.
Metal Detecting is the use of a "metal detector" to locate ferrous (iron based) or non-ferrous metals. Metal detectors
come in a wide range of designs and many are specifically designed for a particular type of hunting. Some people hunt old
battlefields or bivouac sites of military units, and are looking for "relics" of those units. So, they would choose
a metal detector that is designed for relic hunting. Some people nugget shoot for gold nuggets and want a machine that is
very sensitive to detect the smallest nuggets. Some search beaches or underwater, so detectors are made to fit those purposes.
And some detectors are designed to give good performance over the entire range of activities. Even if you choose the fanciest
metal detector made, with all the latest bells and whistles, it still will not perform correctly if you don't know how to
use it properly. There are machines made to operate simply, but they all must be adjusted to one degree or another, and they
all give visual or audible signals when a "target" is detected. You must be able to operate the machine correctly
and interpret the signals correctly, or many targets will be missed, and worthless targets dug up. It's not the number of
targets detected, it's the quality of targets detected. If you have never metal detected before, and don't plan on metal detecting
for a living (at least not yet) then I suggest getting a metal detector that is moderately priced, with at least these minimums.
1) Ground Balancing (allows the detector to balance itself to the current conditions of where you are working).
2) Sensitivity adjustment (allows the detector to be less sensitive or more sensitive when necessary, especially in areas
with a lot of electromagnetic activity, such as power lines).
3) Volume adjustment (doubt if you could find one without a volume control).
4) Discriminator (to reject trash such as old nails and cans, unless of course that's what you're after).
5) Visual and audio target identification, showing depth to target and target ID (quarter, nickel, dime, etc.).
Don't just run out and buy the most expensive machine you can find. They might be worth all that money, but only if you're
going to use it enough to pay for it. Less expensive machines can give acceptable performance with a lot less money.
Where to metal detect? That depends on your target. Gold nuggets? Obviously you would not search in the local school yard.
Search out those areas known to produce gold nuggets. Many recreational prospecting and metal detecting clubs have claims
that members can work. There are also areas open to the public that can be worked. If you're after coins, you need to search
areas that have been frequented by lots of people. Parks, ball fields, church yards, fairgrounds, beaches, school yards, and
the list goes on and on. What about relics? Old battlefields, bivouac sites, march routes, wagon trails, old homesteads, ghost
towns, and once again, the list goes on and on. What's the bottom line?
RESEARCH - RESEARCH - RESEARCH
Research will save you hundreds of hours searching areas that have not, and will not, produce that which you seek. Where
can your start your search? Right here. http://www.therockerbox.com/metal_detecting1.htm Hundreds of ghost towns and hundreds
of lost treasure stores are listed in the RESEARCH area, and more will be added continuously. Where else? Libraries, bookstores,
newspaper archives, history books, magazines, local residents, and the list goes on and on. There is literally an endless
supply of information about what you want to find and where you want to find it. You just have to look.
Anyone, young and old, can go metal detecting. Anyone can find treasures with their metal detector. It doesn't take a
lot of machinery to do it, just a good metal detector.
Some...not all...of the data on this web page was blatantly plagerized from other websites
If you find this to be repulsive...contact me and I will remedy the situation by removing the
offending data or linking back to the site of origin...Thank you
This SITE was created for the HUACHUCA PROSPECTORS ASSOCIATION by phred
E-MAIL phred022001@yahoo dot com with COMMENTS or SUGGESTIONS about this WEB SITE.
Created APRIL 2008