Micro Dredge?

[MacgyverMike]

I've searched, but beings as this is my second thread here, perhaps my search fu is weak...

Anyhow, I had an idea for a micro suction dredge since most of my prospecting outside the state of California is done via ultra light back packing. My concept is to run a 12V bilge pump off a LiPo jump pack to suck up fine sands. Nothing bigger than say 1/4". Since the supply would be 1/2", the suction nozzle would be about 1", so that leaves the question of the jet...1/8" or there abouts right? Considering my pump options are limited, what about using a needle valve to give me an adjustable jet? Or maybe brass compression fittings that I can swap out orifices with?

Sometimes I get back into places that are so remote, I'll likely never be there again, so why not process as much material as possible? Any other thoughts? Anybody done something similar?

 

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[arizau]

How about for a start and maybe some new ideas read this thread starting from the beginning. http://www.treasurenet.com/forums/d...ty-jet-submersible-gold-sucker-so-i-hope.html.

Good luck.

 

[Jason in Enid]

How about for a start and maybe some new ideas read this thread starting from the beginning. http://www.treasurenet.com/forums/d...ty-jet-submersible-gold-sucker-so-i-hope.html.

Good luck.

That thread is mainly a place to see what NOT to do, although it will show you ( if you can read between all the lines) that subbies are very difficult and more complex than a surface dredge, and that these 12V subbies are more about theory and testing than actual production. I have seen a LOT of people selling these abominations on fleabay over the years, and I've never read a good review from anyone who admits to buying one.

 

[winners58]

bilge pumps dont build pressure any restrictions equal less GPM
Build or buy a hand dredge

 

[MacgyverMike]

Thanks for the link. I'm shooting for the same concept, just a MUCH smaller scale...I have a hand dredge, I have a sniper tool, I'm just looking for a more efficient way to do the same thing. If I can fill a bucket in 5 minutes as opposed to 30, thats just that much more dirt to go thru.

Back in my younger days, I would hike out for days at a time, sometimes up to two weeks. I came across places that had the potential to be loaded, but limited to a trowel and a pan, there wasn't much I could do...and sadly, I probably couldn't find them again if I tried.

Now that I'm back at it, and this time with 3 kids, I'm just looking for a way to clean out a hotspot if I find one. The problem comes size and weight, and it adds up quick...

I'm a tinkerer, so I'll keep reading and learning and maybe put something together eventually. I'll be sure to update if and when I do.

 

[mendoAu]

Light weight and does a quick job on small deposits:
https://www.instructables.com/id/A-gas-powered-vacuum-cleaner-for-use-in-gold-prosp/

 

[Goldwasher]

Thanks for the link. I'm shooting for the same concept, just a MUCH smaller scale...I have a hand dredge, I have a sniper tool, I'm just looking for a more efficient way to do the same thing. If I can fill a bucket in 5 minutes as opposed to 30, thats just that much more dirt to go thru.

Back in my younger days, I would hike out for days at a time, sometimes up to two weeks. I came across places that had the potential to be loaded, but limited to a trowel and a pan, there wasn't much I could do...and sadly, I probably couldn't find them again if I tried.




Now that I'm back at it, and this time with 3 kids, I'm just looking for a way to clean out a hotspot if I find one. The problem comes size and weight, and it adds up quick...

I'm a tinkerer, so I'll keep reading and learning and maybe put something together eventually. I'll be sure to update if and when I do.

A 1" dredge running on a bilge is not the fastest way to move or process material.

 

[N-Lionberger]

Mini dredges are toys, you would be better off with a lightweight stream sluice.

 

[MacgyverMike]

Mini dredges are toys, you would be better off with a lightweight stream sluice.

I have one, an Angus Mackirk backpacker and a few other homebrew ones. The issue at hand is material collection. I can't process what I dont have. So even if its a "toy", if it fills my bucket faster than my hand dredge, or does the same job in a smaller package or with less labor, I'm ok with that...

I'm just picking brains to see what others have tried or learn about concepts I don't fully understand...maybe I can figure out something that works for me...

