My G-pa gave me my first pan.
He also taught me how to use a sluice.
Never done any dredging.
Now, I've watched a lot of dredging action and have the idea, and understand how the thing works. Even been aboard one of the big dredges ( diggers, not suckers ) in the Sacramento Valley.
What I'm lookin' for, are the finer points.
Regulating water flow for material being run, for example.
Do you, or Can you regulate water flow?
Or does the flow remain constant, non adjustable?
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I noticed a metal ring that stands away from the suction inlet.
Is this to limit the size of material taken in and help prevent in-line clogging?
So, would, say a 3" dredge actually be a 2 1/2" as far as the ring size?
Oh ya, thinkin' 'bout a counter balance when using a longer sluice shoot.
Yeah, Steel Pan, I would'nt attach a pole to get deeper. the advantage of having two hands is one hand on the nozzle and I hold my other hand slightly in front of the nozzle to move the material and more important to move the bigger rocks out of the way so you don't get the pluggy pluggy. If you have a 3"dredge all of the rocks are 4inches. If you have a 4" dredge all of the rocks are 5 inches and so on. It is always best to be looking underwater to keep from getting plugged and blowing out your box. I would like to do the ball valve like Bill Flourchild said but you need to know if your pump will cavitate with the valve closed. Jeff one of the owners of Proline told me that their pumps were not designed to cavitate and by closing a valve you could burn up the seals on the pump. So make sure your pump can handle that instead of learning the hard way. Scott
Cavitation is bad, I was thinking along the lines of using a diverter type valve. This, to prevent "Blow out". I'm gettin' the idea that varing the engine speed and sluice angle is prob the best control for flow.
Yeah, Steel Pan, I would'nt attach a pole to get deeper. the advantage of having two hands is one hand on the nozzle and I hold my other hand slightly in front of the nozzle to move the material and more important to move the bigger rocks out of the way so you don't get the pluggy pluggy. If you have a 3"dredge all of the rocks are 4inches. If you have a 4" dredge all of the rocks are 5 inches and so on. It is always best to be looking underwater to keep from getting plugged and blowing out your box. I would like to do the ball valve like Bill Flourchild said but you need to know if your pump will cavitate with the valve closed. Jeff one of the owners of Proline told me that their pumps were not designed to cavitate and by closing a valve you could burn up the seals on the pump. So make sure your pump can handle that instead of learning the hard way. Scott
Scott is right try to keep the sluice as level just as long as the larger rocks are rolling off the end of the sluice but your riffles are not scoring out my problem with my 3" dredge was when I got a plug and knocked it loose the force of the water would blow out the whole box. to solve this I have a ball valve on the output of my pump and I can close it off then remove the plug the slowly open up the valve without blowing everything out of the box. I also have incorporated a over and under sluice this has improved my fine gold recovery dramatically.
Thanks for all the great info. Got More? Keep it commin'. Hey,......I'm learnin' here!!! ( lol )
I've heard of using a pole or rod atached to the end of the suction hose, in order to get to areas you can't reach without a snorkle or SCUBA. I figure that would be like shootin' in the dark, not being able to "see", just "Feel" your way around. I think the person is afraid of the water. LOL
I used to fresh water dive, though many years ago, I have no prob using diving gear. I may look into air systems for dredging. I wanna take a good look into dredging and equip.
I also have a Proline 3" combo. I throttle back a little from what proline tells me. You want to run at the flatest slope you can though without loading your riffles up , but sometimes you encounter area with tons of black sand. You can either clean up more often or increase the angle slightly. You might lose a little fine gold that way,but the proline riffles are designed to capture that gold. Also don't try to suck up too much material at one time. Keep a constant material feed through your hose. When I first started dredging I would think I'm going to suck as much material I can, what that did for me is get more rock jams and and also blow the fine gold out the back end.
yes you can regulate the flow. Some manufacturers like proline tell you to have a higher flow rate. Hubby and I always throttle ours down some anyway. You can chnage the angle of the box or should be able to. We have have a 3 inch combo and our box is 14x 48.
