Need advice - building a fluid bed sluice

[DukeArdelis]

Hi, I'm making a fluid bed sluice, you can see the pics of the current state below. I'm making it based on some plans I found here on the forum. I have altered the plans a bit, added a second trap, and a movable flap (or what ever you would call it, I'm not that good with English). It used to be an aluminum road sign.

My main concern right now is the size of the classifier holes. I'm trying to decide to make them 10 mm or 15 mm. I plan on further classifying the material. I'm new to prospecting, and I relay need advice on the subject, I think I covered everything else regarding the sluice, I will have other questions regarding the classifiers, fine gold ect.., but I will post them in new threads.

Thanks.

 

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[arizau]

First, the original bazooka gold trap has only one trap and it works perfectly fine. I'm not sure how a second trap would effect the performance but it probably will not help.

Second, if I were you and making the grizzly out of plate material I would try to fashion it as close to the original as possible eg. I would saw slits* in the plate rather than drill holes. That said, the plate is rigid and any rocks that get stuck in the slits, or holes if you decide to use them, will probably be harder to remove (the original bazooka uses spring steel so they flex a little making it easier to remove stuck rocks).

I also recommend that the tubes that go through the trap be removable/replaceable since you are probably going to have to experiment some with drilled hole placement and the opening sizes until you get it right.

Nice work on what you have done and good luck.

* A grizzly is usually made with parallel bars rather than with holes partially because there is more open area for sized material to pass through and they are easier to clear when they get jammed. Over size rocks ride the bar openings off the grizzly while, with holes they have a tendency to stop in the holes. I think the opening width is up to about 1/4" and perhaps others who own them will chime in with better info.

 

[DukeArdelis]

Thank you for your thoughts arizau.

As I was looking for plans and ideas to make a fluid bed sluice, I came across a guy who made a bazzoka like sluice with two traps, and he claimed that the second trap caught about 10-15 % in volume of the first trap. Since I'm making my sluice I decided to use all potentially good ideas. Also the "Aurora Mining - Expedition sluice" looks like it has two traps, and definitely has a plate with holes instead of grizzly's.

As for the tubes I planed to have them removable, I intended to keep them in place by mounting a bar over their front side, so they would be fixed between the wall of the second trap, and the bar outside the sluice.

I was thinking of grizzly's instead of a plate with holes, but when you search google for a "fluid bed sluice" you will see most fluid bed sluices have holes instead of grizzly's. Like this post on the forum here http://www.treasurenet.com/forums/s...ooka-mini-trap-sluice-plans-laser-cutter.html. Furthermore I have seen a lot of original bazookas that have been modified with mesh wire.

I do not plan on doing pre-classification, but rather classify my concentrated material at home, and than run it trough some finishing unit or pan it. This is because the closest gold bearing river is a few hours drive from where I live.

To be honest I have no clue what to expect, all that was ever found here is flour gold, but the equipment that was used did not allow for anything else to be recovered. I'm hoping to find some pickers, or even nugget's but my target is still the fine gold, and if possible a gem or two.

Since I have no prior experience in prospecting I would like hear some experiences of others using a fluid bed sluice.

 

[HardHatMatt]

The grizzlies on the Bazooka are smooth and rounded, which encourages the material to continue sliding down and out of the box. Cutting slits in a plate along the same axis the material will be moving should work better than punch plate, which just offers too many opportunities for resistance and snagging but neither is going to work as well as round rod. I would guess the DIY fluid beds you see use punch plate out of mere convenience; better to find a length of round rod and get to welding if you are going to do it right. In my experience using a Bazooka, anything that creates additional resistance is going to create more manual clearing of the grizzlies...and that's the whole point.

 

[Au dave]

I have a couple of homemade zooks and found them to work well. What I used for the grizzly was some birdcage wire, the spacing is about 10 mm. The larger zook has a baffle inside the trap that goes 1/2 way up the pipes ( originally for support ) and I have found that the back of the trap behind the baffle seems to hold larger gravels, not sure on gold ratio between front and back, but it catches all sizes of gold including flour.

Sent from my GT-I9305 using Tapatalk

 

[Vagadero]

My main concern right now is the size of the classifier holes. I'm trying to decide to make them 10 mm or 15 mm.

