Keene 3 stage sluice tuning

[Bonaro]

I have a Keene 5" dredge with the 3 stage sluice. I like it and I have been tweaking on it to improve efficientcy but I want to hear from others to see what they have been finding.
I have a lot of heavy black sands in the spot I dredge and the undersluice loads up badly. I run a steeper angle and the plate wide open but I am not satisfied. I have several other mods in mind but what have you guys done?

 

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[ratled]

Convert it to a Proline? I never could get those to run right enough to to keep one for any length of time. I keep running an old Keene O/U I coverted to a single stage. IF I knew that I was going to stay in one spot all season I would be running a triple.... and you know about those

ratled

 

[Oakview2]

We run in a very similar area, very heavy magnetized blacks sands, Keene 4 inch minin, Proline hp 400 pump, Honda 6.5. In a short run we would completely fill the box with black sands. Took all the riffles out but two, turned side ways, expanded metal welded to frame, over gold hog matting. Problem solved....

 

[russau]

Plus what kind of matting do you have on the lower sluice? any riffels? I run Veranda carpet with expanded over it on my lower sluice.i did pretty good on the Arkansa River in Colorado when I was out there.

 

[Hoser John]

Remove that insipid 3rd stage on top and convert to a simple over under and much less hastles,much better recovery, less weight for floats to handle,lower engine rpm and gas saving as not near the water required to run. Keep the discharge end out of the water as causes back pressure and slows the unders flow. John

 

[Jason in Enid]

Build a spacer block to raise the fixed head of the sluice up by several inches, then slide your box back to the front of it's adjustment. This gives you the same angle as now, but it brings your sluice up out of the water for better flow.

As for packing up with blacksands, if you have that much you will just have to do cleanups more often. You want to trap the heavies, but there is a fine line between trapping too much and losing the really fine gold.

 

[Hoser John]

Remove the top layer of screen as just a convalution and run that thang like a simple over under and you'll need MUCH less water and keep that discharge out of the water to increase underflow . Header style doesn't really matter. You want it like a ramp with the back end on the bottom and ramps up to cover the first set of riffles. The bent plate maintains the proper height over the first riffle and keeps any rocks from going back under to your under and they will. 2 sizes as smaller below and next size lets them little dwt nuggets be protected also in that first 6" and smaller riffle areas. The seperator plate can slide back and forth to adjust your flow to under. That little 4" has the semi flare header-longer throw to plastic so can be a smash with engine up and more angle or flare with a lowering of box and a slight slowing of the engine. Bi headers rock even on the huge ol'triple sluices as utilized on my 6" triple just fine-John

 

[Bonaro]

Plus what kind of matting do you have on the lower sluice? any riffels? I run Veranda carpet with expanded over it on my lower sluice.i did pretty good on the Arkansa River in Colorado when I was out there.

Russ, I am running miners moss in the first stage and in the undersluice. The rear over sluice just has veranda. I like the idea of gold hog mats.

The black sands are insane. I do daily cleanups but really should go to 2x day.

John, I know about the back pressure which is why in the pic I have the box as far back as I can with only a little dipped in the water. I like the head spacer idea (jason)

One of the things I am going to do is pull out the undersluice riffle tray and weld 3/8 tabs to the spacer rails. This will increase the gap between the upper and lower allowing more water flow. I will nee to reposition the upper riffle to do this. I also plant to place a line of cow magnets under the lip of the flare and clean those off often to try and pre-screen the BS out.

John, when you say remove the insipid 3rd stage on top are you talking about the first riffle set after the flare or the top riffle in back?

 

[russau]

Johns lower left picture shows the Veranda carpet. I use this carpet in my 4 inch dredge. John got it for me! I like it over the miners moss by far!

 

[LRC253]

In my 3-stage I have gold hog UR mats under the factory riffles in the first stage as well as the "under" stage. I'm running the same type of material as you and I have to be running about 3/4 throttle and the plate wide open to not get clogged up. I will be doing some more testing this season for losses. I dredged Waddell which has nothing but very fine stuff and did well for the short time I was there.

 

[specksandflecks]

I have a Keene 5" dredge with the 3 stage sluice. I like it and I have been tweaking on it to improve efficientcy but I want to hear from others to see what they have been finding.
I have a lot of heavy black sands in the spot I dredge and the undersluice loads up badly. I run a steeper angle and the plate wide open but I am not satisfied. I have several other mods in mind but what have you guys done?

Didn't you build a custom fiberglass flare for a Keene triple some years ago? I might be confusing you with someone else, it was long time ago on 49er mikes forums.

