Small Gold Dredge, Constructive Advice Needed?

[tvanwho]

I got tired of my almost completely homemade small dredge, constant floatation issues, got rid of my floation setup and sprang for 48 x 9 x9 factory dredge floats from DNK Prospecting in Oregon, but after they got here, I realized I needed a frame to make all the parts go together, as in engine,floats, sluice, etc..DNK had no frame unless custom built so I elected to try to build my own with 1/2 inch square steel tubing and rivets for now. I had to use 1/2 inch as nothing larger would fit where the frame attaches to the slots in the top of the pontoons.

I seem to have misplaced the aluminum caps I was sposed to use to hold the frame to the 6 mounting pads but had a sudden brainstorm. I really wanted a quick frame on/off setup so as not to have to mess with 36 sheet metal screws with the factory setup !! I got a 12 inch long drill bit from Menards and carefully drilled 1/4 inch holes thru the pontoon frame support ribs and made up some 1/4 inch diameter aluminum rods and pins. Now, I can remove the frame with just 4 pins and still have good frame support.

So, I need to know where to mount the engine/pump support platform? It is currently over top of the sluice header but still allows reasonable access to see whats on /under my punch plate. I will be using a Keene P90, 2.5 horse pump, 2 inch nozzle, and will point all the hoses out the back to avoid side to side weight issues when running my suction nozzle.

I was also told to make the sluice adjustable to get more pitch by sliding it forward if needed? So, I used 1 x 2 inch slotted aluminum angle to make this happen,welded to 2 subframe U shaped pieces and have a permanent 2.5 inch angle on the sluice for starters. I shortened the Keene Jet Tube as it was too long for the space available in my Subaru Forester. Now I can easily attach a quick coupler Keene custom made for me and just quick clip the hose to the dredge.

I'd like to have some carry handles or rails, any suggestions? I bought some 2 x 2 inch steel gusset triangles off Ebay to add support to the engine platform legs via welding. I am experimenting with no riffles this time, in favor of heavy duty raised expanded steel about 3/8 inch thick x 2 feet long with backed miners mosss underneath. I also raised the header 3/4 inch above the sluice box floor to try to get less turbulence,added some raised 1/4 inch hole punch plate and foot long section of Keene Miracle mat in the 1st 12 inches of the sluice as well, another experiment...

-Tom

 

[sjmpainter]

Hi Tom, Good call on the factory floats. After this next season you will be thinking " the best money I ever spent".

The 1/2 inch steel tube is plenty strong for a 2 inch setup. You would have been fine with aluminum. The rivets will wear out fast so you might want to have it welded or just use 1/4 inch bolts. Make sure you use nylock nuts on everything, the vibrations will loosen everything fast. And the most important thing, PAINT THE FRAME!

The mount for the motor is in a good spot as it is out of the way and with the size floats you have I don't think you will have any listing issues. Also if need be you can add some rocks at the other end to level things up As far as adjustment for the box, weld a 1/2 inch nut to each side of the box and use all thread with a T welded at the top. Forget about the sliding back and forth thing.

I really like what you have done with the 4lb expanded metal that should be really good on fine gold and the rainbow colored water softener is the bomb.

As a suggestion for handles I would get conduit and slip it into the 1/2 inch box steel use a conduit bender to make it wrap back to the next 1/2 inch box steel and pin it thru. This will make a long u shape handle and also you can use it to attach your tie back rope.

Last suggestion get a long section of exhaust pipe and make a extended length suction nozzle 3-4 foot will keep you up straight and face out of the water.

[jasong]

I run a very similar setup on my 3" and 5" except with mat instead of moss. Keep us updated how it works in the water, I'm curious if with a 2" there will be enough flow to run that big expanded without clogging up? My 3" with 5HP engine just barely had enough flow and clogged if the gravel got too angular, so I switched to lower profile and this year I'm running punchplate over it the entire length of the sluice (no pesky nugget gold in CO and WY to fret about).

[tvanwho]

Jasong,

I switched to the heavy expanded after it was recommended by WalnLiz on the Australia gold forum for sluicing for gold, as a primary gold catcher for fines/flakes. I can always switch back to a normal riffle setup if I have issues.All the hardware is lying around in various junk boxes or my storage locker. Am trying to get rid of several containers of old/spare parts this year and tone down the inventing.

  Are you in Arizona or ? I need a mining buddy in Arizona to go detecting with, sluicing even better. My old Az mining buddy has cancer and can't hardly walk 50 feet,much less do any digging. And do you have any suggestions for getting used to altitude in Arizona ? Had a hard time catching my breath at Rich Hill and Prescott, AZ a few years back. Then I saw a sign that said elevation 5,000 feet. I've lived in Chicago area almost 40 years now at sea level. Unfortunately, a lot of western mining areas are up in the clouds it would seem?

 Thanks for the advice guys.

[jasong]

I'm a bad person to ask about elevation because I lived my whole life above 5000ft and I spend time prospecting above 10,000ft  in CO/WY. so AZ is easy breathing for me! At 10k I dredge about 75% the pace I do at 7k.

That expanded might work better for you than me, I run UR or ribbed mat under mine so there is a lot of space between the top of the expanded and the mat, the miners moss on yours will fill the voids up and make the expanded have less relief than it does in my box. I'm curious to see how yours performs for that reason among others.

[Bob(AK)]

Tom, I am thinking along the same line as Jasong. That expanded is great stuff but I would find a smaller size for that small dredge, B

[tvanwho]

Ok guys,

I will dig up my old aluminum riffle tray and 1/8 inch expanded raised aluminum to use as a backup system.Its still damn cold here tonite, can't do any water testing till who knows, early April perhaps,unless global warming gives us an early spring...still have to find my quick connect coupler for the header intake too. I dunno why the photo can't be clicked on to show the whole dredge? Seemed to work when I did a preview...I also tried a 2 foot long section of pvc pipe attached to the suctiion nozzle last time but gravels would not suck up.It did work ok with 12 inch pipe extension. Long arming is not a lot of fun when your face is right up to the water, sure makes me nervous..never have tried a face mask and snorkel, any recommendations for a person with extreme near- sightedness?

 Hmm, I clicked the photo this time and it did open up to a full view....

[jasong]

If your suction nozzle extension made the suction nozzle itself sit above the water then you'll lose suction. Same reason jets get better suction when they are sitting under the water versus on top of it and why some people find that highbanker combos that use jets (like the Prolines) don't prime or work at all because they have them set up too high. To maximize power out of engines/pumps, especially ones operating near their limits, move everything as close as possible to the surface of the water if not into the water itself.

Just a hint that may come in handy some time from a guy who spent a lot of time trying to squeeze a lot out of a little. 

One spot I used to dredge the gold was all in the first foot of gravel, dunno why. So I longarmed all the time, and the water was normally opaque, couldn't see more than an inch or two into it. If you have a chance to use a facemask and a snorkel it's 100x better and easier being able to see what you are doing, do glasses not work with facemasks?

[sjmpainter]

Tom, give the expanded metal a try. I think it will work good. If not put in the riffles. I am running GoldHog matting in my 2 inch but almost went with the large expanded metal. So I am really curious how it works.

I am surprised the long nozzle did not work with the P90 set up. Make sure you have a good seal at the connections as gaps in the line rob a lot of suction at the tip. The other option is a mask unless you have air.

Another idea would be to slip a larger pvc pipe over the last several feet of hose and tip kind of like a splint.

Anyway I like what you are doing with the build it looks professional instead of cobbled together.

[sjmpainter]

FYI - They do make prescription masks.