I built my own gold and sand separating underflow sluice box

[wild eyed willey]

Like the title says, I built my own version of the underflow sluice after watching the videos on youtube.
For the sluice body I used a piece of 5" X 5" plastic fence post from HD. ( it was 8 feet or 10 feet long so I cut a 3 foot piece ")
For the end I used a 5' X 5" post cap also from depot.
The pipe is 1.5" PVC ( there is a rubber flexible y fitting because the pump I have is too large for the sluice box, I divert some of the water back into the holding tank) I could buy a smaller pump, but I decided to use what I had on hand.

I drilled a hole in the end cap and used a male and female 1.5 " PVC fittings and some large rubber washer to connect the water inlet pipe to the end cap.

I used one 1 X 5" X 36" piece of pine board ( I drilled two 1.5 inch holes in the center of the board at the desired locations and then ripped the board in half long ways to create the u shapes. I then screwed the two pieces ( one on either side ) to the belly of the main body.

I covered the two boards with a piece of sheet metal, pressing the metal into the U shaped drill holes and screwed it flat the the frame boards.

The sheet metal I used was thin and white, so I spray painted it green ( like my gold pan) to help see the gold..

I used 4 metal L shaped brackets bolted to the main body so I could clamp the center flow blocks down tight and yet keep them height adjustable.

the flow blocks were 2 small plastic cutting boards I found at wallmart for $1.00

I took a spare piece of 1.5" PVC and ripped it almost in half to act as a guide to keep the base on the water tank.

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[jcazgoldchaser]

Looks great! Love the cheap walmart solutions.

Seems like you might need some sort of water diffuser on the input?

[russau]

well lets see how it works on fine gold! looks like youve had some sleepless nights thinking!

[wild eyed willey]

Will be cranking it up over the thanksgiving holiday. I'll let you know if it works.

[NeoTokyo]

Did it work well for you today?

[wild eyed willey]

As you can see there are two traps built into this contraption, it took some doing to get it set to where it would catch the majority of gold. The way it is now, it will catch most of the gold in the first trap, some flakes in the second, and at least 1 flake was pulled out of the tank. It does not wash all of the black sand away. If I set it up to remove all of the black sand, it flushes some of the finer gold out as well. I also discovered some small pellets along with the gold in both traps, some were magnetic and some not. I would say that it was basically a good machine, but you still have to pan out your traps. I think this thing would work well at the river where I could draw clean water, but the river is much too far away.. I may be able to refine the machine in some way, but as yet I have no idea what I would change.

[russau]

id rerun the cons with a lower water pressure or a less tilt on your sluice to see what got by you! you just cant beat seeing a peice of equipment that you built and its rewards!congrats!

[wild eyed willey]

id rerun the cons with a lower water pressure or a less tilt on your sluice to see what got by you! you just cant beat seeing a piece of equipment that you built and its rewards!congrats!

I am already running with very little water pressure, and the tilt is modest too. I even put several drops of Jet dry into the water. if I back off on anymore controls I will not blow out any sand. I really think I need fully adjustable flow stop plates, because I think just a fraction of an inch could make the difference. getting that kind of control might just make this thing work better. I also wish I could make the body out of clear plexi because it would help if I could see exactly what is going on inside the traps. Even painted green and with a light shinning from above I can't see whats going on unless I shut it down and look in once the water stops moving.

[Astrobouncer]

I think your answer to better recovery is going to be classifying the material smaller. With smaller material you wont need as much flow to blow out the gangue. But keep in mind no sluice gets 100%, there's always going to be a point where its better to run more material (yardage) then try for every little bit of recovery of sub 100 mesh. Classification is why the triple stage dredge sluices work so well for all sizes of gold.

[wild eyed willey]

I think your answer to better recovery is going to be classifying the material smaller. With smaller material you wont need as much flow to blow out the gangue. But keep in mind no sluice gets 100%, there's always going to be a point where its better to run more material (yardage) then try for every little bit of recovery of sub 100 mesh. Classification is why the triple stage dredge sluices work so well for all sizes of gold.

I'm only putting the last bit of black sand and gold flecks from the pan, the sluice box is supposed to clean the last of the black sand away. At least that was the idea.

[Davidail]

Wild eyed willey looks like we had the same idea, I build my small sluice out of the plastic fence post and also got it from H D I rip the post using my Table saw. Has 4" sides and is 48" Long I came up with the ripples which are 1/2" X 1/2" works really good catches all the Black sand and Flower gold without using carpet or miners moss. I am working on a bigger sluice now and just got the aluminum. bent It's 60" long and 8" wide I will be placing miners moss and my Black Ripples in it.

[Rebel73153]

David, where did you get the ridged matting for the plastic sluice?

[wild eyed willey]

I'm with rebel, where did you get the riffles?

[Davidail]

I made them, Made a form and Vacuum molded them, out of ABS sheet plastic. A friend of mine owns a Plastic Forming shop so I had some help and the use of his equipment I am Still experimenting and will have a new better design out shortly, right now I am working on a patient.for my new design. And the new one will be made out of Green ABS.

[Rebel73153]

Good for you. Sounds great.

[wild eyed willey]

From what I can see from the photo, it looks as though the gaps between the high points are too close together. You may want to space them out more so the gold can drop into them. Show us the new one when it's finished.

[wild eyed willey]

Weather permitting, over the weekend I plan on shooting a video of my separating underflow sluice in action. I added plexiglass windows to the traps so I can see what is happening while the water is moving. I think I will post the video on youtube and post a link to it here for you to see. I hope to be able to make this thing work well, but time will tell.