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Setup Or Assemble Keene 5" Sluice Box?


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Steve - 

I know this is an old thread but i cant help but notice that the sluice on your 6 inch in these pictures looks a lot like a sluice i picked up with an old 5 inch dredge in Kentucky lol.    I havent been able to find out anything about this box on any of the other forums.  What can you tell me about it and do you have any pictures on how is is supposed to be set up right where the flare and sluice mate up.  

 

Any info and more pictures are appreciated!

 

Thank you,  

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Thanks Steve!  

I currently have the box pictured above which is 20"x72", and i also have a newer keene three stage box which is 20"x60".  Im trying to decide which box would be the best for my 5 inch river dredge build.  Weight is somewhat of a factor so i still have to figure out how to weigh both of the boxes to see which is lighter.  

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Oops.... got distracted and forgot about this - sorry!

I had to do a little digging. This is part of the 5" and 6" Keene dredge redesign that took place in the early 90's when they started upgrading all the old dredge designs. The main shift was from old "crash box" style header boxes to the newer flare style sluice boxes. I am guessing this sluice is from a 1992 - 1997 era Keene 5109 5" dredge.. The 5" and 6" Mini were the same dredge basically. The box is actually not very complicated, just a standard straight sluice with a flare jet attached.

This is from the Keene 1992 Spring catalog announcing the new dredge series. The sluice is listed in the specs as a SB-5N but I never recall ever seeing this part number. It is not shown under the sluice listing in 1992 and is listed as SB5F in later catalogs. SB-5N was probably a temporary part number or error. Most Keene part numbers are acronyms and so I can see it - Sluice Box (SB) 5" so SB-5 and then the N for "No Header". But final decision was SB5F "Sluice Box 5" Flared".

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Keene model 5109 5" suction gold dredge, from 1992 Spring Keene catalog

It looks to me like the upper end of your box has a piece missing (see tiny rivet holes). The upper end was enclosed with a hole cutout. The flare had an aluminum flange riveted around the upper end, and you inserted the flare from inside the box poking it into the hole cutout in the upper end. The flare pivoted loosely in the hole and basically just dumped into the upper box onto the large screen.

The rusty cross piece on your upper box used to have a long rubber damper attached that hung into and rode on top of the water coming out of the flare. The rubber was attached via an aluminum strip and some rivets.

I have tried to show that detail in these old photos from my collection...

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Notice where the flare meets the sluice....

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See flange end of flare in the cutout hole

The first riffle section had the square hole punch plate as a single drop in assembly. Very easy to take this sluice apart and clean up compared to the later "over/under" double decker design. This was the best dredge I ever owned when it came to adjustments, cleanup, etc.

The photo below shows the rubber damper.

sluice2.jpg

I may have some more photos and possibly parts diagrams. Your inquiry got me digging through my old document box which in turn has me posting catalogs and such to the downloads area of the website. Good project, thanks for getting me started, though a bit late! :smile: Anyway, I will dig everything out and get it organized and see what more I can find.

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  • 2 weeks later...

Use the 3 stage box, and on the side boxes use a good carpet all the way, this will trap the fine gold that is redirected that way...A good book on dredging will discuss the use of undercurrents, etc you want to use every trick to recover the fine gold which will be most of the gold that you will suck up...

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  • 2 months later...

alaskaseeker - 

When i said three stage i meant keenes newer over/under type sluice not the triple sluice with the side boxes.  Im still debating which would be the best to use.  

 

Steve - 

Thanks for the info!   I will figure out a way to make it work without the aluminum cutout/flange piece that is missing.  What are your thoughts on which box is better.  The older single stage that this thread is about or keenes newer three stage sluice pictured below.  Both weigh close to the same.  They will be used in a 5 inch dredge. 

 

I think im going to try and make a uber lightweight 5 inch by making an aluminum frame and using xps foam for the floats (i have a ton of it already).  Not sure if a 6.5 hp motor modded by putting on a performance exhaust, air intake and rejetting it, with a keene p180 pump would be enough to power a 5 inch.  

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I personally am not a fan of undercurrents. I am not saying they don’t work, but I never wanted the extra complexity and weight. And extra cons to cleanup. For me a well designed basic sluice box is preferable. That I because most of my operations were two weeks or less, and packing into canyons was my thing. Usually at freezing temperatures. Portability and simplicity mattered more to me than the extra few pennyweight of fines that might be captured in the short time frames. That’s just me though everyone calls there own shots on such things.

The sluice in my photo was a simple 6” straight run sluice and it was my favorite dredge I ever owned

If I was dredging months in a row then the best recovery possible would matter more to me, but that’s never going to happen now.

I did like the old side sluice arrangement for two reasons. Undercurrents are invisible in operations and can load up unawares. The side sluices you can see what’s going on and adjust. Plus, you can set the angle for the side sluices independently of the main sluice. Impossible for an undercurrent. Your only adjustment is to open or close the screen. But opening the screen not only adds more water but more fines, so it’s not a great way to adjust for things. Basically you just open it all the way up and cross your fingers.

Keene got away from the side sluice design because the whole assembly has to be on top of their floats. More lift, less power. The undercurrent design let the whole thing sit in between the floats at water level, giving more suction for less power.

The 6.5hp P180 will power a 5” subsurface dredge but is to weak for an above water sluice. It’s not impossible but I would want the sluice literally in the water, and a short hose, shallow depths. You could probably baby it along set up like that but it’s borderline for sure.

Numerous independent studies show submerged stationary screens as inefficient. Screens to be effective are above water, like in a high banker or trommel. This report was widely distributed in Alaska to help miners improve recovery systems since so many operation were losing a lot of gold. Clarkson Study

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Correct a 6.5 hp for a 5 inch dredge would be underpowered, but i wasnt sure if you were to add a performance exhaust, air intake and re-jet the carb to pull about 2 more hp out of it would it then power a 5 inch dredge ok.  Would the keene p180 pump become the limiting factor and not the hp of the motor?  

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