These guys do some really good gold dredging videos. They have a Youtube channel all about it but this is their latest video that they've made after we came out of lockdown in NZ. The water would be pretty damn cold as lockdown took us towards winter!
They find some pretty good gold! You'll see them smashing out the rock with rock hammers to free up nuggets hidden in the rock. A fair bit to learn from their videos.
I am posting this here since there are folks on this forum from Arizona. I was wondering if anyone might have information like rules, regulations or possibly links to which agencies regulate and permit suction dredging. I know, there is not much water in AZ, but there must be places that a person might find gold in streams.
By Dean Stone
Hi all, hope everyone is ready for dredging . I have a 2" Keene dredge, with the hard floats. Dose anyone how much air to put in the floats? Don't want to blow them up, but need them to float good. Any help would be good, I tried to look on line but could not find how much pressure to put in them. Thanks Dean
I purchased a newer Keene 6” mini dredge last year with GX270 motors and PHP 500 pumps. I used it quite a bit last summer but it was all in the old mine cuts that we dredge in. Not once in a river. The suction is unbelievable.
My question does anyone have experience with the bigger motors needing more floats because of the weight? The motors themselves are 20 lbs more a piece and not to mention all of the weight from the water volume and hoses being bigger. Keene makes the outriggers with floats for them. I was going to make something similar uses two 30 gallon poly drums.
Been messing with this project on and off for a few years now. Finally got it where it was ready to be tested this past weekend.
Was originally a keene 3 inch with 4 hp motor and p160 pump i believe. I sold off most of the 3 inch parts and started building the components need to turn it into a 4 inch. From the 3 inch all that remains is the frame, floats and motor and pump combo. I bought a 4 inch flare from keene, since i have no good way to fabricate a lightweight flare. Everything else i have been working on fabricating, primarily being the sluice (16x40), riffle trays, and the power jet.
The power jet is were i diverged from most of the current designs that are widely used. I wanted to build a 4 inch as light as possible while still using the 4hp motor and pump combo, as most the streams i work are shallow and dont require huge amounts of suction for dredging at great depth. The problem was that the 4hp motor and p160 pump struggled in my mind to provide adequate suction to the 3 inch even when near full throttle. Based on this i decided to build a copy of a dahlke tri-jet which should allow a 4 inch to be run off of a smaller motor and pump when compared to a normal 4 inch, due to increased efficiency over a standard style of power-jet.
Pictures of the tri-jet in various stages of completion:
Picture of the sluice and riffle tray, first iteration with woven wire:
Testing day! Couple of issues were noticed while testing. There were a few leaks in the power jet, the woven wire was too open and large rocks would get stuck on it, the high pressure hose was way too long and since it was inch and quarter and so is the pump output , it was constricted to less than inch and quarter at the coupling areas, and the long high pressure hose probably caused a loss in pressure due to friction. The power jet should also be mounted not right at the flare but a few feet from it, so that the hose acts as a longer jet tube and helps increase suction, a 20 ft suction hose also didnt help.
But regardless i was able to dredge with moderate suction, with it. So the test was a success, and with the various refinements it should have greater suction and water flow.
Then the next day, the various refinements and fixes from the problems noted during testing. Replaced the woven wire with 3/8 inch 40% open punch plate, moved the jet so it is mounted about 3 feet from the flare, shortened the high pressure line and increased it to 1.5 inch so there are no restrictions, patched the holes in the power jet, and painted it. I do have a question or everyone, would increasing the size of the footvalve and intake hose from 2 inch to 2.5 inch help increase the gpm of the pump at all? The footvalve cage that came with the keene pump seems small to me. I have some pictures below showing the difference.
I look forward to hearing from everyone! It was a fun project!