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PROSPECTING
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portability
A complete kit of Shaw placer sampling and hard rock coring equipment in its backpack, including two gallons (8 l.) of drilling fluid, weighs about 55 lbs. (25 kg). An average man can carry this load through shallow streams, on sometimes steep trails through rough country or forested areas and up or down steep slopes. Such backpack kits can be carried in the boot of a car, in a pickup bed, on the rack of an ATV, in a small boat or raft, or on a horses’ back.
dual-purpose
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By carrying both a placer wide kerf sampling bit mounted on its own core barrel and a narrow kerf, fast cutting rock cutting bit mounted on its’ core barrel, a prospector can quickly switch between collecting rock cores or placer deposit cores in his wilderness investigations. Both of these tools use the same compression bottle water supply, engine, water swivel, and reliable bayonet couplings which can be opened (usually) by hand.
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low fuel usage
The relatively tiny Shaw Gen3 Kawasaki J53 two stroke engine consumes about one quart (1 liter) of mixed petroleum fuel per running hour. But drilling and sampling is an intermittent activity; actual engine run time is less than half that. Therefore, it is reasonable to top off the engine fuel tank and then carry a one-gallon (4 L.) container of mixed fuel into the field for a full day of prospecting work.
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low water usage
Polymer gelled water, being substantially more viscous than un-amended water and therefore capable of carrying much greater drill cuttings loads, is far more efficient than pure water as drilling fluid. Much less of it is needed.
Suggested prospecting handheld kit 2 meters
$6,160
FREQUENTLY ASKED QUESTIONS
Q. For successful use of Shaw soil sampling equipment, how important is it to add polymer (e.g. EZ Mud) to drilling water?
A. Hugely. Polymer amendment (1) greatly reduces water usage, (2) allows drilling and sampling of clay by its’ clay encapsulating behavior, (3) lubricates the rotating drill string, the non-rotating sampler capsule and the soil sampler core bit, and (4) prevents clay sticking to metal surfaces of the drill string, drilling fluid injectors of the bit, and the bit segment cutting surfaces.
Q. How much polymer should I add to my drilling water?
A. To prepare drilling fluid, tiny amounts of polymer, either in liquid or dry form, should be sprinkled in slowly and carefully into water while mi as it is a very powerful gelling agent with vigorous wire whip or electric tool mixing, into clean water until the resulting mixture reaches the viscosity of a smooth, no lumps, gelatinous (ropy) medium syrup. The resulting fluid will naturally stratify into high viscosity and a low viscosity layers in short time; therefore, it must be re-mixed with the whip or stirring rod every thirty minutes or so.
Q. How important is it to precisely measure the gasoline and two-stroke engine oil components for the Shaw drill Kawasaki TJ 53 engine to achieve a 50:1 ratio fuel mixture?
A. Exact measurement of two stroke engine oil and regular gasoline for use in the Kawasaki TJ 53 engine can hardly be over-emphasized. A slightly reduced gasoline to two-stroke engine oil ratio fuel mixture can, and unfortunately for Kawasaki 53 owners, does, sometimes result in an irreparably burned piston head and cylinder walls. A too high oil to gasoline ratio mixture causes oil fouling of spark plug, carburetor and muffler which, in turn, which can make engine starting impossible.
Q. If the Shaw soil/placer sampler is substantially different than other types, how does it work?
A. There are several mechanical features of the Shaw sampler which allow it to sample loose gravel deposits, even underwater: (1) a skirted, water injected diamond core bit which cuts pebbles and fine gravel but directs drilling fluid around and then through bit injector holes outside of a sampler tube and sampler, (2) a closed capsule sampler which protects captured sample material from drilling fluid erosion, (3) limited bearing surface sampler cap which prevents torque transmission from the bayonet coupling , and (4) a valved air vent mounted in the cap which prevents air compression inside the sampler capsule, and, after sample capture, holds it inside by vacuum (clam gun effect).
Q. What drill penetration rate is best for placer/soil sampling?
A. This must be determined by the Shaw drill operator, depending mostly on the earth material being penetrated. For example, a soft, sandy silt placer can reasonably be penetrated fairly quickly, as long as drilling fluid moves to the surface easily, indicating good drilling fluid circulation. A rocky placer lens, on the other hand, would necessarily take longer to penetrate even if the rocks were soft, comprised of, for example, limestone (Mohs scale 3). An even slower rate of penetration would be required if the rocks were very hard, such as those comprised of granite (Mohs scale 6.5 - 8.0 or jadeite (Mohs scale 7.0 – 8.0). A slow rate of penetration would certainly be called for when drilling in clay, which is probably a core driller’s worst enemy due to its diamond bit “slicking” behavior and its great adhesiveness to drill string metal parts.
A general rule of thumb to follow in maintaining a sustainable and efficient drilling rate is to act according to working engine sound. If the engine sound (pitch) is low, the engine is being overworked and the transmission centrifugal clutch shoes might be slipping inside the clutch drum, leading to likely failure. If a working engine has a high pitch, this indicates that the diamond bit has somehow worn smooth and it is not cutting: bit dressing or filing or both, or application of more bit weight are indicated.
Q. Diamond bits can be quickly worn in abrasive soils or placer sand. How can excessive bit wear be avoided?
A. Shaw soil sampling bits are made with wide sintered diamond segments with generous clearance on both internal and external surfaces for extended bit life. These segments are made with a hard (high cobalt concentration) matrix and high diamond concentration to resist abrasion.
Q. If drilling in placer gravel and sand in river bedload deposits, can the driller expect his boring to stay open after retraction of the core barrel and lengths of drill string?
A. Usually, yes. Generally speaking, drilling water, well mixed with polymer additive and used sparingly will form an adequately strong “wall cake” which will prevent boring wall collapse during or after drill string and core barrel removal. If the borings do collapse, then more polymer should be added to the drilling fluid to increase the strength of the wall cake.
Q. Are two-inch diameter placer gravel cores affected by polymer amended water drilling fluid?
A. Not much. Shaw drill placer cores are coated with a mixture of viscous drilling fluid and rock cuttings, but this minimal coating can be instantly rinsed away by gold panning or sluicing.