By GBE Mandrel Bending
I have been making Gold dredge nozzles in our business for quite a few years now and we sell them on our website and Ebay. We make them in 2", 2-1/2", and 3" OD Tube with slip on connections. Plus we give the customer the choice of a classifier or not, welded to the nozzle tip instead of charging extra for a "bolt on" accessory when they should be included.
We always have made them with 1-1/2" OD tubing either slip on hose or threaded hose to the water pressure line with a reducer to increase the pressure to the nozzle.
Are there any people who use 3.5" or 4" or even 5" nozzles? If so, what sized water pressure tube do you run for those? I am thinking about making a bigger product line for our customers and am all ears in your input.
What would be your best nozzle? Short and stubby? with or without side handles? Different nozzle sizes? Water inlet tubes?
I am also thinking about making them out of 316L stainless for the salt water people's.
Any ideas would be greatly appreciated.
Sincerely, Steve Stabler-Owner
GBE Mandrel Bending Inc.- GBEMANDREL.COM
We make them with OUR made parts, no someone else's.
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!
To start with I think the Keene over size jets and couplers are great. Over the last few weeks of dredging I can count on one hand how many plugs I had had in the jet. People had told me in the past they have had trouble with them sucking air. What I do is double up the gasket with a cam lock gasket to make a good seal.
The problem I am having is getting the coupler on to a new hose.
I have put a few of the couplers on the years but it is always so difficult to get it to go all the way on.
I was wondering if anyone had a good technique or procedure to make it easier?
Last night I read a very interesting (IMO) article by Chris Ralph in the June, 2019 issue of the ICMJ (https://www.icmj.com/) titled "How Long Does It Take to Find and Recover an Ounce of Gold". There are a lot of caveats Chris lists, which makes it dangerous for me to summarize what was written. Further, there is a fine line between showing results from a magazine/journal which needs money to stay afloat and requiring interested parties to simply pay for a subscription. IMO, anyone halfway serious about searching for native gold (and there's more there than just gold) should be a subscriber. Most importantly, his estimates certainly depend upon the ground you are covering -- this should be obvious to everyone and I hope simply mentioning it will squelch any attempt to quibble at his results. Basically there is a lot of uncertainty around Chris's numbers, which he is well aware of, but it's still interesting to hear from an expert who has used all of these methods countless times. I was surprised at some of his estimates. In order longest (least efficient) to shortest:
Panning: 42 hrs,
Metal Detecting: 40 hrs,
Sluicing/Highbanking: 30 hrs,
Dry Washing: 30 hrs,
Dredging: 20 hrs,
Hard Rock Mining: 8 hrs.
I think it's worth emphasizing that this is a time efficiency, not a cost efficiency. Panning is clearly the least expensive with hard rock mining by far the most. Chris also points out that the leadup time/research/preparation & cost are vastly different -- hard rock mining being the obvious extreme.
Had a great weekend out prospecting and dredging a club property in Virginia. Got to meet some new people and have an overall great time camping and dredging.
So i just started prospecting this creek and club property this year. Ive panned and dredged it a few times, all was basically sampling activities. From research of old workings and looking geologic and lidar maps i choose a specific area to focus on, and the last time out sampling with the dredge started to sniff on decent gold in a 1 hour sample hole with a 4 inch dredge. The area consists of a spot about 100 yards wide in which the creek has always had to cross since sheer cliff walls bound the stretch on each opposite bank. A gold bearing feeder also comes in within the stretch which is an added bonus. The thought is, is that since the creek has always had to cross that 100 yard stretch then an old paystreak should cross it somewhere was well, from back in the days when this area had more conducive climate to being able to transport gold.
From what ive heard and seen within the club most people avoid prospecting this creek, due to difficult access, deep overburden and generally not finding much gold once they get in there. So i have not heard of decent gold coming from it. But the old history reports say otherwise and state that it is one of the few creeks in this area that was never placer mined due to difficulties that the old timers in the 1800s couldnt overcome. Sounds like my type of area, if im going to prospect a club property.
Sample dredging the creek a few weeks before Memorial day weekend. Notice the 15 foot tall silt bank behind the dredge, its all alluvial flood plain material.
Gold from the 1 hour sample hole with the 4 inch dredge. Not fantastic but far above the back ground gold count for this creek.
Camp all set up and the dogs are happy with it.
Getting the dredges set up. I decided to bring the 5 inch since the ability to move more material out weighed the extra weight in my opinion.
Dredging away. Luckily the overburden depth was only about 2 feet at most, so i was able to cover some ground with the 5 inch. Got about 2 full good days of dredging in.
Found some Indian pottery while dredging. Always awesome to find Indian artifacts.
And the best part, Success! Good gold with some nice pickers. 2.4 grams on Saturday and 1 gram on Sunday. I love when research, sampling and hard work culminates into some great cleanups in new areas.
Got a new spot to continue to work know, and i know there are more pickers and possibly nuggets nearby, just gotta get my dredge nozzle over them.
Hope everyone else had a great memorial day weekend.