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[omnicron]

Yes I would build it myself but don't have a lathe

 

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[principedeleon]

Yes I would build it myself but don't have a lathe

I dont know in your town but here theres places with all type of machinary you just pay the price.

Keep us updated and let us now how it goes.

 

[omnicron]

I dont know in your town but here theres places with all type of machinary you just pay the price.

Keep us updated and let us now how it goes.

No place like that here that I ever heard of. It not like there...people here are greedy or afraid of getting sued if you was to get hurt.

 

[Timberdoodle]

omnicron- before spending a ton on a completely new setup, I would give your jet the most attention first because it will drive the sizing of all the other components in the system. An efficient jet will reduce the pump volume requirements dramatically and possibly enough to use your existing pump and dredge to run a 5" hose instead of a 6". The increase in hose area from 4-5" is only a 56% increase and since the dredge is designed for a total volume of throughput this may save big bucks while still providing more material movement.

ie.. 4" dredge using log jet - jet has approx. 1-1 ratio of suction to supply (250gpm draw = 500gpm total volume to box)
A 5" efficient jet could render ratio's in the range of 3 or 4-1. so it is possible to run a 5" jet from a pump that can deliver 120gpm at 30psi which would result in 360gpm suction draw in the hose and a total volume to the dredge of the same 500gpm range. Only updates to your system would be flare, jet, and hose.

The main point is that a more efficient jet can reduce the total volume to the box and pump requirements so you don't want to buy or build the system based on the standard sizes used for most equipment using a standard log jet if you are going to build a jet and want to save some bucks.

 

[omnicron]

omnicron- before spending a ton on a completely new setup, I would give your jet the most attention first because it will drive the sizing of all the other components in the system. An efficient jet will reduce the pump volume requirements dramatically and possibly enough to use your existing pump and dredge to run a 5" hose instead of a 6". The increase in hose area from 4-5" is only a 56% increase and since the dredge is designed for a total volume of throughput this may save big bucks while still providing more material movement.

ie.. 4" dredge using log jet - jet has approx. 1-1 ratio of suction to supply (250gpm draw = 500gpm total volume to box)


A 5" efficient jet could render ratio's in the range of 3 or 4-1. so it is possible to run a 5" jet from a pump that can deliver 120gpm at 30psi which would result in 360gpm suction draw in the hose and a total volume to the dredge of the same 500gpm range. Only updates to your system would be flare, jet, and hose.

The main point is that a more efficient jet can reduce the total volume to the box and pump requirements so you don't want to buy or build the system based on the standard sizes used for most equipment using a standard log jet if you are going to build a jet and want to save some bucks.

Good info but a few questions. How could a dredge sluice handle the higher feed of material without having to slow down the feed rate? As it is, I have to watch the material so I don't suck up to much and overload the system.

 

[Timberdoodle]

Good observation. The water/material ratio's are going to change some and would require management, but probably no different than running a 6" with an infinity jet as far as learning the best feed rate. The benefit of this approach would simply be less manual material handling which is a major factor in efficiency and less costs by using existing box, floats, pumps etc..

 

[omnicron]

I'm going to chew on this idea for some time, I still have a few month to go before I can get back in the water...In theory using a infinity jet could I not be able to also get say a 10 to 15 hp engine and around a 500gpm pump or something along this line and still put together a larger dredge?

From my perspective while dredging, most of the cobbles I have to move by hand fall under the 5" size. If I was to keep my current setup, I would still have to move these bigger 3.5"+ cobbles still, slowing down production. Moving material is the name of the game when it come to dredging as you know, there has o be a happy medium somewhere. This is going to be my regular real job this up coming year and I want to make sure that I have everything in place to start so halfway I'm not back tracking. I need to turn a profit as soon as possible, my goal this year was 3 grams a day and my goal this next season is 6 grams a day. I know that's a tall order, I might have to spend days or weeks finding a pay streak but I want the "equipment factor" removed from the equation. Being cost effective during this build would be ideal situation but I don't want to take half measures if you know what I mean.

If I do the infinity or your octajet with the above engine/pump. would I still be able to dredge down 20ish foot with good suction? I've identified the Palouse River as a potential prospect and from what I understand, the overburden can be quite deep.

 

[Oakview2]

If the state allows the use of a six inch, and its in your budget, on good ground you will beat that six grams a day easy.

 

[omnicron]

If the state allows the use of a six inch, and its in your budget, on good ground you will beat that six grams a day easy.

Oak, the regs in Idaho is no more then 15hp and nozzle size of 5" so I was going with 6" and restrict it down to 5". In some of the other states I'm considering moving to, they have different regs but it seems that most are limited to 4"...in that case I would just restrict my nozzle down to 4" and deal with having to move more cobbles. The one state I'm confused with is Colorado, seems that there is no set nozzle limit, just how much area you are allowed to move in a year or something... Still trying to get that all researched.

Is it true that a 6" dredge can turn low paying ground into paying ground?

 

[Timberdoodle]

I've never personally dredged below 12ft or used anything over 4" and do not have the experience to judge the needed additional suction to lift this high, but it has been my experience that each additional 10ft length of suction hose can reduce suction by approx. 1/3rd. Add to this the hose velocity required to lift a 5.5" cobble 20ft high and you will need some good suction to work at these depths. If it can be accomplished with a log jet than it can certainly be accomplished with a infinity or multijet using less hp and water. Whether you choose to go 5" or 6" a more efficient jet will help with the additional depth.

From what I have read, a 6" dredge pretty much requires a 2 person crew for both operation and transport. Hopefully others can give some advise on this. If you converted the 4" dredge to a 5", you would still have similar operation and portability of the 4". In the end which ever decision works best for you goals and operational needs is the one to go with.

 

[omnicron]

Thanks! A 6" can be ran by a single person, it's just going to slow down production but I have a high energy level and motivation so I should be able to compensate to a degree
Packing the dredge to the water will be a issue but that's were modular designs come in so all I'll need to do is make several trips back and forth with pieces, thats what I do with my 4" any way...I could end up building a cart of sorts or add wheels to the dredge to help out. One of the areas I want to dredge this year on the South Fork Payette is a canyon with no access other then from up/down stream (I'm hoping on good untouched ground). I'm considering my options from floating it down river and camping riverside to a zip line...the problem with floating it down river is the class 3+ rapids and using a zip line with one person has it's own problems lol.

Timer, it sounds like I might just go with a 13hp engine from Harbor Freight and this pump DP500 Pump -- Dahlke Dredge It looks like it doesn't require a threaded shaft. Just hope the pump will be sufficient to meet my future requirements otherwise I'll wish I had gone with a 750gpm pump!

 

[Oakview2]

Hoser would be the one to tell you the real difference, but Keenes site says under optimal conditions,14 yds per hour. That is over 9 yds per hour more than the 4". If you can run twice as much yardage, twice as much gold and with it reostricted to 5 inch, lots of suction and fewer plugs. Can't wait to see the new rig and results.

 

[omnicron]

Hopefully Hoser will throw his knowledge into the mix here.
Oak we all know that keenes numbers are based on sucking sand, their (ideal circumstances) and real world is much less but I understand what your getting at... a 5" will run double what a 4" will and a 6" will run double what a 5" will or something like that...Either way I'll be moving lots of material...
Damn I wish it was that time already start building/buying and getting ready!