With skill and patience it has been found that the loose materials bit can also sometimes be used successfully with the addition of dry bentonite to make sleeved borings in wet, flowing (heaving) sand. The way this is done is by pouring dry bentonite chunks into the boring or by smearing largely dry but hydrating dry bentonite powder onto the flights of the loose materials bit. The swelling, gelling material is forced onto the sidewalls by the rotating bit where it mixes with water and sand to form a stiff, relatively stable paste.
Another frequently occurring but easily avoidable problem is lugging of the engine. Run the drill fast at full throttle whenever it is working. The engine must run fast to produce full power and to cool itself. The diamond bit must also turn as fast as possible to effectively cut rock by grinding. The operator must "feel" for the right engine speed in each drilling circumstance. The pitch of the working engine at which the diamond bit advance rate is maximized must be his guide. Engine lugging very quickly results in fatal overheating of engine and transmission due to both centrifugal clutch drum slippage against the clutch shoes and consequent frictional heat buildup and loss of cooling fan effectiveness at low rpm.
Diamond drilling in rock effectiveness is also dependent on the volume of water used. Water both cools the working bit and removes the rock grindings. If insufficient water is used the bit can quickly heat up to the point at which it can partially melt either or both bit and rock. The ideal amount of water needed is that at which the rate of drilling advance is greatest but water use is minimal. Some drillers say that the ideal is indicated by a return water which has the viscosity of buttermilk and a warm (steaming in cold air) temperature.
Rock core sampling is usually easy, as cores of most kinds of rock tend to break into small pieces due to natural rock jointing (fracturing) and these fragments usually remain in the threaded lead body. Usually a push with the use of the knockout rod from the diamond core bit toward the tail of the threaded lead brings the rock core pieces to the back of the threaded lead for collection. These cores can then be placed in labeled, clear plastic tubes and or in core boxes.
Adjustments of belts and straps ought to result in a pack which exerts its weight primarily on the user's hips rather than on his or her shoulders. The pack should be snug to the body but not uncomfortably tight and ride as high as possible on the wearers back.
10160 Oak Ridge Road
Yamhill, Oregon USA 97148
For a printable PDF version of the operators manual please click on this link PDF OPERATORS MANUAL
TABLE OF CONTENTS
All components of a basic Shaw portable core drill kit can be carried in its frame backpack as a complete kit weighing about 50 lbs. (19 kg). The backpack itself has several main straps which must be adjusted to fit the user: one for adjustment for wearer torso length, two at the sides of the user’s chest for snugness to the body and pack positioning, and a hip belt over the wearer’s waist.
TORSO LENGTH ADJUSTMENT STRAP
HIP BELT ADJUSTMENT STRAP
SHOULDER ADJUSTMENT STRAPS
When the loaded Shaw portable core drill pack is opened the first item to appear is the engine drill.
TOP OF BACKPACK
GASOLINE AND 2-STROKE OIL
RECOMMENDED 30:1 GASOLINE TO 2-STROKE ENGINE OIL MIXTURE
2-stroke engine oil
To start the engine, press the ON-OFF switch on the handle to the “on” position.
Adjustments to fuel air richness can be made by turning the adjustment screw on the side of the carburetor. Fuel richness must be reduced (clockwise) at higher elevation and increased (counterclockwise) at low ones. At full throttle operation turn the adjustment screw clockwise a little until the engine begins to run unevenly. Then turn the screw counterclockwise until the engine runs smoothly and at a high pitch.
CARBURETOR ADJUSTMENT SCREW
Push the flexible rubber priming bulb behind the carburetor (somewhat hidden from view) several times to pump fuel from the fuel tank to the carburetor. Then push the red choke lever to the choked (closed) position. Pull the start cord several times until the engine fires a little. Push the choke lever to the un-choked (open) position.
CARBURETOR PRIMING BULB
Run the engine for a minute to warm it up before drilling. When under load (working),the engine ought to be run at full throttle and at a relatively high angular velocity (rpm). High rpm is needed because the engine will otherwise overheat. Low engine rpm (lugging) causes slippage of the centrifugal clutch and failure of air cooling by the fan blades ahead of the engine.
Maintenance requirements for the engine drill include periodic replacement of spark plug and air cleaner.
AIR FILTER COVER
WATER SUPPLY SYSTEM
Water supply system component water swivel and ball valve are mounted on the engine drill.
Water tanks, either compression bottles for backpack access only drilling or larger tanks with electric pumps mounted on motor vehicles and water hoses from these to the engine drill are water supply components external to the drill.
