Home Build Dredge Input

[olga1913-Alaska]

Hello all,

Looking for some input from some fellow tinkers. I plan to post this on a couple of sites so please ignore it if you have seen it elsewhere. My partner and I are building a three inch dredge around a Honda 5.5 hp motor, Keene P180, and a Proline power jet. The rest of the materials have been cobbled together with what we could find here in Sitka.

The sluice is 14x60 with tapered sides from 9 inches at the head to 6 inches on the lower end. The local boatbuilding shop did it for us.

The stand is built from aluminum and is adjustable enough for us to use it with our home built highbanker as well.

The flare is a tapered aluminum box that is 30 inches long. It tapers from 5 inches to 14 inches. It is 9 inches high.

The punch plate is stainless and was cut out of a larger piece at a local gravel pit. It was beat to heck and we had to have a cement truck run over it a few times to get it close to useable. Heated and hammered out the rest. This stuff is impossible to find in town. Know it is heavy but it is all we had.

The entire length of the sluice is lined with black ribbed matting.

The miners moss starts under the first riffle and runs the 30 inches to the end of the sluice box.

The riffle insert is steel. Five riffles will be mounted on two inch side rails. The lower three riffles are one inch tall and we have one at a half inch and the upper riffle is at 3/8 inch. All are at 115 degrees.

The upper three riffles are covered by a 29 inch section of punch plate. The punch plate has a 3/8 hole pattern and sits 2 inches above the miners moss.

Please offer any suggestions for modifications. It is not done yet so any suggestions or comments will not hurt anyone’s feeling. (except for the welds....hehe) This has been a fun winter project and we are excited to put it to work.

Some questions rattling around our heads are:

Is the gap between the punch plate and the black matting too great at 2 inches?

How long should we trim the rubber dampener off the flare?

What range of degrees should we be able to adjust the flare to in relation to the sluice?

Are draw latches the best option to secure riffles in the sluice?

Thanks for reading this and thanks for responding with ideas,

Bruce

 

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[Jeffro]

Some questions rattling around our heads are:

Is the gap between the punch plate and the black matting too great at 2 inches?

Maybe. You won't know until you run it. I would say not, if it was a four or five inch dredge.

How long should we trim the rubber dampener off the flare?

Doesn't make much difference as long as you have a good foot or so in contact with the water. You could run it the full length if you wanted.

What range of degrees should we be able to adjust the flare to in relation to the sluice?

Doesn't need much adjustment. Make it adjustable from 10 degrees to 30 degrees (20 degree span) You'll want it to have a slight uphill so it won't be just your jets shooting out, which can happen. The tilt lets more water collect in the flare, and slows it down some. More tilt if you find it blowing streams of water down the box. The damper helps slow it down, too, so you may not need any adjustment after you find the optimum setting.

Are draw latches the best option to secure riffles in the sluice?
They're good if you have access to them. If you don't, you can run a piece of flatbar up from the lower end of the riffles (which you'd do anyways with latches) drill a hole in the end sticking up above the sides of the box. Next make a "hook" with a slot in it and mount it upside down on the side of the box. Now you can use rubber straps or tubing to secure it firmly. Thread it through the hole in the flatbar and knot both ends. Then slip one of the knotted ends in the slot on the "hook" and you're set.

Thanks for reading this and thanks for responding with ideas,

Bruce

You're welcome, and I hope this helps a little. You've got some playing around to do to get it fine tuned. Have fun!

 

[olga1913-Alaska]

Thanks for the input mrs.oroblanco and Jeffro. It is appreciated. Jeffro your comments for range of degrees has helped. We were planning to carve out an arch to allow us to adjust to any angle within a range. We will use your ideas for 10-30 degree range. Thanks. We will probably take the time to put in draw latches on the riffle insert. I have a couple left over from when we built our highbanker.

This is a suction dredge mrs.oroblanco. The fist picture in my post above was of a highbanker we had built a few years ago. For the first season our dredge will be mounted on a stand and not floats. Budget will not allow floats this year. We will not add a grizzly as it will be powered by a 3 inch proline power jet through a 3 inch suction tip. Had enough of the shovel. As plans have it now we will have to undo a coupling at the junction of the power jet and flare to get to any plugs. We are planning to avoid the quick attach couplers for fear of restricting the 3 inch I.D. anywhere in the system. Good advice on capping any rough hardware. This is the plan. I have left enough flesh on machinery to have learned that lesson. Thirty degrees, dishpan hands and jagged hardware do not mix. Thanks friends for your ideas,

Bruce

http://www.fmtravels03.com/

 

[Jeffro]

If ya get some good gold, send me a fillet.....

 

[Jeffro]

No grizzly with this one, a jet flare won't get that much lift. The punchplate at the upper end of the riffles takes care of sorting.

 

[Vodka1000]

Very nice dredge....
I have my own - 4 inch wide 4 feet long ( extra 3 feet ) could be attached.
No pumps just creek water and hard work.
Got some nuggets last year - how much are they anyway,

Derek

 

[Lynx equipment]

You should use woven wire instead of punch plate it has more holes . In my experience gold likes to skip across punch plate . Everything else sounds great. I like to have a double sluce top 3/8 bottom 1/8 I alwase use woven wire it slows the flow to clasifie better and if you do a multi stage sluce you'll catch more of the fine gold