Properties of punch plate (or Jarvine Riffle) for improving gold capture

[PickAxeCA]

There are plenty of people (Doc from Gold Hog, Vo Gus, etc) who claim that the majority of their gold is caught in the pooling area where water falls into the top end of a highbanker. I have heard some claims of 80-90%+ being caught up there.

With this in mind, what are all the magical properties of a *small section* of punch plate over miner's moss (backed, or unbacked with V matting underneath) that cause such strong gold capture in the area with falling flow?

Here are my thoughts:

1. Friction - coarse gold gets snared in the moss (this is obvious)
2. Additional classification (also obvious)
3. Downward hydraulic pressure - 'pins' gold to the bottom, forcing it to burrow down even further.
4. One way ticket - once gold has sunk under the punch plate, the non-perforated parts (solid sheet) is a vertical barrier. Plus, water falling through holes will not let the gold rise upward again.
5. Reduces water and material speed
6. Diffuses flow - spreads out water, creates a more even flow, reduces surging, reduces turbulence and lifting force
7. Breaks surface tension - gold cannot rise up to ride on the surface tension
8. Creates a fluid bed (elutriation / gravity column) - if a reverse ramp riffle is used on the downstream end

----

What are your thoughts on punch plate or a diffuser at the top of a highbanker or sluice, and its impact on capture rates?

Are there any magical gold-catching properties that I have missed?

Let's talk about all the uses for punch plate when it comes to sluicing / highbanking.

Note - I'm sure many of you have heard about the Jarvie / Jarvine riffle (punch plate folded like an accordion). I wonder if it has unique properties that make it more effective than normal punch plate for capturing gold.

 

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[Assembler]

There are plenty of people (Doc from Gold Hog, Vo Gus, etc) who claim that the majority of their gold is caught in the pooling area where water falls into the top end of a highbanker. I have heard some claims of 80-90%+ being caught up there.

With this in mind, what are all the magical properties of a *small section* of punch plate over miner's moss (backed, or unbacked with V matting underneath) that cause such strong gold capture in the area with falling flow?

Here are my thoughts:

1. Friction - coarse gold gets snared in the moss (this is obvious)
2. Additional classification (also obvious)
3. Downward hydraulic pressure - 'pins' gold to the bottom, forcing it to burrow down even further.
4. One way ticket - once gold has sunk under the punch plate, the non-perforated parts (solid sheet) is a vertical barrier. Plus, water falling through holes will not let the gold rise upward again.
5. Reduces water and material speed
6. Diffuses flow - spreads out water, creates a more even flow, reduces surging, reduces turbulence and lifting force
7. Breaks surface tension - gold cannot rise up to ride on the surface tension
8. Creates a fluid bed (elutriation / gravity column) - if a reverse ramp riffle is used on the downstream end

----

What are your thoughts on punch plate or a diffuser at the top of a highbanker or sluice, and its impact on capture rates?

Are there any magical gold-catching properties that I have missed?

Let's talk about all the uses for punch plate when it comes to sluicing / highbanking.

Note - I'm sure many of you have heard about the Jarvie / Jarvine riffle (punch plate folded like an accordion). I wonder if it has unique properties that make it more effective than normal punch plate for capturing gold.

Any thought about the size of the holes of the punch plate depending on what size of particles you are trying to catch?

Perhaps have different size holes for different drop out zones?

 

[Assembler]

3. Downward hydraulic pressure - 'pins' gold to the bottom, forcing it to burrow down even further.

Great point I love it. Thanks for posting PickAxeCA.

 

[Assembler]

Great point I love it. Thanks for posting PickAxeCA.

Come to think about it this is also true about the pressure dry as well..........hummmm.......I like it.

 

[ihatethese]

There are plenty of people (Doc from Gold Hog, Vo Gus, etc) who claim that the majority of their gold is caught in the pooling area where water falls into the top end of a highbanker. I have heard some claims of 80-90%+ being caught up there.

With this in mind, what are all the magical properties of a *small section* of punch plate over miner's moss (backed, or unbacked with V matting underneath) that cause such strong gold capture in the area with falling flow?

Here are my thoughts:

1. Friction - coarse gold gets snared in the moss (this is obvious)
2. Additional classification (also obvious)
3. Downward hydraulic pressure - 'pins' gold to the bottom, forcing it to burrow down even further.
4. One way ticket - once gold has sunk under the punch plate, the non-perforated parts (solid sheet) is a vertical barrier. Plus, water falling through holes will not let the gold rise upward again.
5. Reduces water and material speed
6. Diffuses flow - spreads out water, creates a more even flow, reduces surging, reduces turbulence and lifting force
7. Breaks surface tension - gold cannot rise up to ride on the surface tension
8. Creates a fluid bed (elutriation / gravity column) - if a reverse ramp riffle is used on the downstream end

----

What are your thoughts on punch plate or a diffuser at the top of a highbanker or sluice, and its impact on capture rates?

