Model 625 HD GOLD Prospecting Hand Dredge
Model 625 HD YouTube Description of Components
The Model 625 Hand Dredge, works much like a typical motorized recreational suction dredge, only the suction is Immediate Vacuum Response (IVR) and not dependent upon a power jet venturi and impeller produced siphoning vacuum, (vacuum that's driven by the mechanical force of gravity. See: "hydraulic mining monitor") type water pressure that's forced angularly into the dredge hose cavity. The convoluted cylinder bellows "HG Power Plant" is reinforced from inside and out making the operation more like a "rocking" piston pump. Best of all, it's ported to effortlessly pass 1 1/2" diameter cobbles, or attach the large 3 1/2" inner diameter, 1/2" mesh seive nozzle for suctioning and pumping massive amounts of pre-classified dredge material with fine gold into a free flowing sluice or a side loading bucket. Effortless operation makes all day GOLD hand dredging possible.
Click Here M625 and M2125 GOLD Nugget YouTube Video
With a single elongation stroke of the HG Power Plant, the M625 hand powered suction GOLD dredge is capable of producing enormous suction at the intake nozzle attributable to it's sealed chamber construction. Pulling the handle can more than double the mechanical force of the incoming water when compared to siphoning and improves the potential for gold recovery from cracks and crevices. See Video
The Model 625 was bench tested using a vacuum gauge 
and consistently held a -10 in/hg, that's more than 1/3 of an atmosphere. That figure translates into more than enough air friction or watery mechanical force to get any GOLD moving through the dredge. For the 1 1/2" dredge gauge test, the M625 HD was fitted with 24" of thin wall class 200 1 1/2 in. PVC pipe, providing a 55 cubic inch chamber that would hold approximately 30 1/2 fluid ounces.
Atmospheric formula
1 atmosphere (29.92 inches mercury) = 14.695948775 pounds per square inch
1/3 of 14.695948775 = 4.898
1.71 I.D. /2 = .855r
(.855r x .855r) x 3.14159 (pi) = 2.29658
4.898 psi x 2.29658 sq. in. = 11.24866lbs.
This calculates to 11.2487 lbs. and would be a tremendous amount of weight that could be held to the end of the 1.71 I.D. nozzle. Compare that to the world famous TV vacuum cleaner commercial that used a 16 pound bowling ball to prove their product and that was with a 6" cone so that created a larger area to apply vacuum over, still experts place the water lift of that vacuum at 65", so the model 625 is twice as powerful.
During the pump down phase, the slurry of sand, gravel, and gold that was on the way up the intake pipe may loose momentum and begin to fall back, but a rapid succession of pump strokes will keep it moving towards the pump virtually walking the dredged material all of the way up and into the pump. Model 625's can pump over 25 gallons of water per a minute.
On average, siphons 1625 gallons per hour (27+ gallons per minute), and simplifies siphon dredging by serving as the priming device to keep the siphon alive. Adding extra hose is recommended, or upgrading to 2" hose to reduce 1 1/2" plug ups.
Model 625's disassemble for repair. A full line of replacement parts mainly flappers, fasteners, and HG Power Plant Shells (convoluted cylinder bellows) are the main items, insure a longer dredge life.
Model 625 Hand Dredge includes:
(1) Model 625 HD Pump Body
(1) Model 625 HD 1 1/2" dredge kit consisting of:
(2 ea) 1", 1 1/4" and 1 1/2" x 12" long thin wall PVC pipe (pre-cut and deburred)
(1 ea ) pipe section connector coupling sizes 1", 1 1/4" and 1 1/2"
(1 ea.) 1 1/2" X 1 1/4", 1 1/2" X 1" pipe connector reducer bushings
(1) Model 625 HD Discharge Valve
(1) 90 degree Maxi-Port Black elbow
(1) 1 1/2" X 3 1/2" Reducer coupling with 1/2" mesh (seive nozzle ABS Black)
(1) steel reinforced combo nozzle 1 1/2" and 1 1/4" compatible (slp/spgt)
(1) auxiliary 1 1/2" coupling
(1) 3ft x 1 1/2" Teleflex Marine wire reinforced Vinyl/PVC hose assembly
(1) 2" multi function spring clamp assembly with 90 degree elbow
(1) 1 Teflon Tape
(1) 50 lbs capacity Sand Bag
Add a Pump cover (shown in picture) from the list below for $5.00 extra
Add the 1 1/2" 90 Degree MaxiPort Elbow (slp/fpt) and 2" dredge hose along with the (2) 2" to 1 1/2" hose adapters to eliminate most all plug ups from rocks suctioned in that are at the 1 1/2" threshold.
Now available........ New Side Loading Bucket Lid fixture for the EGTC GOLD Concentrator. The window allows the EGTC to snap right in. Fits most 3, 5 and 7 gallon buckets.
The EGTC was discovered trying to design a "Picker Trap" while serving as a motorized dredge style Header Box for the sluice in hopes that it would give a preview of what to expect from the sluice clean out. Each clean out of the EGTC built anticipation as to how much GOLD could be expected, except that on each occasion, the GOLD never escaped the EGTC! So, the sluice clean outs were without any GOLD, not even any color!
EGTC Gravity Trap Gold Concentrator Model 2125 HDP Clear 2" Gold Hand Dredge
A list of parts and accessories below allows for changing the Hand Dredge. Placing a single check mark in any categories box can upgrade to, substitute for, (as in another type of hose), "Un-Build" the dredge (* Negative Value). Prices adjust when add to cart is selected.
