Bubbling sluice !! help or hinderence ???

[Mungoman]

Cavitation: When water flows over a dam spillway, the irregularities on the spillway surface will cause small areas of flow separation in a high speed flow, and, in these regions, the pressure will be lowered. If the flow velocities are high enough the pressure may fall to below the local vapor pressure of the water and vapor bubbles will form. When these are carried downstream into a high pressure region the bubbles collapse giving rise to high pressures and possible cavitation damage.

In other words, Aussiefarmer, the more bubbles you have in your race, the less pressure there is in your waterflow, allowing sediment or in your case, gold, to drop out of the flow and embed itself into your miners moss, or behind the riffles - It's all good - set your sluice at about 4 degrees or higher and don't worry about the bubbles - Good Luck and keep on shovelling.

 

[aussiefarmer]

8) That's zoomed in a bit I wish they were that big :lol: anyway the bubbles cant be to much worry as there is miniscule gold dust to small for my eyes to snuff up.

 

[aussiefarmer]

8) zoomed in a bit might be an understatement the pan would be 3 foot wide if that was scale :lol: :lol: I would say that is 3 to 4 times real life size

 

[Terrraaustralis2014]

The dream is to find something I can pick up and roll between my fingers .lol.

Mine is to find something I can't pick up and have to roll onto the back of a truck

 

[Goldrocs]

If you want my two cents worth get rid of the expanded meshes your riffles are not sitting on your mat they are being held up by the mesh which causes a fluid action under your riffles....
Cheers GR.....

 

[AtomRat]

Wtf... I must keep hitting the wrong button

As I phantom posted a day a go: seems you've done well there for the day mate throw a coin in the photo next time for size reference because it looks like you've found an ounce! :lol:

Mean lookin mesh setup

 

[aussiefarmer]

If you want my two cents worth get rid of the expanded meshes your riffles are not sitting on your mat they are being held up by the mesh which causes a fluid action under your riffles....
Cheers GR.....

Very interesting can we take a vote on this and get I few opinions , I will definitely give it a try, Two buckets of dirt out of same hole and run it each way.

 

[Tathradj]

I thought you had done this on a phone. LOL
Some times they make a mess.
It is a good post so I thought I would help things along.

Fixed your spelling mate.

Was that my spelling? Sorry.. phone has a slight delay. I try to proof read before I post but just get too excited Tathradj, I do.

 

[Jafnob]

How often do you do a clean up on this sluice?

 

[aussiefarmer]

How often do you do a clean up on this sluice?

I put about twenty ten liter buckets through it , so probably 1.5 hrs maybe 2 , It is still fairly clean when the flow is right and I don't feed it to quick the water is nearly clean by the time I reload it. I reckon it could do half that much again if not more but I don't push it as I have three matts for it.

 

[AtomRat]

I thought you had done this on a phone. LOL
Some times they make a mess.
It is a good post so I thought I would help things along.

Fixed your spelling mate.

Was that my spelling? Sorry.. phone has a slight delay. I try to proof read before I post but just get too excited Tathradj, I do.

I'm posting always via my phone and posting my threads / photos and vids and its very hard. I don't have a pc, thanks for the edits. I can't edit when my posts are too long so go ahead and fix em if you spot something

Hooe the sluice has been goin well farmer

 

[Ryan27]

You are worried about nothing! I suspect you have watched too many U Tube video,s like the LONG & BORING ones Mr Gold Hog Does.

For the most part the majority of sluices, high bankers etc will recover 90-95% of the gold specs in your material at an average daily production of around a gram loosing 5% is $2.50 and you keep $47.50.

What you should be worried about is finding a place to work that gives constant results.

The dream is to find something I can pick up and roll between my fingers .lol.

Dig deeper
Bubbles should assist with gold retention. When you oxygenate water it helps create zero buoyancy. Water has greater surface tension than air. The bubbles should help break the surface tension.
IMO go for volume and depth clean the bedrock and crevices if possible, that's where the course gold will hide

 

[aussiefarmer]

Dig deeper
Bubbles should assist with gold retention. When you oxygenate water it helps create zero buoyancy. Water has greater surface tension than air. The bubbles should help break the surface tension.
IMO go for volume and depth clean the bedrock and crevices if possible, that's where the course gold will hide

Your bubble theory is what I thought it has to be less dense than solid water
Where I have been looking true bedrock is deep , Found a good hard seam with larger rocks for that go , when I return to that spot and reopen my hole I will be concentrating on going down I reckon its about 4ft to bedrock maybe more.

 

[aussiefarmer]

Quick update, I made an extension for my sluice as I figured that would be the sure fire way to check 8) if gold was traveling to far down it.
I can clean the extension separately and haven't found a speck in it so the sluice is trapping the gold early.
I also added my versions of a gem catcher which also gives a different set of vortexes which I am really impressed with, you might also notice I have made it at a taper so the end is about 30 mm wider than the start which also reduces water speed and pressure.

Thanks to all for the feed back when I was unsure about my sluice and now I believe the bubbles are an asset and I run 400 liters of dirt through it and still had the bubbles.

 

[Ag Man]

If you want my two cents worth get rid of the expanded meshes your riffles are not sitting on your mat they are being held up by the mesh which causes a fluid action under your riffles....
Cheers GR.....

I was looking at my highbanker this morning & thinking the same thing...

Water going over the riffles causes the low pressure zone behind it, dropping the gold down.
Water going under the riffles can blow it out again.

 

[AtomRat]

I like it aussiefarmer! That's gotta pull gold..a lot! I like the lil gem catcher too. Have to tested it with high clay content material yet?

 

[Guest]

Cavitation {air bubbles} in your sluice? In my sluice, well the cavitation runs down a slick area then forms a line just before the riffle section and then rolls back on itself dropping any fine gold trapped in the bubble as it rolls.

As to running a section at the end of your sluice to catch gems I would recommend you google search Diamond sluicing & Diamond grease. You just never know what you will find.

 

[aussiefarmer]

Yep clay balls are fully dissolved before the get off the top layer if any do make it to the grizzly bars I just flick them back under the spray bars. Works a treat.

Most sapphires were caught before the final section but its good insurance and the fact I can clean it out separately lets me check if gold is down that far and so far all the gold has been retrieved from the first section with the riffles.
As for pulling lots of gold I can say it pulls everything I put in it, but that's not lots :| I think I need a richer patch as I only average about 0.4 grams for a day, it keeps me happy and its better than none I do like trying to find it off the beaten track which is probably why my average haul doesn't cover costs .

I just love washing rocks :lol: lmao. Might pilgrimage my way to Victoria sometime in the future and see if the grass is any greener.

 

[aussiefarmer]

heres the spray bars and grizzly setup 8) if I made it a little wider I would do the dishes in it ,clean anything it would also good to get the dirt out of your finger nails the smaller holes in the bars give good preasure jets.

 

[aussiefarmer]

Cavitation {air bubbles} in your sluice? In my sluice, well the cavitation runs down a slick area then forms a line just before the riffle section and then rolls back on itself dropping any fine gold trapped in the bubble as it rolls.

As to running a section at the end of your sluice to catch gems I would recommend you google search Diamond sluicing & Diamond grease. You just never know what you will find.

https://www.prospectingaustralia.com/forum/img/member-images/6236/1446335399_bubbles_copy.jpg

https://www.prospectingaustralia.com/forum/img/member-images/6236/1446334905_thumb.jpg

I have always wondered if I should have a slick section on the bottom run , that's why I extended it but I am convinced I am catching it all now, even gold dust . I will diffidently google that thanks the day you stop learning is the day you might as well lay in a box and wait for the worms :lol: