River sluice- internals

[MDH]

Well, head first into this I suppose, I've just got a bit keen and had a bit of sheet folded up for a river sluice. Bearing in mind that most places I try and give it a run will be in the slower/mid flow scenarios I've folded a 1200 piece of sheet to have an opening of 350mm down to an exit of 250mm. I wanted to do away with a flaired end thus eliminating having to fabricate and weld or join the aluminium but essentially create a gradual increase in flow via the tapering process(hope that works, as it made sence in my head but I'm a sluice virgin). Now I'm At the point of deciding on internals and research is quite conflicting, so thought I'd throw it out there and see if anyone wants to pitch in as to preffered internal workings for a sluice that's most likely presented in situations of slower flows and finer gold, (well that's all I've found at present). Bearing in mind the the external dimentions have already been folded so feel free to fire a negative comment on that if it sounds a bad design, all negatives can only be taken as a positive learning curve from where I stand right now, so if ya can help out with an opinion it would be great!!

Cheers, Matt

 

[elbowgrease]

Give the walbanker style bread crate and ultimat a go, if you can find a busted bread crate it won't cost you anything, the mat is about $30 from bunnings and the setup has well proven pedigree and dozens of forum members can vouch for how well it works, best of all its impossible to get wrong when compared to getting angles \ heights \ spacing of traditional style riffles and it works pretty good without needing huge amounts of flow in highbanker situations, so I would imagine it should work in a similar fashion with slow flows in the creek. Depending on how slow flow \ volume of water you

Given that you've got a fairly long box and one section of breadcrate is only somewhere around 600mm long you could even put a small section of expanded mesh before or after the bread crate.

Check out wal's walbanker sticky in the do-it-yourself projects section for pics.

350mm at the mouth is quite wide, espcially considering you said you are likely to be working in slower \ mid flow water so i'd make sure you leave plenty of "slick plate" at the start to help everything get moving before it gets to whatever internals you decided to go with.

At the end of the day there are heaps of options you can go for but if you want cheap, easy and proven the walbanker style is defintely a good place to start!

Cheers
Adam

 

[Guest]

Cant go past the bread crate, I ran a 2 days at eldorado with a bucket at the end of my Highbanker to catch losses only panned out 5 specks with over 12 hours of running. Would have easlily caught 99.99% and being fine flour gold thats amazing. Goodluck balx

 

[user 1769]

It's pretty well established that the bread crate works in a steep highbanker, but the question is does it work in a river sluice?

Anyone?

 

[Guest]

It's pretty well established that the bread crate works in a steep highbanker, but the question is does it work in a river sluice?

Anyone?

Wal has a video on it in a sluice, I have also ran it with a power sluice, And I run mine at a very low angle doesnt need to be steep. Cheers Balx

 

[Guest]

[video=480,360]http://youtu.be/r9JzXikgHN8[/video]

 

[Nugget]

I'm not sure if the bread crate is suitable for slow flowing streams as I thought it requires a fair bit of water to clear out, perhaps Wal might like to comment on this?

 

[Guest]

Make it a power sluice, will solve any flow issues.

 

[user 1769]

Balx, some of us don't have that option. Thanks for the suggestions though!

I have an AU Boss and it worked very well for me the other day on bugger-all water, once I channelled all the existing water into the sluice by using a plastic sheet-covered dam with a custom-built notch, and the correct angle.

 

[WalnLiz]

I'm not sure if the bread crate is suitable for slow flowing streams as I thought it requires a fair bit of water to clear out, perhaps Wal might like to comment on this?

Crate, and any vertical rifle system requires vortex's' to clear the gravel and this requires moderate to high water velocities. Slower streams or bankers with small pumps need to rely on what i call the "Drag" system to catch the gold.

I will go outside and take a few pics of my "slow water" variation trapping system and post it shortly.

Cheers Wal.

 

[WalnLiz]

"Low water speed sluicing and High Banking."

If you can't get enough water speed from a creek to create a vortex behind the riffle, then another option is to use what I refer to as the "drag system". You must have at least enough water speed and a reasonable length of slick plate to at least get the gravel flowing down the sluice.

In the pic above "A" being the slick plate should be approx half the length of the sluice, and flow directly into a section of sloped expanded mesh with no resistance from any matting or catch material. The sloped expanded will not sit flush with the sluice bottom and gravel will flow both under and over it....see "B".

Section "C" (short section of backed woven mesh), will only trap gold if the water speed is fast enough to clear the sluice.

What happens with the "drag system", is when gravel is fed into the sluice, the lightest material will wash down the quickest, followed by the black sand and the iron stones, leaving the gold to trail or "Drag" behind last, and slide under the expanded.

