Need Help/Advice On The Sluice Part Of My Dredge

[afreakofnature]

Hello Everyone,

I need some help on the last part of my dredge build. I am new to dredging, but obtained a lot of the parts and pieces along the way and had a pump already from my highbanker so most of this came together for free. I have a 2" Old Keene dredge that used to sit on an innertube similar to the one in the picture below (it now is on floats). Anyways lets just focus on the sluice, that is where I need help. I do not have any carpet, moss, punchplate or riffles. I did not get any of that when I got all this stuff basically given to me. I would like to know what to do to this and I am willing to spend some cash on the last bit. The sluice is 10.5" wide and 36" long. I do have Goldhog's Riverhog matting that is 30" long (untrimmed) that I was going to use in my highbanker, but chose not too. I see that they do use this in their dredge, but cut, with expanded metal near the top and some punch plate too I think, just based off the videos that I have seen. But their dredge is a 5" and their sluice is much longer, so I am not sure if their design would work for my little sluice, plus I have a crash box. So I need some advice on what to do. I have 36" of sluice length to work with, what should I do for the best overall recovery. I will be using a Keene's P90 Pump which produces a maxium of 100 gallons per minutes and capble of 161 feet of head lift. This pump works very well on my highbanker with various Gold Hog matting, but again it is a highbanker where the sluice angle can be tweaked, my drege only has 3 angle adjustments for the sluice. [FONT=Arial,Helvetica][SIZE=-1][/SIZE][/FONT]Please keep in mind that I can not test and test and test, like what is really needed. I am not able to dredge near home, I go out on trips to visit friends and relatives and will be using this in a variety of different places, like Oregon and Wyoming to name a few. Basically it is going to be a travel dredge. When it is all done, I will be sure to post some pics. Thanks in advance for all the help!

 

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[goldhog]

As long as you can get enough PITCH and get the water speed up, the riverhog will do well.
Trim the riffles on all of them much like we show on our vids.
Trim them very low, alternating a cut and throw riffle.
That mat will love water SPEED... and rocks will just roll down.
(Much like the video shows.)
Give it full power and water.
Under the header put 1/4" perf and you can run that perf a good ways down.
Say 12" or so.
Suspend the perf about 3/4" off the mats with bolts.
Where the mats are under the perf, trim the riffles almost even with the ramp.
Here's the video I'm talking about.
Doc

 

[omnicron]

Doc, is the perf metal needed? I'm considering ordering some for my 6" but I'm waiting for a bit of cash to finish it up.

OP, depending on the size of gold that your dredging, you don't need much of a riffle ie: if your gold is all fine then it wont take much of a riffle to catch it. You could use some 3/4" raised expanded and some ribbed carpet from a true value hardware store or home depot. Honestly you cant go wrong with the GH mat though if you can get the pitch needed.

 

[goldhog]

Doc, is the perf metal needed? I'm considering ordering some for my 6" but I'm waiting for a bit of cash to finish it up.

OP, depending on the size of gold that your dredging, you don't need much of a riffle ie: if your gold is all fine then it wont take much of a riffle to catch it. You could use some 3/4" raised expanded and some ribbed carpet from a true value hardware store or home depot. Honestly you cant go wrong with the GH mat though if you can get the pitch needed.

The issue with CRASH BOX dredges is that the larger rocks lose their inertia in the crash box.
This is pretty common on a crash box vs. a flare uppers. So... the perf metal helps keep things moving, while at the same time allowing gold to be trapped.
It's basically a highbanker on floats with a suction hose.
Also, it kind of acts like a slick plate but... you have the advantage of CATCHING gold..... rather than it just moving down.
This type of set up uses terminal velocity and is quite effective not just in dredges, but in highbankers as well.
It allows you to run without the concern of rock piles in your box.
Not so much an issue with a flare.
Doc

 

[Hoser John]

Classification,punchplate in the header, is the mother of recovery and them little ol'units sure need it. That looks like the antique(1970-82)kawasaki or the newer tanaka pump?? Both orange so hard to tell-no parts for either now. Looks to be in good shape. Leave it be,run and have some fun as not a serious tool but fun to mutz and putz. It has a header crash box with a good ol'suction nozzle so absolutely no connection to any highbanker ever made by keene as top and box all 100% different. The s/n is a good configuration for smallest gold so do NOT run full blast as then you'll just make a huge foaming slurry and float that gold right outta there. Slower,more level and WATCH OUT as them single tubbers love to roll over and go submarine on you and adios engine then-Enjoy your new toy-John

 

[afreakofnature]

John, that pic is similar to what i have for the sluice part. I used the pic as reference to my question. I will post a pic soon of my build.

 

[omnicron]

Personally I would use the GH mat, but keep in mind what Doc said, you need to be able to adjust pitch to get water speed. Without that you'll have great losses. The mats need water speed to be active.
It that wont work for you then you have several choices.
Build riffles
Get some 3 pound grating (excellent stuff) but its heavy and does catch gold like crazy
Use expanded metal but need to make sure you don't overfeed them.
Easiest solution would be to build in or add sluice adjustment for the GH mats. I heard something like you need like 2" per foot of adjustment.

 

[kazcoro]

The per foot is all dependent on how much water you put over the mats. IF you have it banked at 3" per foot with very little flow, you will not get active exchange. You want water to "sit" in the box while still flowing. That way, you will get the exchange. I worked an area yesterday with my highbanking dredge, and it was loaded with BS. You should have seen all the BS coming out of the end of the sluice. We got worried, and checked tailings. No gold. That is what we should see. Not trying to keep the BS, only the AU. I am only running about 2" per foot, but that will increase as I re-configure so that more water is running through the riffles, and not out the back of the header box. Just my thoughts on the GH mats and my particular configuration.

 

[afreakofnature]

I started a new post with my complete dredge build, so if needed we talk more than on just the mats or sluice configuration.
http://www.treasurenet.com/forums/d...4-my-first-dredge-build-lend-your-advice.html