8 inch gravity sluicing

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spaghettigold

spaghettigold

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Foto0056.jpg got the clamps,cutted the slots to compress the hoses and secured all the clamps with jacketed tightrope

Foto0057.jpg

Foto0055.jpg



Foto0061.jpg test with a piece of 110mm hose.

Can get the flare off my to do list.But the list is still long to read...
 

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russau

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May 29, 2005
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nice looking job on this equipment ! BUT on your twin jet setup I thought a person needed more distance on the location of your jets to aquire more suction (4 x diameter of your hose for max. linerer flow) .........with your jet orfices right at the flaired section ,it would seem to me that your suction would be impaired....OR am I over thinking this?
 

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spaghettigold

spaghettigold

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Hey russ

The 2 inlets are no high pressure lines or jets so to speak.
They are not there to increase suction on the 8 inch line but they are there to increase waterflow in the box and increase yardage .
Since i,m working in a low drop spot again this summer the waterflow would be weak again,barely clearing the rocks,and undersection clogging with lights . Thats why i replace the punch plate over the undersection with wire mesh for more waterflow in the undersection.Also raising the mesh up to 3 cm(1.18 inch) over the expanded for more flow,made a new frame over the expanded without the hungarians i had there to push it down -for more flow.
With all this flow just for precaution and to be able to run a little longer without cleanup ,the additional flared section at the end.

For the yardage,theoretically now with the new flare inlets, up to 3 dredgers could work with the same box,but most likely it will be 2(if i get it all done cause i,m not finished yet and as usual the first test will be in my short season ) cause one of us 3 has to be the sluice tender.

Enyway thanks for the suggestions russ,if i ever build a jet i will ask many questions
 

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spaghettigold

spaghettigold

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vid with the improoved waterflow at the same location like last year,so same drop(c.a 3-4feet)
Flow was good now for the old part of the box but the new added wider part needed a additional hose for proper clearing

 

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spaghettigold

spaghettigold

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vid of the dredge with only one 110mm(4.3 inch) hose running.When the dredge was running properly and we had no issues with tailings(which is one of he main problems)we dredged together.He worked the upper layers a bit as preparation.Later i dredged down to the clay.You can see how only left part of the dredge is getting muddy.
 

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spaghettigold

spaghettigold

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Foto0341.jpg Foto0342.jpg Foto0343.jpg

The whole friggn oversize rock wall we threw there during 2 weeks.Left of the dredge in the first pic are some of last years.Later we had to remove also smaller rocks by hand to avoid to much tailings build up in front of the sluice.Also we had to build several little dams upstream,as water diversions ,to bring the water to our pool.Waterlevel was sinking everyday and so in the first week we had to spend everyday c.a 3 hours to maintain and expand our diversion dams to compensate the waterloss.Then we had weatherforecast with 2 days thunderstorm warning,which cost us another 2 and a half days ,partly for securing the equipment and during the bad weather we stayed out of the riverbed to avoid possible flashfloods.The flashflood came but it was a little one:BangHead:
 

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spaghettigold

spaghettigold

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at this point thanks to the forum and especially one person that gave a good advice in a thread few months ago.Can,t remember the thread title or the person(was it goldwasher?) but it was about gold behind boulders and the member said something like:take the wideness of the boulder and multiplicate with 3or 4.(can,t remember) Then check the resulting distance behind the boulder .
Last years boulder is about 10 feet wide,but we dredged mostly around the boulder.When i read that formula i wanted to check.

My first rough gold View attachment 1340226 Two days sampling,moved about 3 yards View attachment 1340227 View attachment 1340228 View attachment 1340229

I didn,t wanted to post them in may because i had only2 days prospecting time and the deposit had to last there till july to be mined.With todays computer tools you never know.Locals could read this too
. But hey ,i gave you overseas all a good chance to mine it away in front of my nose cause last year i told,ya all that i only mined it close around the boulder.:occasion14:

Mods,why are the pics not showing ?When your logged in you can click on them and they will show up,not logged in it says "invalid attachment "
 

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spaghettigold

spaghettigold

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A walk thru the new set up

Foto0292.jpg - ribbed rubber Foto0293.jpg - Miners - Moss-i know some of the dredgers don,t like moss because it packs solid when the dredgers turn idle for a break or something.However my gravity dredge never runs idle cause it,s work to turn the water on and off,water keeps going full till clean up time and in this case i trust a miners moss much more to prevent from scouring rather then a flatter mat with less hide out space and friction.

Foto0294.jpg -expanded section Foto0295.jpg - wider section with adjustable angle,mounted piano hinge as you can see in post nr.188.The wider section already increased my recovery as i will show later.
Expanded metal a la bill in costa rica and 4pounds grating .For the next building season i want to weld the mesh support iron directly to the mesh ,instead to the expanded so in case i want to run without classifier the mesh supports don,t stop the rocks.
 

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spaghettigold

spaghettigold

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Foto0296.jpg - My ramp classifier seems to have inspired the commercial manufacturers,if this is the case i,m feeling honored. Foto0305.jpg

Foto0302.jpg -Riffels at outlet and after the expanded,different angles and heights

Foto0303.jpg -View at the outlet riffels

Foto0304.jpg -classifiers in-ready
 

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spaghettigold

spaghettigold

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Foto0288.jpg The big flake there was found in the first part of the new wider section.That means it jumped over the first half inch screen riffels,then over the open riffel section,then it had no chance over the fifth of an inch screen and third of an inch screen that are covering the fines section.It only dropped thru the half inch screen when the sluice starts widen out.Part of the problem i guess is that my first riffels are set deeper then outlet height of the flare.That means they are like dropriffels.High velocity at the outlet,a big but very flat flake and a drop riffel is the recepy for for goldloss it seems.Fortunately the wider section catched it.
 

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