There are some good books and videos out too. Dave McCracken has the gold dredgers handbook and advanced dredging techniques part 1 and 2. Chuck lassiter from midwest prospecter has running the big dog. If you go to 49er mike or gpaa site and do a search for dredging you will get tons of info too.
Here is some paraphrased stuff from McCrakens book
You must have enough force of water to move the larger rocks off. Say a 6 inch must move a 5.5 inch rock. That is a pretty good flow of water.If your box loads up the finer gold will go out the end of the box or you can get so heavy you can sink or capsize your rig. So what looks like a heavy flow might be what the operater needs to move the bigger rocks. You just need to play with the flow you need.
In the book mccraken says that at production speed all the material except what gets trapped behind the riffles should pass out the end of the box without assistance from anyone. There will be an occasional big rock or so that need to be moved by hand.
Also the angle should keep the medium in a constant state of suspention so the riffle can concentrate the medium. But not so much there wont be a safe space for the material to hide (boiling out). Also you dont want the angle so shallow your riffles load up.
Mccraken says most dredges are pretty well set up at the factory.
Hope this helps some.
kathyc in ky
hope this helps
I have a small 2", it does have a adjustment for the sluice box but I have never had to change it.
I adjust the flow with the throttle on the pump motor. I do check my tailings and check in the sluice for activity with the fines. same as the sluice box, if it is loading up, I run alittle more water.
I found out with mine there is some flow difference if I use the suction nozzle or the power jet since mine has a crash box system (old dredge).
Flow seems to be about 1/2" to 1 " above the riffles (eddying)
Box size is 10"x 28". i think it would do better with a little longer box but the way it is it would tip too far forward on the floats if I change it.
hope this helps rick
Replies
Is this to limit the size of material taken in and help prevent in-line clogging?
So, would, say a 3" dredge actually be a 2 1/2" as far as the ring size?
Oh ya, thinkin' 'bout a counter balance when using a longer sluice shoot.
Cavitation is bad, I was thinking along the lines of using a diverter type valve. This, to prevent "Blow out". I'm gettin' the idea that varing the engine speed and sluice angle is prob the best control for flow.
This is an awesome site
How do you treat a "Gold-a-holic"?
You have him do recovery. LOL
Hey,......I'm learnin' here!!! ( lol )
I've heard of using a pole or rod atached to the end of the suction hose, in order to get to areas you can't reach without a snorkle or SCUBA. I figure that would be like shootin' in the dark, not being able to "see", just "Feel" your way around. I think the person is afraid of the water. LOL
I used to fresh water dive, though many years ago, I have no prob using diving gear. I may look into air systems for dredging. I wanna take a good look into dredging and equip.
There are some good books and videos out too. Dave McCracken has the gold dredgers handbook and advanced dredging techniques part 1 and 2. Chuck lassiter from midwest prospecter has running the big dog. If you go to 49er mike or gpaa site and do a search for dredging you will get tons of info too.
Here is some paraphrased stuff from McCrakens book
You must have enough force of water to move the larger rocks off. Say a 6 inch must move a 5.5 inch rock. That is a pretty good flow of water.If your box loads up the finer gold will go out the end of the box or you can get so heavy you can sink or capsize your rig. So what looks like a heavy flow might be what the operater needs to move the bigger rocks. You just need to play with the flow you need.
In the book mccraken says that at production speed all the material except what gets trapped behind the riffles should pass out the end of the box without assistance from anyone. There will be an occasional big rock or so that need to be moved by hand.
Also the angle should keep the medium in a constant state of suspention so the riffle can concentrate the medium. But not so much there wont be a safe space for the material to hide (boiling out). Also you dont want the angle so shallow your riffles load up.
Mccraken says most dredges are pretty well set up at the factory.
Hope this helps some.
kathyc in ky
hope this helps
I adjust the flow with the throttle on the pump motor. I do check my tailings and check in the sluice for activity with the fines. same as the sluice box, if it is loading up, I run alittle more water.
I found out with mine there is some flow difference if I use the suction nozzle or the power jet since mine has a crash box system (old dredge).
Flow seems to be about 1/2" to 1 " above the riffles (eddying)
Box size is 10"x 28". i think it would do better with a little longer box but the way it is it would tip too far forward on the floats if I change it.
hope this helps rick
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