Confounding Sluice Problem

[omnicron]

It's just the second stage riffles that's having issues. If I increase the angle so the rocks will clear off, the riffles run clean...as in I can dredge up material and in 15 seconds there is only just a very little material behind the riffle. I'm sure I have enough water flow, the water level is around 2.5" above the top of the riffle. This last weekend I ran the box more flat and ran the engine at almost full throttle and the rocks did clear but so did the 1, 2, 3 stages of cons. At this point I am kind of pointing to gold hog mats...just need to decide which ones to get for stage 2 and 3. Hopefully Doc will chime back in on this thread.

 

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[goldgit'r]

Omni,I don't think you will be happy with the GH mats in a floating dredge that was not designed to run them.I tried them in a 2.5'' dredge and got them to work but had issues with the tail of the sluice being way under water and rocks not clearing.They work great in my highbanker but unless you are willing to really modify your dredge I would not get them.IMHO Wes

 

[omnicron]

I've already modified my dredge to be fully adjustable... Front to back and side to side so that's not a problem for me.

 

[goldgit'r]

If you can adjust it for 2'' per ft drop then go for it! Wes

 

[omnicron]

Yup can do that!

I made up another set of 4# grating riffles to put on the second stage and will put a piece of 3/8ths punch plate over that so that should stop my parking lot for rocks. I did leave 3 riffles at the end of the sluice just incase there is a magical nugget but for the most part the gold I'm getting the most of is -30. I'm almost done processing my cons from Tuesday and so far I'm at 3.1 grams for around 4 hours of dredging. I still have stage 2 and 3 to process and I'm hoping for another 1+ grams but stage 2 will have very little gold due to pile ups. Finally my wife is on board with my prospecting now that I'm recovering paying quantities of gold. I'm chasing the bedrock up hill towards exposed bedrock on a bend. I hope this pay streak goes to exposed bedrock and bend. That would be awesome...its another 15' away!

Thanks for every ones help, ideas and such!

 

[Goodyguy]

Your right, I was fortunate to be able to make a day trip today...I tried lower profile riffles on the first 3 riffles. All that did was cause the pile up at the end of the sluice now and I still had a few pile ups after the first few riffles. I think I'm going to make some medium profile riffles and then over lay 3/16ths rod spaced 1/2 to 5/8ths of a inch apart across the sluice, I think it should be ok sitting on top of the riffles. I think this will allow the rocks to pass freely while allowing the riffles to do their job. Anyone have thoughts on this>?

Also I want to hear from some pro's on their take on riffle spacing and design....John...Reed...Doc...Who ever else...

All advice so far is being considered, and I'm also considering gold hog mats but it's so damn expensive...

Definitely need the spacing, but make the space at least 1/8" more than the largest rock that fits through the punch plate.
The vortex mat is perfect for catching small gold, my advice is to keep it in place.

Here is the Heckler study on sluice box riffle design: http://www.hecklerfabrication.com/files/sluice-build-partIII-2.pdf
And the Clarkson study: http://www.hecklerfabrication.com/files/Clarkson_Riffle_Test.pdf

The physics remain the same whether the sluice is on a dredge or the end of a wash plant, highbanker, etc.
However, adjustments must be made per application.

Wish I could be there in person to help you fine tune your sluice for maximum recovery for your situation.
But seems you're on the right track.

Go for the Gold,
GG~

 

[omnicron]

Got it! Using the 4# grating was the trick with out punch plate. I tested my tailings many times every hour (few pans from different spots of the tailing pile) and didn't only have 1 small spec per pan! The best part was....my sluice only became a rock parking lot 2 times the whole weekend and that was caused by a flat rock I believe.

 

[goldhog]

Got it! Using the 4# grating was the trick with out punch plate. I tested my tailings many times every hour (few pans from different spots of the tailing pile) and didn't only have 1 small spec per pan! The best part was....my sluice only became a rock parking lot 2 times the whole weekend and that was caused by a flat rock I believe.

Love it when a plan comes together.
Good job.
Doc

 

[Goodyguy]

Got it! Using the 4# grating was the trick with out punch plate. I tested my tailings many times every hour (few pans from different spots of the tailing pile) and didn't only have 1 small spec per pan! The best part was....my sluice only became a rock parking lot 2 times the whole weekend and that was caused by a flat rock I believe.

Once you get the rock buildup problem under control and you want to catch nearly every single speck of gold that your sluice misses, try building a fluid bed "add a trap"

After it's installed you'll have piece of mind and 99.9% of all the missed gold.



With the vortex mat going the length of my sluice I seldom find more than a couple specks in the trap at the end of the day, but here in Indiana every speck counts.

* Note with the trap installed you may have to adjust the sluice back toward the motor a few inches to allow for the added weight of the trap when it's filled with water and black sand. (the overflow ports on the ends of the trap need to be above the waterline to function properly)
If you decide to build one, pm me for more details.

"Add a Trap" is held on by only two wingnuts and easily fits into a 5 gal bucket for clean out.


GG~

 

[omnicron]

Thanks to everyone who helped with advice and suggestions. Let me share a pic or two as this is the least I can do for everyone...
Such a beautiful thing... 7.6g in my AM Sidekick


Orgasmic...7.6g in my pan


So for 5 days dredging...3 of which I was losing gold my total take was about was almost 20g!!! I love it when things come together...I'm now going to have to support my family of 5 with a new baby on the way with my dredging till I can find a new job...I was let go yesterday for unknown reasons...got to love right to work states

 

[goldhog]

You da man....
Doc

 

[Jason in Enid]

If you can pull a few hundred a day dredging, you're doing good enough until a stable job comes along.

 

[omnicron]

I told that to my wife last night after she got home...she doesn't like the fact that I'll be gone 3-4 days a week. All I hope for is 3-4g a day...more would be better of course. I think now that everything is working good I can dredge 10 hours a day with only a few breaks to smoke (haven't figured out how to mount a cig to my hookah pump yet and have it self light every few hours ) Seriously, I'm so frigging pissed about being let go from work. I still have no idea why. I was completing jobs under time, was very through on DOT inspections, got along with co-workers for the most part and was always doing something. Maybe I wasn't screwing off enough and made the other guys look bad.... who knows. Maybe they don't like service connected disabled veterans... I was the only vet working there...hmmm.

 

[Oakview2]

Sorry to hear of the layoff, but it is great that your box is tuned up and you can still provide for your family

I told that to my wife last night after she got home...she doesn't like the fact that I'll be gone 3-4 days a week. All I hope for is 3-4g a day...more would be better of course. I think now that everything is working good I can dredge 10 hours a day with only a few breaks to smoke (haven't figured out how to mount a cig to my hookah pump yet and have it self light every few hours ) Seriously, I'm so frigging pissed about being let go from work. I still have no idea why. I was completing jobs under time, was very through on DOT inspections, got along with co-workers for the most part and was always doing something. Maybe I wasn't screwing off enough and made the other guys look bad.... who knows. Maybe they don't like service connected disabled veterans... I was the only vet working there...hmmm.