 

[Jason in Enid]

I have one, an Angus Mackirk backpacker and a few other homebrew ones. The issue at hand is material collection. I can't process what I dont have. So even if its a "toy", if it fills my bucket faster than my hand dredge, or does the same job in a smaller package or with less labor, I'm ok with that...

I'm just picking brains to see what others have tried or learn about concepts I don't fully understand...maybe I can figure out something that works for me...

But they dont work. You can fill buckets 100X faster with a shovel. The reason people move up into 3 or 4 inch dredges is because of the ability to process gravel. Everything that the dredge CANT move, YOU must move by hand. So when you try to use something that can only move sand, you spend 90% of your time hand-shoveling away the rocks. If you think you can work a spot that is only sand-size material, you can kiss the gold goodbye. The gold with be dropping out back where the bigger rocks are.

 

[MacgyverMike]

What I'm going for, you can't to it with a shovel. Maybe a spoon if you're lucky. Just this weekend, I was up in the Sierras, just over the NV side of the line in one of the little creeks. Found a decent crack in a slab, only 1 1/2" wide at the top, maybe 12-16" long and who knows how deep. I dug it out as best I could with a screwdriver, got enough for half a pan and this was the result.

 

[Jason in Enid]

What I'm going for, you can't to it with a shovel. Maybe a spoon if you're lucky. Just this weekend, I was up in the Sierras, just over the NV side of the line in one of the little creeks. Found a decent crack in a slab, only 1 1/2" wide at the top, maybe 12-16" long and who knows how deep. I dug it out as best I could with a screwdriver, got enough for half a pan and this was the result. View attachment 1763817

Oh, I see what you are trying to do. Have you looked at the hand-suckers (sorry if its been discussed already)? You could suck the cracks out and it all goes into a bucket for easy working later.

 

[MacgyverMike]

I've got several in multiple sizes. With the exception of my really small ones, they just aren't worth the weight...If its a purposeful prospecting trip, I take one, but on a 3 day 22 mile hike for a scouting event, no thanks.

 

[Goldwasher]

What your saying can't be done with out a hand dredge/mini dredge

I do all the time with out one..

Your not going to be able to make a mini dredge with a bilge That is gonna get you more material than going for the cracks that you can get to the bottom of.

Even a gas 1.5 inch dredge will only suck stuff from so deep in a crack it can't bottom out on.

The longer and smaller your suction hose is on any 12v motor you decide on is the weaker the suction.The bigger the pump..the higher the amp draw..the larger the battery.

Any hand dredge you have with a tip that can get into the crack is gonna have way more "power"

I would focus getting more material from other good cracks than worrying about whats at the bottom of ones that are hard to reach with unknown bottoms.

My bet is you can get more gold..from shallower cracks and not even in the water... than with a "micro dredge"

With a small light sluice and simple tools. That's what goes on long walks with me..

 

[arizau]

Maybe you can sleeve down a small hand dredge by using a combination of tubing....both surgical and semi or rigid drip tubing and be able to better clean some of those small cracks(?).

Good luck.

 

[MacgyverMike]

Good points, and some things I hadn't even considered. I got to poking around, and found some interesting options for "backpacking" hand dredges...and I've got a majority of the materials already on hand. Small, light, and efficient. We'll see how it goes. Unfortunately the doc has put the kabosh on any plans for the forseeable future. So lots of time for trial and error...

 

[N-Lionberger]

What kind of bedrock is it? Can you make the crack bigger?

 

[MacgyverMike]

What kind of bedrock is it? Can you make the crack bigger?

TBH, I don't really know. I'm pretty amatuer at this. Every place is different...and I go a lot of places (or at least I used to)...but I've encountered this situation on almost every trip, a small crevice, potentially jam packed, with not enough time or the right tools to get it all...this is a very niche circumstance for certain. I've learned a lot already just from the reading this thread has inspired, and its shifted my focus quite a bit. Hopefully I'll have an update in the near future...

 

[N-Lionberger]

I carry a hammer and chisel with me in my crevicing kit. Most of the bedrock I hit these days is this decomposing slate which I just scrape up with a pick.

 

[Dogbite]

I made this. It weighs 14 pounds. The 35Ah battery weighs 8 pounds and fits in back pack.