Well, what are the main dimesions of the sluice? Not all bazooka sluices have the same grizzlies.

Usually, smaller openings are better because:
-The trap needs less water volume.
-Better fine gold recovery rates.
The drawback is less processing capacity.

Here is a good solution how to make a grizzly. Except is better to hide or cover the lower end of the bars. Thus nothing will hang up there. I also made this mistake at first.

The double trap is indeed a good idea and improves the recovery rate. But it looks like 8-10" long in your sluice. That's too much.

 

[DukeArdelis]

And I had it all worked out in my head.

I understand now why grizzly's are better.

I will get some stainless steel bars, in the next few days.

I will have some trouble welding stainless steel, but I'm thinking of not welding it at all, but punting both ends trough hole's and fixating them.

Vagadero both traps are 15,5 cm long, or 6,1 inch.

I used a program called "Isiplot" to enlarge the DXF plans I found here on the forum, and if I remember correctly I doubled the size of the original, and that's how I got the trap size. When I added the second trap in the same size as the first, the sluice looked long and narrow, so I added 2 inches on both sides if I remember correctly, and thus the final size.

Why do think the traps are too big? Should I make them smaller somehow?

When I get the rods I will make a model of how I would do the grizzly's, and ask what you think.

I would like to say that I value everyone's opinion, and thank you all.

 

[goldenmojo]

Duke. Get some stainless rod and punch through and fold them over. Use one trap not two. The Aurora model has side vents and feed and your trap does not feed that way. The trap has to be feed the right amount of water flow and so has to be a certain size to work efficiently. Check the plans by Goodyguy and build it to what he has and you will have a sluice that works. If you build it to what you think will work you might be sorely disappointed or have to delude yourself into believing it is a great build. Good luck.

 

[DukeArdelis]

I did some testing in the last few hours with some steel rods, but not stainless steel, and I made a small grizzly just to see how it would be, and it seams good, I just need to get some stainless steel rods.

One thing is bothering me with this configuration, on the lower plate where I punch the holes for the rods i have small amount of free space around the rod, should I fill it with a filler?

Goldenmojo do you think that the size of the sluice is too big? It's about the same size as the " 36" bazooka miner ".

 

[arizau]

I think regular steel rod will work as well as stainless but it will rust. No big deal in my opinion but as the rust scales off then the diameter will change but significant change will take a while. Seal the holes. Actually I just sawed and filed mine down so they would fit flush to the deck so no holes.*

*I used aluminum rods for my grizzly.

 

[Vagadero]

And I had it all worked out in my head.

I understand now why grizzly's are better.

I will get some stainless steel bars, in the next few days.

I will have some trouble welding stainless steel, but I'm thinking of not welding it at all, but punting both ends trough hole's and fixating them.

Vagadero both traps are 15,5 cm long, or 6,1 inch.

I used a program called "Isiplot" to enlarge the DXF plans I found here on the forum, and if I remember correctly I doubled the size of the original, and that's how I got the trap size. When I added the second trap in the same size as the first, the sluice looked long and narrow, so I added 2 inches on both sides if I remember correctly, and thus the final size.

Why do think the traps are too big? Should I make them smaller somehow?

When I get the rods I will make a model of how I would do the grizzly's, and ask what you think.

I would like to say that I value everyone's opinion, and thank you all.

Just get a rebar or some nails. They are cheaper and less hassle.

So your trap is ~12" long in total. That's too long. You gonna need even more water than the original miner sluice.

 

[goldenmojo]

36" is good and the miner width is good. It will be very heavy to lift out of the water when it is full and you will need to have a tub to dump it im which is something extra to pack. The Bazooka prospector can be dumped into a large pan like a super sluice or a five gallon bucket and you will get two pan loads from the prospector sized trap. with a huge trap like Vagadero states you will need lots of water and extra tubes. I would start with a 30"-36" and not extremely fat. I have seen homemade ones ( I know of one built from scraps of aluminum and lots of rivets) that are somewhere near specs and they caught gold well enough. Stick as close to the original and you wont go wrong. Keep asking questions and reading all the build threads you can and then build one. Good luck

 

[goldenmojo]

Just looked at your build pics so far. Just use what you have for the first trap as you trap. It is about the right size. Make sure you mount a knock down basr on the underside of the deck on the inside of the trap nearest the grizzlies. With the aluminum frame you should drill through the front and pass your tubes through to the outside and either cap them or tie them to together to equalize the pressure. The only bad thing is if you smack the front of the box and the plastic tubes on something while you are out with it and crack them. Just remember the bigger the box the more water you need to run it. figure out how and where you will use it and build accordingly or just build lots of them. Good Luck.