WATER SWIVEL SLEEVE AND SHAFT
COMPRESSION WATER BOTTLES
25 GALLON WATER TANK WITH 12 VOLT PUMP
Inside the swivel sleeve are six Teflon impregnated rotational quad rings. These quad rings are lubricated with silicone grease.
QUAD RINGS IN WATER SWIVEL SLEEVE
Both quad rings and grease must be replaced at intervals. The sure sign of the need to replace these components of the water swivel seal is water leaking from either top or bottom of the water swivel sleeve. To perform this replacement remove the water swivel from the engine drill spindle with a pair of wrenches, then disassemble the swivel itself with the use of retaining ring pliers.
REMOVING QUAD RINGS
REMOVING WATER SWIVEL RETAINING RING
COMPRESSION BOTTLE O-RING (BROWN) FOR CAP SEAL
Larger water tanks with electric on-demand pumps are greatly preferable to compression bottles as they provide much more water volume and a steady, high pressure. Normally these larger tanks must be carried on vehicles of some sort such as ATVs, pickups or boats which can also supply 12V power. Alternatively the pump can be used with a battery and other sources of water such as jerry cans or a body of water itself such as a creek, lake or sea.
PUMP, BATTERY AND WATER CONTAINER
REPLACEABLE DIAMOND BITS
To be effective in cutting rock the replaceable diamond core bit must be rotated at a high angular velocity as measured in RPM and it must be as rough as possible. Producing or maintaining bit roughness is called bit dressing. Bit dressing is accomplished by rotating it fast and hard in an abrasive material. Many, perhaps most kinds of rock are quite abrasive enough by themselves to dress bits. Very hard rock such as quartzite, however, are not very abrasive but tend to smooth diamonds. Once smoothed, the diamond bit will no longer cut rock. In drilling such poorly-abrasive, but diamond wearing material, the bit must be frequently abraded by dressing. Materials to be used for bit dressing are dry, fresh sandblast grit, natural rock sand, sandy soil, or wet sand on riverbanks or beaches. As dressing proceeds the bit diamond crystals are exposed as the metallic matrix between crystals is worn away. A dressed bit will sparkle in sunlight and will cut rock easily.
DRESSED ELEPHANT TOOTH BIT
DRESSED DIAMOND BIT
DRESSING (ABRADING) BIT IN SANDBLAST GRIT
UN-DRESSED (SMOOTH-FACED) DIAMOND BIT
Removing and replacing Shaw diamond bits usually requires the use of a pipe wrench for a grip on the shoulder of the bit body. The tail of the lead can be secured with the Shaw stainless handle. Wrap the threads of new bits with Teflon tape for later ease of removal.
REMOVING A REPLACEABLE BIT FROM THE THREADED LEAD
As mentioned before the lead holds the replaceable diamond bit and receives and usually holds rock cores. It is made to release cores from the back. Cores in the lead may be dislodged if temporarily stuck by pushing them backward from the bit mouth toward the lead rear with the use of the knockout rod. The lead requires the use of an adaptor to mate it with the water swivel shaft or extensions.
THREADED LEAD BIT END
THREADED LEAD TAIL (TWO J-SLOTS)
THREADED LEAD HEAD WITH KNOCKOUT ROD
THREADED LEAD TAIL WITH CAPTURED ROCK CORE
Available with either stainless steel or aluminum tube bodies, extensions are the main building units of the drill string. They couple and de-couple very easily if male and female mated parts of the bayonet couplings are clean and lubricated with silicone grease. Coupling is done with a simple push-and-turn motion and de-coupling is done with a turn-and-pull one.
COUPLED EXTENSION ENDS
MATED EXTENSION MALE AND FEMALE ENDS
LOOSE MATERIALS BIT
Coupling with an initial turning motion - a natural inclination - actually causes o-rings to loop up and subsequently be cut. A simple push and turn is both easier and far less destructive. When dis-assembling drill string when removing it from a boring, it is best to take it apart in small pieces of two or three extensions each; longer pieces of drill string are unwieldy and can be accidentally bent.
BENTONITE POWDER SOMETIMES USED WITH LMB
LOOSE MATERIALS BIT (LMB)
The core breaker is used to snap off rock core which remains intact in a rock boring. Acting as both hammer and a wedge, cores of brittle rock will break at some point in their length when struck a sharp blow with the core breaker. Once broken, the core pieces can be captured with the core catcher.