I have a 4" 3 stage similar to your setup. I tried a few mods and they seem to help, my changes were mostly trying to improve fine gold recovery though.

The very beginning of my under flow loads up somewhat with finer material from time to time. It can even pack the first riffle or 2, depending on how far up I set the under flow removable riffle. Once the riffles are under the lower part of the upper adjustable tray, they are fine. I've never seen it load up to the point where it becomes an obstruction to the underflow though.

I dono how big your gold is or if you have quartz float? but those riffles in what keene calls the 2nd stage are rather large and require a lot of energy.

Like Hoser always says having the under flow above the surface lets it draw more water. I have raised mine up a couple inches frame and all, and I run the flare as flat as possible until it hits the frame. I run my box a little too flat though so if you had a lot of heavies that could be a problem, but getting more water to the under flow should help.

I think some material build up at the beginning of the under flow is normal on these though.

You know it's kinda funny when you have made successful changes and your recovery improves, you start to realize how much gold you probably lost before.

**Loading up might be somewhat subjective term though. My highgrade section - that removable piece of aluminum with the v-mat glued to it- always has a layer of material on it. I see alot of people run so that section of bare v-mat is mostly scoured, as it would appear at the head of a hand sluice.

If I'm in decent material I can remove the v-mat plate and scrape the layer of material off it. Scraping parallel to the grooves so as not to disturb material down in the grooves, and the grooves will be filled with gold dust.

 

[Gelmac]

Didn't you build a custom fiberglass flare for a Keene triple some years ago? I might be confusing you with someone else, it was long time ago on 49er mikes forums.

I also wonder if this is the same Bonaro on the 49er mikes forum !

 

[Hoser John]

The wire mesh ramp that sits directly on top of the 1st stage upper riffles. So much fun tweaking to our own performance specs. Tons a au 2 u 2-John

 

[russau]

I also wonder if this is the same Bonaro on the 49er mikes forum !

Yep that's the same person! Dan had his triple for sale a few years back. flames and all! Im assumeing that it was sold!

 

[Bejay]

I would have to agree with John. Get the end out of the water....as the unit tends to have the "sluice tailing end" sagging down into the water....which slows the lower "flow" water dramatically. I created a way to do it. But no use explaining if you are going another route; as proposed in earlier posts. Sounds as if there are other ways to solve your problem.

Bejay

 

[Bonaro]

Yes, I was on 49er mike and I built the flamed out triple with custom flare. Sold it to a guy who was dredging on the Illinois in OR about 5-6 years ago. He sold it and I saw it pop up for sale on Armslist then lost track of it. I am guessing it's rusting behind a barn in Oregon and the owner has no idea what it's capable of doing. I miss that dredge...

I am gonna install that head spacer to raise the front of the box and I think I will try a smaller screen for the under. One thing I learned is don't make too many changes at once.

 

[Gelmac]

Glad to hear from you again, Dan. I remember your posts on the former 49er mike forum, miss that forum . Some of these great discussions over there is saved by the internet archive (archive.org) others were lost . Sad to hear your dredge is gone.

Agree too many changes at once make it difficult to decide which one has which effect on your setup.

 

[Gelmac]

Bonaro, would you mind sharing some of your posts -if you remember- that they were in the 49er mike? I am especially interested in your triple build. It could be of help to someone.

 

[Bonaro]

Bonaro, would you mind sharing some of your posts -if you remember- that they were in the 49er mike? I am especially interested in your triple build. It could be of help to someone.

Sorry, I went back to the archive on 49ermike.com and could not find the posts I made, that was almost 10 years ago...all I have now is pics.
Anyone with good fiberglass casting skills is already familiar with how to build this, all they they need is the design. It took considerable trial and error to develop this shape but it finally worked and worked well.
fyi - I have had quite a few people ask me to build one of these for their dredge. After I penciled it out I found it was FAR too time consuming to build them for hire unless I tooled up for some commercial grade molds.

 

[specksandflecks]

I was thinking that, after a project like that, tuning this new 3 stage should be a walk in the park. Now I'm thinking that the amount of heavies your into would probably give any recovery system fits.

Anyway thanks again to you and the others who shared their experience on the old forum. The discussions that happened there were invaluable to a lurking newbie.

Here is a short clip showing the simple lift kit I made for the 4" dredge. Rectangular alum tubing wasn't the ideal dimensions, but priced right as local rems.



If I did this over again I would lift it 3" instead of 2" though.