Tweaking the Triple

Bonaro

Hero Member
Aug 9, 2004
977
2,213
Olympia WA
Detector(s) used
Minelab Xterra 70, Minelab SD 2200d, 2.5", 3", 4"and several Keene 5" production dredges, Knelson Centrifuge, Gold screw automatic panner
Primary Interest:
Prospecting
I have a Keene 5" triple sluice dredge and I have never been able to tune it the way I want it to run. When I do a clean up, if I just shut down and open the sluice, the under riffles will be overloaded every time, no matter how I change the angles or damper opening. I know this is causing me to lose gold. I have fiddles with damper settings and sluice angles and nothing really helps.
I think I have worked out a solution, I need more water flow in the undersluice. The way it's constructed, only 1/2" of water is allowed over the riffles in the OEM design. I bought some 1/2" x 1/8" steel strap and welded it on edge to the existing rails.
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Don't laugh at my welding...my helmet has a goofy photo sensor and when I pull the trigger there is a long full second delay before the lens darkens and I get flashed really good, every time...result is I am welding pretty much blind. With this extra spacing I will now have about a full 1" of water over the riffles.
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Raising the damper above the lower riffles also caused the upper riffles to no longer fit. The eash fis was to simply drill new holes and remount it a little higher. However the square holes in the handle would no longer work with the latches. I didnt want to try and cut a square hole so I tacked on a couple small metal tabls and moved the riffles forward an inch.
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I now have a really good gap under there and it will flow a LOT more water. Testing to occur this summer, I will let you know.
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i have the same problems,especially when working with low drop /watervolume the undersection starts to clogg.When the watervolume is the problem it starts to clogg also with lights,though i have already a 1" gap in the undercurrent.Look at the box at 0.20 sec.in the vid.
Another factor is the 3/16punch plate that does not allow the water to enter the undercurrent with volume,then add that you are working a river with massive ammounts of heavies and the undercurrent will clogg.I think punch plate can work well in terms of waterspeed it creates in the undercurrent,if it,s built in a certain way and if you are working a river with low to normal black sands and have no high profile riffles in the undercurrent.Though it will always be inferior to wire mesh regarding screening capacity.Also the miners moss in the undercurrent is creating friction again.I use the moss in the open area riffles where the moss can work better with faster water.
If you have massive ammounts of heavies maybe hydraulic riffles a la bill in costa rica could be the way to go. In my river the predominant heavies is magnetite,(60 %)and i,m fantasizing about a demagnetizing trommel in the future that collects the black sands prior they enter the sluice in to a separat bucket for further processing later.That would save me so much clean up time ,energie.
For now i,m planing to replace the punch plate with wire mesh at the beginning of the screened area and raise the gap another half inch.Will test it in summer. Please let us know the higher gap worked out for you.

I,m preparing for a short trip now,unfortunately still to cold to dive,cheers
 

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My two stage that I built has 3/16 punch plate and in the lower I don't have riffles it has carpet and 1'' expanded steel with 1'' alluminium angle for the spacing between the two stages. My riffles are on the top section. try running your water a little faster I do seems to work good. Catches that fine NH. gold in the bottom and doesn't load up.
 

I have a Keene 5" triple sluice dredge and I have never been able to tune it the way I want it to run. When I do a clean up, if I just shut down and open the sluice, the under riffles will be overloaded every time, no matter how I change the angles or damper opening. I know this is causing me to lose gold. I have fiddles with damper settings and sluice angles and nothing really helps.
I think I have worked out a solution, I need more water flow in the undersluice. The way it's constructed, only 1/2" of water is allowed over the riffles in the OEM design.

That's always been the problem with their design, too much riffle and not enough water. That's why I started making mine out of 1" expanded and using a 3/4" opening over the riffles, this way it gives you the right flow for the small fine gold. Honestly, I would just pull the riffles and if you're in the area one of these days I have some extra expanded that would just needed to be cut to your size. I had a full 4'x 8' sheet at one time because it's great stuff. Also, you will find that you don't need miners moss under there because there's no where near enough flow to clean it out. Your better off with a good ribbed mat like the old stock Keene blue mat or the green works great also.
 

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