my first attempt at making a sluice need some advice

hi guys im after some advise on my sluice im making im a newby and havnt been prospecting at all yet .
sluice is 900mm long 280mm widemade from .5mm gal sheet metal.
under my riffels i have indoor outdoor blue matting which i think is what they call miners moss(it looks the same to me)

question 1 : on my pic i have an arrangement of riffels ( rubber matt , egg crete 10mm squares, ventalation grid (cut in half and joined to fit width of sluice), alliminium angle ( with " v " shape pointing down) and round alliminium bar, is this silly to have all these types or should i just settle with one of them?

question 2: is there a distance i should have between v shaped alluminium angle?

question 3 : the height of the riffels and matting are about 20mm from bottom of sluice, will this effect anything when the dirt hits a 20mm wall of the matting?

question 4 : will it work? i still have to make the flanged opening. to fit onto the front,

i hope im not asking to much of everybody for their time on giving me hints on what to do

thanks scott

Wal's D Man !!!! Ya want !!!

L/R

Hi Scott, I like you have had a crack at building a sluice, have a look at the tips I received from the brains trust on my post here https://www.prospectingaustralia.com/forum/viewtopic.php?id=1190 looking at the "v" riffles, you need to have the slope facing the water flow, kinda like this ( Water flow -->) (Riffle. /) ---> / -->/ ... the gap should be big enough to allow the movement of rocks to flow through the sluice between 45 and 15 seconds, if the water flow is impeeded too much it will fill up with gravels...

If you have more of the mesh material, I would use that along the whole length of the sluice or see if you can get your hands on some expanded metal or "walkway mesh" From what i have seen on utube and advice on the forum is that you need to get the material a consistent size so use a classifier or screen or some sort, 1/4 to 1/2 inch seems to work best for most.

Thats my 2 bobs worth, good luck with it.

I think you may have over done it a bit. From the looks of your riffles it will clog up.

Heres my understanding of gold and how to catch it. Basically all your trying to do is make everything in your sluice liquid sort of like floating that way the heavies sink first and thats when your moss or v matting can catch the gold. The idea of a riffle is to make an area of back pressure so the gold or heavies are sort of pushed up. If your riffles are too close or restrict the flow too much then it will clog up so the dirt is no longer floating and the gold will just keep running down.

G'day Scott,

Riffle section is way too over engineered. The section Tone outlined should answer most of your questions. If there's anything missing feel free to chuck some more questions out there mate. Most river sluices run on low water speed so moss and a sheet of expanded is all you need.

Take a quick look at my vid on how to build a Hi - Banker and that will give you some idea on trapping proportions.(just scale them down to suit a river sluice). Your egg crate left as is will fill with gravel and immediately clog. The section TONE is talking about shows my sampling box at the bottom of the thread. Keep the trapping section no more complicated than that. Hope this helps mate.

Cheers Wal.

The way I think of it is similar to the way air flows over a ute/truck cabin - the sudden drop of angle at the back of the cab creates a low pressure zone whilst driving at speed.
You can tuck most things there & they won't blow out, actually things from the back/middle of the tray get sucked forward to the back of the cab.

Quite often whilst driving, I'll put my apple core on the roof & watch it drop out behind the cabin rather than fly off the back.


With your sluice it's pretty well the same. gold drops out & gets sucked behind riffles at the right water speeds.

Too fast a water flow & everything will blow over & out the sluice.
Too slow a water flow & everything will drop in behind & in front of the riffles & clog up.

If your riffles are too close together then you'll just be making one big lot of turbulance with water going in all sorts of direction.

Keep it simple - we're just working with gravity.

Sounds a bit complicated but my advice is go out & see someone else sluicing & see what the riffles do & how the gravels behave when the sluice is running right.

With some fairly clear & smooth water flow, it's quite mesmerizing how the gravels/sands dance in the riffle section - exchanging heavy particles from lighter ones. All whilst there's no motors running - very peaceful...

Your on to something there ag man. I love the sound of rocks tumbling down an angus mackirk it sounds awesome.

thanks guys all the pieces i had were just samples of what i had around the house
ive been looking for the expanded mesh but it very hard to find, and when i do they tell me i need to but a whole sheet of it and was quoted $200 dollars. so ill just have to keep trying scrap metal places and metal work shops for an off cut.
all you guys make it sound so simple
thanks again.

Well Scotty, it is simple in theory, its the practical that makes it hard... find the right river, find the gold in the river, find the most gold in the river, etc etc.. not sure where you are in the world, but try metal fabricators, the places that make things like custom built tradesmans fitouts for utes and the like, most of these are made from aluminium saving on the weight and rust...

scottyalt said:

thanks guys all the pieces i had were just samples of what i had around the house
ive been looking for the expanded mesh but it very hard to find, and when i do they tell me i need to but a whole sheet of it and was quoted $200 dollars. so ill just have to keep trying scrap metal places and metal work shops for an off cut.
all you guys make it sound so simple
thanks again.

Click to expand...

G'day Scotty,

Catwalk mesh is too big for a river sluice. What you need is some ordinary (standard) expanded, Gal if possible, about 8mm high x 30mm wide.You should be able to get a small off cut from most engineering shops. If there's any scrap metal yards in your area they'll have plenty of various sizes. If you can't find some, then once you've made 10 posts send me a PM and i'll send some up to you.

Cheers Wal.

thanks wal you are top bloke i will keep looking aroundits a bit hard as i start tafe at 8 every day until 4:30 so bit hard to get around but im pretty sure i will track some down 'thanks again

Offers there anytime Scotty, that "tafe" can be a real inconvenience, but get it right and you could be driving a Porsche to the goldfields one day mate.

Cheers Wal.

it will be a long time before that happens wal.

putting some pics of the new and improved sluice, and im picking up some expanded metal tomorrow ive finally tracked some down.

im not sure if i should put any legs on the sluice so i can adjust the height as ive seen a you tube vid that says i need 1 inch drop for every foot of my sluice.any advise would be great.

i will load up a pic over the weekend of all the gear ive got hopefully someone can give me a hint if i may need something else,

Looking heaps better already Scotty, And good idea keeping that Guard Dog close bye.

You won't need any legs, as the stream will dictate the angle. Find the fastest flowing section close to where you're working.

Set your box up at a slight angle (don't bother measuring) so as to get the fastest flow possible over the riffles. Screen your material down to 1/4" and feed a small amount first to see what happens.

20% should stay in the vortex behind the riffles and 80% should flow over the back. If too much goes over the back, either lift the back of the box by placing a rock under it or place some larger rocks in front of the sluice to reduce water flow.

Hint: your better running faster water and keeping the moss/carpet visible, than running slower speed and not seeing the carpet.

Looking forward to seeing it with the mesh.

Cheers Wal,

thanks again wal your knowlage is priceless
all i need to do now is find a spot somewhere in nundle that is full of gold and i will be able to justify all this hard work to the wife. ive never been up there but might try near bowling club alley for a day as i can camp there then head up into the hanging rock to poke around the forest.
finaly got onto the computer to upload photos of my sluice finished and with all my extra tools that i think i need.
any more hints would be great

Sluice is looking great Scotty, and the expanded will make all the difference. The first 4 sloped riffles look great too, but i would take out every second one on that end section to keep the mat clearer. Best of luck on the stream mate and look forward to seeing the results.

Cheers Wal.

Thanks wall everything is made to pull out so I will do that and see how I go . The ute is packed and ready to go in the mourning, then to find s nice spot to sluice snd camp on the river
Have a grest weekend everyone

well its taken me ages to get into gear ive been panning madly every night after work and here are my pics of what i found in nundle over the long weekend.

i though i done ok for my first time and only a small hole.( the wife thinks im mad)
i also found some nice clear, red, orange and green stones. also found a metal that was very similar to gold but a bit darker and lighter in some pans, i was wondering what it was but then realised they were all round shaped and same sizes. then looked at my yabbie pump and could see the brass threaded rod had some pieces missing. i had a laugh to myself.


After talking to some other prospectors and them giving me some great info on how to pan i was into the creek. i only got one good mourning in i put 3 buckets through my sluice and brought a bucket home to pan. i worked on a little hole with my yabbie pump and slowly got deeper. i was putting the gravel through a sieve with 5 mm square holes and washing it with water into a 20 litre bucket. then putting it through the sluice. to my amazment when i got back from the sluice the dirty water had settled and i could see small flecks of gold laying around my hole.

a few passers buy dropped in at the same time and they were school teachers so i gave them some specs as they were looking for some gold but did not have any gear, the couple were geography teachers in newcastle and were over the moon to see the gold around my little hole and very suprised that i would give them some gold i also gave him some gravel to pan when he got home.
the hole got to arms length deep and i hit a good bit of bed rock witch was jaggered and was a natural big riffle under the layers of rocks and gravel, but it was time to pack up and head for home. i filled the hole so hopefully i might get back there this weekend.

in my clean up it took me ages to pan a 20 litre bucket of gravel, although it was so fun waiting to see what was in the pan at the end.
i started finding very small pieces but as i got through the bucket the gold got bigger and smaller pieces were no were to be seen.(they are not big bits but they are to me as it was my first time out prospecting).
in my process of panning i bought a rain water tank sieve from an pump shop this helped me get the bigger rocks out of my pan. to my surprise i found the 2 biggest bits of gold would not go through the sieve, thank god i was checking the sieve.
i also read about the blue bowl so i went to bunnings and got the parts and made one. i found little bits in the bowl but not as much as i was expecting. i think i need to screen to gravel smaller that my tank sive ( dont know thw size of the mesh but its like steel gauze for a window or door) as i still had alot of sand left in the bowl that would not go over the edge. not sure if water wasn't going quick enough around bolw but hose turned all the way on and its good pressure.

so this leads me to a few questions.

whats the best way to clean up at home? (blue bowl, small sluice , panning)

what size pump do you need for recirculating blue bowl set up?

how much sand/gravel to put in blue bowl at a time?

aslo attached are some pics of my sluice new and improved. added a handle to carry and handles to hold riffels down and pull out of the water.




might be back at nundle on saturday if anyone is keen.

looks like you have marine carpet in your photo

miners moss is the stuff below . you can get two types at bunnings , coarse gray and tight packed blue colour

I dont know which one performs better . i chose the gray but didnt trial it yet .



editted to correct speeling misteaks

Thanks heads up
Yeah i put a bit of marine carpet at the front to get the water to the riffle level . I had to get the water up as it was hitting a wall from my riffels and playing with my water flow . I have the blue indoor outdoor carpet from bunnings that you put in the picture under the expanded steel and riffles