Are there any magical gold-catching properties that I have missed?

Let's talk about all the uses for punch plate when it comes to sluicing / highbanking.

Note - I'm sure many of you have heard about the Jarvie / Jarvine riffle (punch plate folded like an accordion). I wonder if it has unique properties that make it more effective than normal punch plate for capturing gold.

Essentially, in theory the Jarvis riffle acts better than regular punch plate, because it has more surface area in the same length, basically doubling the low and high pressure zones. This is supposed to slow down the gold and allow it to fall out quicker. I don't have a lifetime of expirence with it or other punch plate, but this next summer will have more of an opinion on it.

 

[Assembler]

Essentially, in theory the Jarvis riffle acts better than regular punch plate, because it has more surface area in the same length, basically doubling the low and high pressure zones. This is supposed to slow down the gold and allow it to fall out quicker. I don't have a lifetime of expirence with it or other punch plate, but this next summer will have more of an opinion on it.

I like the idea of #3 above about the Downward hydraulic pressure.

 

[PickAxeCA]

Any thought about the size of the holes of the punch plate depending on what size of particles you are trying to catch?

Perhaps have different size holes for different drop out zones?

Good point, if you follow the logic of the PopAndSon sluice which has 3 different sizes of expanded, perhaps you could have short sections at the top of each sluice or switchback with different sizes of punch plate.

Of course, that would be expensive, but I am assuing money is no object for the purposes of this thread.

 

[Assembler]

Good point, if you follow the logic of the PopAndSon sluice which has 3 different sizes of expanded, perhaps you could have short sections at the top of each sluice or switchback with different sizes of punch plate.

Of course, that would be expensive, but I am assuing money is no object for the purposes of this thread.

Well how much is your time worth if you save time and effort with the set up?

By PopandSon I take it is one after another or is it one above the other with the values falling through?

One could also expand as time goes on.

 

[PickAxeCA]

Great point I love it. Thanks for posting PickAxeCA.

I don't see downward or vertical hydraulic pressure being discussed much when it comes to gold capture. However, if you think about it, the flattest and thinnest gold is bascially a wing (as you already know).

I would imagine it's easier to pin a wing on the bottom of a sluice with vertical hydraulic pressure + gravity plus some way of diffusing water e.g. punch plate (just speculating, I have no sources to back up this claim).

A few thoughts:

1. Hopper capture: uses vertical hydraulic pressure (if the water shoots downward from spray bars or a hose). This gives maybe 20%+ of the fine gold, and a higher percentage of the coarse gold a place to settle, without needing to enter the sluice below.

2. Crash box capture: uses downward hydraulic pressure (moss, punch plate plus moss, jarvie riffle, or other diffuser) to catch 80%+ of gold (assuming no hopper capture).

Pretty much all gold sizes and shapes can benefit from vertical hydraulic pressure, enabling us to use the gold's shape against itself, by pinning it downward in a one way trap, so it can burrow down far enough to be out of the flow.

Assuming all of this is true, why is the default flow in a sluice box 100% horizontal? It might seem like a trivial question, but I wonder.

I've got to wonder if zig-zag, stair step, or step down style gravity concentrator might work just as well as a sluice, with significantly less sluice length required, since the vertical hydraulic pressure does most of the work.

Of course, classification would have to be to the right size to enable such system to work.

Or not, since the punch plate self-classifies anyway : )

 

[Assembler]

Good point, if you follow the logic of the PopAndSon sluice which has 3 different sizes of expanded, perhaps you could have short sections at the top of each sluice or switchback with different sizes of punch plate.

Of course, that would be expensive, but I am assuing money is no object for the purposes of this thread.

As far as expense goes try making the punch plate first out of plastic or aluminum to see how things work out.

 

[PickAxeCA]

Well how much is your time worth if you save time and effort with the set up?

By PopandSon I take it is one after another or is it one above the other with the values falling through?

One could also expand as time goes on.

I believe the PopAndSon system calls for 3/4", 1/2" and 3/16 expanded.

If you only have fine gold, you can probably omit the 3/4" and even the 1/2" and just go with 3/16" for optimal flour gold capture.

Gotta wonder if a cascading, stair step sluice with *multiple sizes punch plate* would perform well.

The new Gold Hog Z3 is a switchback sluice, with 3 sluices total in a Z configuration. According to Dan Hurd's video it has excellent capture of flour gold.

The switchbacks offer 3 different crash box areas, and each has vertical hydraulic pressure to pin gold down so it can burrow deeply into the mats.

Even better if the matting profile enables self-classification, so the capture surface isn't clogged up with large heavies.

 

[PickAxeCA]

As far as expense goes try making the punch plate first out of plastic or aluminum to see how things work out.

Good idea!

Additionally, I use a Dollar Store collander as quasi-punch plate in the hopper of my ultralight, ultra low volume, hard rock sluice (recirculating) that features the latest technology in hand-bailing of water, with a cut milk jug on a broom handle, and it runs on 1 gallon of water total, all day (I have to hike in the water, plus use 100 mesh nylon bags to clear out slime).

It's still faster than hand panning samples.

Here are some details of my hard rock sluice:

1. Accepts 1/2" or smaller classified material

2. Dollar store colander hopper, in a paint tray that has punch plate over V matting in the sloped area, plus moss over V matting in the paint well area.

3. The paint tray well has a small slot cut to enable water to escape. This area can act as a metered sluice flow gate, and a reservoir, to keep the water flow constant in the sluice below in between intermittent scoops of water.

Gold is pushed backward and downward via vertical hydraulic pressure by water coming down the sloped part of the paint tray. Plus, the water in the reservoir (paint tray well) is nearly always quite still, providing more settling time for gold. Gold also must climb up and out of the well, as it acts as fluid bed or elutriation process.

After the paint try, there is a short section of moss over V matting (another 'crash box') plus the rest of the sluice is all V matting.

The flow is very smooth and calm, with nearly no bubbles.

I'll be running some screened mine dump material through this system. We'll see how it does on hard rock gold ranging from -20 mesh all the way down to -200 mesh and beyond.

My point here is I try to use the following principles throughout this system:

1. Vertical hydraulic pressure (multiple locations) = gold burrows down
2. Diffusion (just enough flow to clear lights and most heavies, but not gold)
3. One way ticket (gold falls, in, and X% cannot escape)
3. Stop/start or reset (paint tray well)
3. Moderate flow, feed and angle
4. Self-classifying matting (V mat)

 

[Assembler]

I don't see downward or vertical hydraulic pressure being discussed much when it comes to gold capture. However, if you think about it, the flattest and thinnest gold is bascially a wing (as you already know).

I would imagine it's easier to pin a wing on the bottom of a sluice with vertical hydraulic pressure + gravity (just speculating, I have no sources to back up this claim).

This is the reason I love it as some will have a lot of flat shaped values in there area or if a hammer is used to liberate the values from the rock. Some will have the money and resources to add a set of rolls to roll flat the values before further wet process.

 

[Assembler]

Good idea!

Additionally, I use a Dollar Store collander as quasi-punch plate in the hopper of my ultralight, ultra low volume, hard rock sluice (recirculating) that features the latest technology in hand-bailing of water, with a cut milk jug on a broom handle, and it runs on 1 gallon of water total, all day (I have to hike in the water).

Hey it works right. Do you have a multi sand filter for you recirculating set up?
1 gallon is very low but saves the hiking weight.

The sluice length can be shorter however I like the idea of re-running as part of the classification step process and changing the punch plates or changing angles or both for your area materials.

I like the stair step setup in general however what ever works for you.

 

[PickAxeCA]

Hey it works right. Do you have a multi sand filter for you recirculating set up?
1 gallon is very low but saves the hiking weight.

The sluice length can be shorter however I like the idea of re-running as part of the classification step process and changing the punch plates or changing angles or both for your area materials.

I like the stair step setup in general however what ever works for you.

For sure. I'll look into sand filters. I just use a black mortar tub (Home Depot), with a small dish tub at the front to keep the meagre amount of water in a constrained space, so it can pool up a bit higher for scooping.

FYI - I have 2 bigger highbankers, plus 2 bilge pumps, batteries and a 1 inch Honda pump for proper placer highbanking.

I don't want to put junk water through my bilge pumps (at least not yet), hence the hand scooping for hard rock sluicing.

I will say, the jug on a 4 ft stick scoop works well, even for placer when classifying into a bucket! No need to bend down to grab water.

 

[Assembler]

Gold is pushed backward and downward via vertical hydraulic pressure by water coming down the sloped part of the paint tray. Plus, the water in the reservoir (paint tray well) is nearly always quite still, providing more settling time for gold. Gold also must climb up and out of the well, as it acts as fluid bed or elutriation process.