The Shaw core catcher grips pieces of rock core for retrieval. The spring stainless steel tip of the catcher has three inward bent tabs. Once the catcher has been pushed over the top of the core the tabs tend to grip and hold it. All retrieved cores ought to be pushed from the catcher tip backward with the knockout rod.
A small but necessary tool, the knockout rod is needed for punching cores or soil lodged in the bit mouth backward toward the tail of the threaded lead. Once cores or soil have been forced out then the knockout rod can be used to scrape out and clean away clay smeared on the inside of the threaded lead.
25 MM x 41 MM ADAPTOR
The 25 mm x 41 mm adaptor is used in the rare case where a 25 mm part is must be coupled to a 41 mm drill string. This is necessary for soil sampling with a 41 mm kit of equipment because the Shaw soil sampler must be small for adequate hand penetration. The adaptor can be used anywhere in the drill string from the handle onward.
COUPLED 41 MM X 25 MM ADAPTOR
41 MM X 25 MM ADAPTOR
The Shaw soil sampler is very nicely engineered for ease of use and for the exceptional quality of its undisturbed samples captured in well fitted, clear plastic tubes. The soil sampler is pushed - not turned - into soft materials. This gentle but forceful method produces the long, undisturbed soil samples with stratigraphic orientation, color moisture content and chemical integrity exceptionally well preserved for analysis or archival.
SOFT SOIL SAMPLER WITH SHARP-EDGED TIP
"T" HANDLE SOFT SOIL SAMPLER WITH SHARP-EDGED TIP
FILLED AND CAPPED SAMPLE TUBE
LOADED SOIL SAMPLE TUBE AT SAMPLER TAIL
For those circumstances where open hole boring is impossible, as in loose sediments or flowing sand, casing may be used to advance borings with the use of the Shaw drill. To accomplish this, a water injected casing driver is attached to a 25 mm drill string locks into and drives a threaded casing shoe. The threaded casing shoe, in turn, is attached to a series of sections of threaded PVC casing. As the boring is advanced and extensions and casing sections are added above the ground surface, all parts are locked together. On boring completion the drill string and driver are retrieved and the casing and its attached shoe are left in place.
CASING DRIVER, CASING SHOE AND PVC CASING
The casing driver equipment described above can be used for installation of shallow groundwater monitoring and domestic wells.
Other components of Shaw drill kits include a spanner wrench for moving the water swivel drive pin or pins, spare o-rings to replace those on the male part of extensions and water swivel shaft, a tube of silicone grease (other kinds of grease will also work in a pinch), a spark plug and spark plug wrench.
To avoid “walking” of the diamond core bit on hard rock begin by cutting a small groove in the rock surface by holding the bit at an angle to the vertical.
Once cut, the rock surface groove acts as an anchor point and from it the working bit can be slowly rotated to the vertical (or any other position) for the boring. Once the boring is properly started set the water valve for the minimum amount of water volume needed in the circumstances. The faster the cutting rate the more water is needed to rinse away rock cuttings. A lot of water is needed to deal with clay seams in rock.
One of the greatest problems in rock drilling is loss of water circulation (boring wall leaks) in voids and fractures. With loss of circulation the boring above the boring wall leak is left without lubrication causing sidewall frictional resistance. Bentonite or polymer additives to drilling water are very effective in sealing leaks in boring walls and avoiding this problem. Baroid Company www.baroididp.com through its many worldwide distributors offers a fine variety of drilling fluid additives.
41 MM ROCK CORES IN CORE BOX
25 MM ROCK CORES IN CORE BOX ( TWO LAYERS)
CLEAR PLASTIC SAMPLE TUBES
For core drilling in confined spaces such as mineshafts without ventilation it is far the safest plan to use an electric drill motor rather than a gasoline engine. Gasoline engine CO2 and CO emissions are both quite lethal. The recommended electric motor (below) is the High Speed (1750 rpm) Milwaukie Hole-Hawg. This electric motor is powerful although heavier than the Tanaka 27 cc two stroke engine. Shaw Tool provides an adaptor for mating its water swivel to the Milwaukie drill chuck. As the Milwaukie electric drill lacks a centrifugal clutch, it is difficult to control if the working bit or drill string suddenly binds up during drilling.
ELECTRIC DRILL MOTOR WITH WATER SWIVEL
Copyright © 2011 Shaw Tool Company. All rights reserved. Shaw tools are protected by U.S. Patent No. 6,102,135 and patents pending
Deeper (>10m) borings can be made with Shaw Tool equipment. The primary limiting factor in this process is the increased weight of the longer drill string required. Shaw Tool offers a fairly lightweight (53 lbs., 24 kg.) tripod which can be used with light block and tackle to make lifting heavy drill strings a little easier. Use the handle to make connection to the female coupling (upper) end of the drill string.
SHAW TOOL CUSTOM MADE TRIPOD USED FOR LIFTING HEAVY DRILL STRINGS
The stainless handle is used to lift, push or turn the drill string by hand. It is needed especially in sampling rock core with the core breaker and core catcher. When a drill bit gets stuck for any reason the handle becomes an important tool for twisting free. Like drill string components this tool must be kept clean and lubricated.
ESTABLISHING ROCK SURFACE ANCHOR POINT
VERTICAL ROCK BORING
BAROID QUIK-TROL HOLE STABILIZER
The loose materials bit works by disturbing soft materials with its carbide blade, mixing the disturbed cuttings with water to form a dilute mixture of the material (mud) and forcing it under pressure up the boring annulus to the ground surface (or a fracture zone intersecting the boring). The volume of water to use with this bit depends on the drilling circumstances but the usual rule is that more water, and at high pressure is better than too little. Hard clays are often the most difficult of all to deal with; it is best to proceed slowly in drilling this material and to use lots of water in order to keep the bit free of sticky clay buildup.
The water injected loose materials bit included in our standard kits may be used for boring soft materials including rotted rock, clay, soil, muskeg, muck and sand. Soils with clay components often naturally produce sleeved borings but well sorted sand or even heaving sand may be sleeved with commercially available bentonite which is a dry, natural, swelling clay mixture (smectites) which on hydration produce an oatmeal-like paste useful for sealing and strengthening boring sidewalls.
Many field investigations require penetration and/or sampling of soil. Simple penetration is best done with the loose materials bit. Undisturbed soil sampling is best done with the Shaw push-type soil sampler. The diamond core bit can be used to penetrate and sample overburden rocks or boulders.
As mentioned above the loose materials bit can easily penetrate soft materials including soft rocks like shale and weathered rock of many types. As this kind of bit grinds away everything in its path in theory it need not be withdrawn as its boring proceeds. In practice,however, the LMB is often fouled by clay and must be withdrawn for cleaning. Use of surfactants in the drilling fluid helps to prevent bit fouling by suspending clay platelets which oterwise accumulate on bit surface.. Baroid can help with the bit fouling problem.
Many subsurface materials are heterogeneous including both hard materials and soft materials. By alternate use of the LMB and diamond core bits most materials can be both penetrated and sampled. This alternation is easy to do with Shaw portable equipment as both LMB and diamond core bits of 25 mm or 41 mm OD are of the same outside diameter and thus entirely interchangeable and because the bayonet couplings are very easy to couple and de-couple.
As the water swivel shaft projects from the engine drill spindle it is best to avoid knocking it about unnecessarily. Being hardened the shaft itself will not easily bend but a heavy blow could bend the engine drill spindle or damage the bearings of the transmission.
Replace the worn rings with new ones, liberally re-lubricate both the shaft and sleeve with silicone grease, re-assemble the swivel and thread it back onto the engine spindle by hand. Remember to put Teflon tape on the spindle threads.
The quad rings of the water swivel are quite wear resistant but they must be exposed only to clean water and or drilling fluid and kept well lubricated with silicone grease. A muddy water supply to the swivel will soon groove its shaft and ruin the Teflon quad rings.
The ball valve mounted on the engine drill handle can be nicely adjusted to serve drilling requirements without wasting water. It is often best to open this valve completely when using the loose materials bit for maximum flushing action. Connections with the water hose are made by pulling back the spring loaded fitting behind the valve itself. No maintenance is required for the ball valve.
The compression bottles of the backpack drilling system for a limited water supply in otherwise impossible of access drilling locations sometimes require patience in their use. A head space of air is required over the water surface in a filled bottle which can be compressed to drive out the water to the drill. Sometimes the screw cap must be tightened more than once and forcefully to achieve a seal of the large o-ring under the cap. The hand pump must be used with diligence until real resistance indicates a sufficient compression of air in the headspace of the bottle.
Shaw Tool has replaced one set of pinion gears in the transmission to increase the angular velocity of the power output. This alteration results in substantial improvement in bit penetration rates.
The Tanaka 27cc engine is a two stroke one which requires mixing of two stroke engine oil with regular gasoline in a ratio of 30 parts gasoline to 1 part engine oil. Tables of mixing quantities are printed on oil containers.