Depending on how much water speed is available will determine at which point of the sluice the gold will stop at. The gold will always slide under the expanded and stop at where the gravel begins to dam up through lack of water speed.

The gold will be sitting on the slick plate as the water speed won't be strong enough to lift the gold above the gravel, and it will eventually reach the point where there is no longer suspension. At low water speed the rest of the sluice may clog up, but the "drop out" zone of the gold will remain active.

Having a long section of expanded will give you a wider range of water speeds to work with. Let the damming of the gravel on the slick plate be your primary gold trap, and avoid any form of riffle system if you can't get enough water speed to create a vortex along the full length of the sluice.

Don't worry if the outlet end of the sluice becomes choked as the gold will have already fallen out much further up the box at the end of the suspension zone.

Upon clean out you will find all the gold just prior to the position where the iron stones and other heavies begin to choke the sluice. the gold will settle in this zone the same as it does when it gets swept along a bedrock stream.

The sluice shown is what I mainly use in a "Sapphire Only" stream, but the principal works the same on slow water pressure scenarios.

Cheers Wal.

 

[MDH]

Thanks guys, I might make both the crate and the drag style then and have them so I can interchange them in the short term. By the looks of that vid I'd say I have enough flow for a crate system if I help direct the flow at around half the spots I have in mind at the moment if that's the better way to go, and the slower flowing I'll try the drag system.

 

[MDH]

Well, I was finding it to find a decent piece of aluminium expanded for the "drag style" sluice system without paying a ridiculous amount for a full sheet but my little bro has just started a metal fab apprenticeship so he's gonna check out what's floating round the yard but said they don't do much al stuff so could be another dead end. In the mean time I decided to knock up the bread crate option minus the expanded, and now once pieced together it looks pretty bloody big!! Swinging a tape measure round in the air seemed so much smaller than it had become but what's done is done I suppose. I might take it somewhere for a run over the next couple days and see if I can get enough flow to clear gravel through it, but I'm thinking this design may get used a little less than the full length expanded design once I get my hands on some.

 

[WalnLiz]

The pic above will not lose you any gold with slow water speed....just keep looking for some sloped expanded and it doesn't need to be aluminium. It's extremely difficult to get hold of, and you're right in saying it's not cheap. Stick with Gal and you can't go wrong.

Cheers Wal.

 

[MDH]

Ok thanks Wal, how important is the expanded diameter for that system to perform best? I know where I can goes some smaller stuff pretty cheap, it's about 5mm thick and the actual mesh looked around 30-35mm, would that suffice or are you better off with the larger stuff like what's used on ramps and the like?

Here's the "bread crate" knock up, if I run this and there seems enough flow to clear it how detrimental would it be minus a piece of expanded at the front as per your vid? I'm thinking I may have made it a bit on the wide side now I've seen it together so if you can see any potential improvements feel free to fire away.

Cheers, Matt

 

[WalnLiz]

G'dat Matt,

You won't need any expanded with that length of sluice. You will however have to cut out all those squares and make "Ls" and rectangles out of them. You won't clear those squares with even high water pressures.

Cheers Wal

 

[MDH]

Thanks... I have cut it in a V pattern and left the squares inbetween, I shall cut the rest out then and give it a run and see how it goes.

 

[Cuckoowaif]

Hi Matty84 ,
How did you get on with your project ?
I am about to build the same thing , but I wonder how you got on with low water flows ?
Did you end up putting a flared entry on your sluice ?
Steve .

 

[MDH]

Hey, well when I initially tried it before I had sourced a good piece of expanded I had a small piece of very thin expanded and had a good location to set it up and it still caught gold in that small piece quite well, however I found almost all gold sitting in the expanded section. So with that in mind I've actually shortened the crate section and now it's roughly thirds between crate/mesh/slick plate. Being close to the triangle we've had a little of a dry situation until recently so it had been sitting there in completion without use until this week when I gave it a run but at the given location I had an ok flow but I could not get a sufficient drop for it to get the vortexes and clear the mesh properly, I could have if I carted my cons a few hundred meters but instead I just panned them. Since we're starting to get some creeks flowing now and had a lil bit more last night things are looking up and but many of the places I'm working (bare in mind I'm fairly new to the game and that's a limited list of productive places still!) have still only got puddles gathering so panning is my only option. In the next week or two I'll get it out for a good test. My brother folded up a carbon copy basically but with a slightly smaller mesh and were gonna run them close to eachother to see which of the two vortexes and clears better.

 

[MDH]

One will be run with expanded that's about 12mm high and the diamond part is about 90mm at its widest, the other is about 8mm by 40mm... In a nutshell it looks promising and I think it'll work superb in med/high flows but low flows are inconclusive. Hope that helps, otherwise you'll have to wait another week or so.

Matt