 

[DukeArdelis]

I heard ya, and I'm making modifications.

1. I'll be using grizzly's instead of a plate with punched / drilled holes.

2. I'm removing the rear (originally first trap), and keeping the front (second trap in my design).

@ goldenmojo

I'm not from the U.S. or U.K. so I don't understand what you are saying in this sentence: " Make sure you mount a knock down basr on the underside of the deck on the inside of the trap nearest the grizzlies. ", I get the " underside of the deck on the inside of the trap nearest the grizzlies ", I know where you suggest I do something, I just don't understand what.




Now to configure the tubes:

I planed on using 3 x 1" inner diameter plastic tubes, the outer diameter is 32mm or 1 17/64 inch. On the picture below you can see a small cut of piece, the actual tubes are at a friends, he's welding the caps on, since he has a plastic tube welder.



Since everyone is talking about low pressure in the trap I was thinking of adding a funnel on the rear end of the pipes. The funnel on the intake is 3 5/8 inch wide, and that drops to 1 17/64 inch, I believe it should make some extra pressure. You can see the idea in the pics below:




Also should the pipes be closer to the wall of the trap, or longer toward the rear end of the sluice?

 

[goldenmojo]

No need for a funnel. The pressure of the water hitting the wall will force the water through the tubes. On the underside of the top deck inside the trap you need to mount a bar that goes sideways across the trap. When the gold goes through the Grizzlies it will run into or knock into this bar causing it it lose energy and sink or the disturbance from the water running into the bar will help it sink. The bar does not need to be very large maybe 3/4" at most and mounted close to the Grizzlies.

 

[Golden_Crab]

Just throwing this out there... you could make your tubes have a hose connect point with a ball valve + pressure gauge to precisely control flow to the fluid bed tubes and then have yourself a 20ft (or whatever length works in your area) hose to run an intake point in the most ideal location for how much water you require (less obviously for smaller material, more for bigger chunkier stuff or excess BS) and you can have a single intake funnel to help further in low flow situations.

Would cut a lot of the hassle / water issues out when using fluid bed systems in the current incarnation. At least that seems like the biggest frustration is finding the correct placement / water flow for these units to operate efficiently.

 

[DukeArdelis]

Thanks for all the help.

I understand now what you were saying, and to be honest I had not planed that, and I would most probably loose a lot of gold since it would get washed out.

I have one more question, should I place the middle plate (the biggest one where i drop the material) right to the wall of the trap or a little over? Please take a look at the picture below.



If sorry if I'm annoying asking all this questions, but wait until I get this project done, I'll have questions about classifiers, miller tables...

 

[DukeArdelis]

Hi Golden_Crab.

I just read your post, and it makes sense to me. I don't know if the outer intake would work without a pump, but perhaps it could be possible to attach valves to each pipe, and adjust the water flow as needed.

 

[Golden_Crab]

Hi Golden_Crab.

I just read your post, and it makes sense to me. I don't know if the outer intake would work without a pump, but perhaps it could be possible to attach valves to each pipe, and adjust the water flow as needed.

If you are at all familiar with the concept of gravity dredging, same principle for your water delivery. Long hose going up stream with enough drop can produce sufficient pressure / volume and just split when close to the sluice if you wanted a regulated pressure to your tubes without running 2 hoses. You could even gravity dredge with the setup if you thought it'd be productive with no modifications needed and had gold near the intake point!

 

[goldenmojo]

Duke. Yes run the deck all the way to the trap wall and seal it up from the inside/underside of the deck with siicone or some other sealant. You want the box to pressurize ( pressurization chamber) into the tubes and any gaps or internal leaks will take away from this pressure. Mount your tubes in the trap before you put your deck on. Seal around the tubes on both sides of the trap wall. Its getting there.