Reverse 3 stage sluice

[panningjack]

I'm rebuilding my Gold Divers 4" dredge. Many things to do but right now I just want to focus on the sluice. The dimensions are: 14" wide x 68" long
To start I will have vortex(rough top conveyor belt) running the entire length of the sluice. So do I keep it one continuos piece or is it ok to cut it into 2 pieces to help out with clean up?
This is a crash box sluice which I would like to keep since the place I dredge most often has a pay layer that sits right on top clay.















The 35" punch plate is a unique set up with 3/8" plate over 1/8" plate. The two plates start out touching each other and graduate to 1" apart at the end. This starts what I'm talking about with the reverse 3 stage sluice. Currently my problem is the last 6-8" under the punch plate backs up with material. I'm thinking of cutting off about 10" of the 1/8" plate and placing some expanded metal over hog moss for the next 10" to the beginning of the riffles. Thoughts?
Doing this would give me stage one: 25" of vortex processing -1/8" material. Then stage 2: expanded metal over hog moss processing -3/8" material. And stage 3: 1" riffles over hog moss processing the rest.
Because of the hassle of removing such a long screen deck to make a quick inspection. I will be adding a 6" piece of vortex at the very top of the sluice.

 

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[Hoser John]

Simple over/under is much easier and works much better. That don't look like a gold diver much?? Sure it ain't a Feldler??John

 

[omnicron]

Jack I found that one big piece was hard to work with (clean out) but it may be easier to deal with then trying to get 2 cut pieces to stay flat under riffles without having to fab some kind of hold down. Johns, Idea of a simple O/U is a great idea. I just love how mine last year catched the fine gold with the Vortex mat in the under flow section.

Dumb question, do you have any riffles that are un-screened? I ask because I wonder how you trap the elusive nuggets that are larger then 3/8!

 

[panningjack]

Simple over/under is much easier and works much better. That don't look like a gold diver much?? Sure it ain't a Feldler??John

I'm not 100% about the sluice. But the pump and couple jet I got with it are definitely gold divers

 

[panningjack]

Jack I found that one big piece was hard to work with (clean out) but it may be easier to deal with then trying to get 2 cut pieces to stay flat under riffles without having to fab some kind of hold down. Johns, Idea of a simple O/U is a great idea. I just love how mine last year catched the fine gold with the Vortex mat in the under flow section. Dumb question, do you have any riffles that are un-screened? I ask because I wonder how you trap the elusive nuggets that are larger then 3/8!

It is pretty hard to deal with a 68" piece. Think I will cut it down and just make sure I pin it down real good.

The last 33" of the sluice is unscreened 1" high riffles. They create a pretty good low pressure zone. Better than my old Keene mini 4. And the Keene riffles once caught me a 9 gram gold and quartz specimen, big as half my pinky.

An o/u sounds great for many places. A lot more fab than the current plan though. My spring/early summer spot has hardly any black sand to deal with and mostly coarse gold. The SF payette however has tons of black sand. A guy I was dredging by up there had a Keene 4" o/u 3 stage. He kept trying to trade and give me cash for my Keene 2 stage. He said because of the abundance of black sand his under section would clog up. Maybe he just had the wrong matting though

 

[omnicron]

It is pretty hard to deal with a 68" piece. Think I will cut it down and just make sure I pin it down real good.

The last 33" of the sluice is unscreened 1" high riffles. They create a pretty good low pressure zone. Better than my old Keene mini 4. And the Keene riffles once caught me a 9 gram gold and quartz specimen, big as half my pinky.

An o/u sounds great for many places. A lot more fab than the current plan though. My spring/early summer spot has hardly any black sand to deal with and mostly coarse gold. The SF payette however has tons of black sand. A guy I was dredging by up there had a Keene 4" o/u 3 stage. He kept trying to trade and give me cash for my Keene 2 stage. He said because of the abundance of black sand his under section would clog up. Maybe he just had the wrong matting though

Has to be a way to limit the black sand down there. Where I was dredging the bs layers were so thick you could see the layers and I would go 4 days before cleaning out my underflow section. Maybe I had more slope to the box they he did and that helped keep me clean. I had vortex matting and 3/4 alum expanded over that and was around 3 3/4" slope. After the 4 days when cleaning out you could just see the gold packed into the vortex matting and along the downward side of the raised expand. I need to get over and take a look at your equipment...I'm sure I'll learn a thing or two.

 

[panningjack]

Has to be a way to limit the black sand down there. Where I was dredging the bs layers were so thick you could see the layers and I would go 4 days before cleaning out my underflow section. Maybe I had more slope to the box they he did and that helped keep me clean. I had vortex matting and 3/4 alum expanded over that and was around 3 3/4" slope. After the 4 days when cleaning out you could just see the gold packed into the vortex matting and along the downward side of the raised expand. I need to get over and take a look at your equipment...I'm sure I'll learn a thing or two.

He had 1/2 raised expanded over carpet. I'm sure vortex makes a huge improvement. Maybe your 3/4 expanded keeps the material exchanging. Or maybe he wasn't steep enough. The amount of bs out on SF is insane though.

 

[Hoser John]

That's the problem with 3 ways as not enough velocity to clean properly. Convalution took a fairly decent dredge to a new and improved pain in the arse. Black sands no problem in a undercurrent when done properly. The amount of water(size of punchplate holes) is paramount to that particuliar problem. Think I have a pic of a 6 hour run,ran outta gas so a little white sands left but in a HUGE heavy black sand area and still clean-...John

 

[specksandflecks]

Currently my problem is the last 6-8" under the punch plate backs up with material. I'm thinking of cutting off about 10" of the 1/8" plate and placing some expanded metal over hog moss for the next 10" to the beginning of the riffles. Thoughts?

Difficult to say as only you have run that specific box in that area Under which punch plate does the material build up? Your planned solution might solve the problem, but if not what is your plan B, C, etc?

I like the Idea of using vortex mat, been wanting to try it myself. I understand why you put that strip of vortex in the high grade section, but is there a chance that will cause material to load up directly under it? Never used a chrashbox header so I'm not familiar with their effect on material at the head of the box. That said I wouldn't think it would cause much problem with the rest of the box though.

HJ's crashbox shows a damper, but I don't see one on yours. Something to consider if you haven't tried it yet.

Hard to tell how much room you have beneath the crashbox coupler. If there is room you could try adding a false bottom the same length as your screen. A little extra slope there could make the difference.

Anyway like I said hard to know whats best for your specific contraption situation. Then again figuring it all out is all part of the adventure I reckon.

 

[panningjack]

Difficult to say as only you have run that specific box in that area Under which punch plate does the material build up? Your planned solution might solve the problem, but if not what is your plan B, C, etc? I like the Idea of using vortex mat, been wanting to try it myself. I understand why you put that strip of vortex in the high grade section, but is there a chance that will cause material to load up directly under it? Never used a chrashbox header so I'm not familiar with their effect on material at the head of the box. That said I wouldn't think it would cause much problem with the rest of the box though. HJ's crashbox shows a damper, but I don't see one on yours. Something to consider if you haven't tried it yet. Hard to tell how much room you have beneath the crashbox coupler. If there is room you could try adding a false bottom the same length as your screen. A little extra slope there could make the difference. Anyway like I said hard to know whats best for your specific contraption situation. Then again figuring it all out is all part of the adventure I reckon.

Material builds up in front of the first riffle and backs up under the bottom (1/8") plate. I'm thinking the 1/8" plate just doesn't let enough water get to the first riffle. There's only about 2" between the end of the plate and the first riffle.

I do have a couple of metal wedges to hold that piece of mat down in the crash box area.
By damper do you mean a flap to spread the water and material out?

If my solution doesn't work out I'll probably build a normal over under box

 

[panningjack]

This is pretty much what I'm going to be doing with my sluice.

 

[omnicron]

Ahh you checked that out then. That's a cool system ehh?
I love the vortex matting in my under sections. When I do a clean up, its just all gold and bs in that section, but lots of it!

 

[panningjack]

Yeah, I found that trying to find something similar to what I was planning. The only difference will be where the shorter riffles are. Mine will sit in the bottom of the sluice. No false bottom