Are you using a sluice shaped like in the attachment photograph?
Thanks

 

[Assembler]

I would imagine it's easier to pin a wing on the bottom of a sluice with vertical hydraulic pressure + gravity plus some way of diffusing water e.g. punch plate (just speculating, I have no sources to back up this claim).

One pound per square inch (lbs/in2 or psi) is approximately equal to 2.31 feet of water height (column of water) no matter how big around or square the column is. One foot of water height is approximately equal to 0.434 psi. The centrifugal force in about 2 feet of water column should work well...........hummmm.......lol. The point #3 above is good with about one pound psi with 24'' or more. Heck with that much pressure there is going to be a lot of drop out............lol.

Elutriation is a process for separating particles based on their size, shape and density, using a stream of gas or liquid flowing in a direction usually opposite to the direction of sedimentation. This method is mainly used for particles smaller than 1 μm.

Elutriation is a process for separating lighter particles from heavier ones using a vertically-directed stream of gas or liquid. Elutriation is the separation of larger particles from smaller ones, using an upward flow of air against particles which are falling.

Elutriation is a well-established technique developed in 1948, which separates particles based upon size and sedimentation density, utilizing both centrifugal force and counter flow drag force........hummmm.......if there is a drag force at the pan surface should force anything flat to it. Wings will react quickly to a strong drag force.

The super pan can have a one foot water column as a finial setup process.
If the super pan is around 18" - 24" deep one can also have a good elutriation process step. Just thinking out loud here..........hummmm.........will have to incorporate as a second super pan......lol.

 

[ihatethese]

1. Friction - coarse gold gets snared in the moss (this is obvious)
2. Additional classification (also obvious)
3. Downward hydraulic pressure - 'pins' gold to the bottom, forcing it to burrow down even further.
4. One way ticket - once gold has sunk under the punch plate, the non-perforated parts (solid sheet) is a vertical barrier. Plus, water falling through holes will not let the gold rise upward again.
5. Reduces water and material speed
6. Diffuses flow - spreads out water, creates a more even flow, reduces surging, reduces turbulence and lifting force
7. Breaks surface tension - gold cannot rise up to ride on the surface tension
8. Creates a fluid bed (elutriation / gravity column) - if a reverse ramp riffle is used on the downstream

After taking a look at my Half-assed cleaned sluice in the garage, I think my final anwser is gonna be all of the above.
I don't want to sound like I'm bad mouthing the manufacturer but I feel like when they say "it doesn't clog" is a bit of an exaggeration, but it is specifically the fact that it does clog up why it works so well. Attached are the pictures of the Jarvi-riffles on my extension/expansion sluice. You'll knotice on the feed side the holes plug up, with even the smallest of particulates. However, that creates a vortex cavity on the other side of the riffle that remains clear. Additionally the shape of the riffles, or wave of the punchplate also acts as a nugget catch semi reminiscent of the bazooka everyone seems to be fond of.
Essentially, I think its better, and almost should be considered a must, over regular punch plate.
Note: My Jarvine riffle isn't store bought/home made its straight from Paul himself. I'm not affiliated in anyway with him other than my purchase.

 

[Assembler]

After taking a look at my Half-assed cleaned sluice in the garage, I think my final anwser is gonna be all of the above.
I don't want to sound like I'm bad mouthing the manufacturer but I feel like when they say "it doesn't clog" is a bit of an exaggeration, but it is specifically the fact that it does clog up why it works so well. Attached are the pictures of the Jarvi-riffles on my extension/expansion sluice. You'll knotice on the feed side the holes plug up, with even the smallest of particulates. However, that creates a vortex cavity on the other side of the riffle that remains clear. Additionally the shape of the riffles, or wave of the punchplate also acts as a nugget catch semi reminiscent of the bazooka everyone seems to be fond of.
Essentially, I think its better, and almost should be considered a must, over regular punch plate.
Note: My Jarvine riffle isn't store bought/home made its straight from Paul himself. I'm not affiliated in anyway with him other than my purchase.

Is the wave in the punch plate about 1/2" to 5/8" thick or high?
Interesting about the plugging on the feed side making a kind of semi wall on just that side.

Update looks like the product started with around a 1" wave then moved to around 1/2" wave now going to around 3/8" wave. This is not measured just eye balling the trend.

 

[Assembler]

Is the wave in the punch plate about 1/2" to 5/8" thick or high?
Interesting about the plugging on the feed side making a kind of semi wall on just that side.

Update looks like the product started with around a 1" wave then moved to around 1/2" wave now going to around 3/8" wave. This is not measured just eye balling the trend.

Why not have different wave sizes as you go down the sluice box?

If you have access to a metal breake should be able to make different wave size riffles to go down the sluice box.