dredge construction

[oro e lavoro]

hi together

Real world slapped my face today.
Waterdam(n) sealed not enough ,when hose was barely half filled the pressure pushed the lid too much.As result the water entering the hose, could not compensate the waterloss of leaking lid.Could not prime the hose,no dredging.
Even though it did not work out in time for my dredging trip, thanks to all in this forum for the good advices and patience.

Saluti,Emilio                                                 (the oversize- couplings seem                                                                                                                                             to work fine,will fill the                                                                                                                              screwholes  with silicone)                                                                                                          

                                                                                                         s                                                                                                       

[lbd]

Hi Emilio

What is the waterdam(n)...?
Tto seal the spiral where you want to put the silicon, you can remove the couplings from the hose....wrap a piece of rope (the same size as the grove in the hose) around the spiral with a little silicon, then refit the coupling... I do a similar thing to help the hose clamps.

lbd

[oro e lavoro]

Hello lbd,

Sorry,i mean the watergate(my english). Here you can see the lid that did not seal enough. That caused the main problem.
And you mean a banding sleeve i think.
I considered to do what you proposed with a pvc hose that fits in the spiral,that would be flexible,but the clamp and coupling was minor issue,(but also need to be better.)  also the conection to flare was not good,its too tight,i barely can push the hose inside flare,will try to grind the pvc spiral there a bit. Resumed altogether i have too many issues  for time and money i have left at the moment. I have to let go at the moment,its over a half year now i put effort and bucks in this project,now i have holydays and and want to spend the time in the water.I will re-attack when i come back from  my 4 inch trip.(

Thanks again lbd 

Saluti,Emilio

(P.s. only the screw holes of coupling would be filled with silicon,the coupling would still be removable)

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[lbd]

I am confused... what is the purpose or reason for the water gate blocking the outlet from the flare?

I just have a large heavy rubber sheet there.

[oro e lavoro]

hi lbd

I,m gravity sluicing,no way to use motors here.
to prime the hose ,especially the 8 inch hose i need a watergate to fill the hose completely with water before opening the watergate.

[lbd]

right... now I understand

Thanks

[oro e lavoro]

Yep,in this part of this creek for example,i could dredge up(theoretically,because i live in prcautionally principle and other criminal issues land) 200 m of streambed with my 16 m of 8 inch hose,(with rest of the creek still to be explored for drop available)with running coast of about  3 meals a day and the wear on the hose and  the sluice. (and ouf course the initial expends of sluice  building).
Gravel size also very good,not much blacksands but only very fine gold ,and not very high contents(2ooo specs for a gram and maybe 0.1gram per cubic yard in the better spots i could find till now,),i just test the capture rates of new sluices  always here. _ Conglomerate ,sandstones, conglomerates .

As i mentioned in other post i can not make a living out of it here where i live,but i would certainly consider gravity sluicing if i had a regular claim with drop available or the possibility to build little dams,immagine the cubic yards workable,with a 10  inch (if theres enough water)without gasoline coasts to recover other then  the fuel for a dive compressor if you need to go deeper. 

Saluti

Emilio

[oro e lavoro]

Finally a wire mesh section done. 

Saluti.Emilio

[oro e lavoro]

Hello everybody

The new lid-system for hose-priming.
I initially wanted to avoid it because with this system ,after hosefilling,i will have to remove the layflat and attach the hose to flare while water is running,but seems to be a prooven design and as always theres no time for invent/testing new things.(piece of hose only for demonstration purpose)


                                                                              
Saluti;Emilio

[oro e lavoro]

Hello again. screwholes of couplings filled with silicone.


One thing i noticed.
Why does keene use punch plate for 2 stage classification on the over under sluices?

And also which devices you can recommend for further concentrating the dredge cons before panning,keep in mind i can ,t use motors or mechanical things,le trap?

Thanks;  Emilio

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[RKC]

G'day oro e lavoro,


There is most likely a simple production reason alone why Keene would chose to use punched plate over the better alternative, woven wire mesh. When dredges are mass produced on a production line all sorts of considerations come into play that are apart from just choosing what is the best design to make the best operating dredge. For example, maybe, Keene already have a lot of money invested in a plant to produce punched plate that they want to get as much use out of as they can before the plant reaches the end of its life cycle. Or, maybe, Keene can get bulk quantities of punched plate much cheaper than they could purchase woven wire mesh. Who knows! (or they might even think punched plate works just as well, or better, than woven wire mesh). This is where the smaller dredge manufactures can be much more flexible than a large company like Keene. If a small company can see the advantage of using woven wire mesh over punched plate, then there is not a possible financial liability in changing. And the change can be done quickly. Also large companies like Keene are much less inclined to change a design if the product is selling. Any design changes Keene have made in the last 20 years have been changes that had already been made to the dredges from smaller companies and were changes proven to work by the smaller companies.


There are numerous methods available to separate the gold from dredge concentrates. And its easy to be confused by all the weird and “wonderful” equipment discussed on recreational Internet forums for separating gold from concentrates. But, what anyone who wants to mine viably has to keep in mind is that most of what is discussed is untested theory written about by theoretical “miners” whose hobby is ‘discussing’ equipment.


What I would point out as the most important consideration, is not to go overboard with extra unnecessary equipment to treat the dredge concentrates (unless there are special circumstances such as a lot of heavy black sands). Treating the concentrates should not become excessively time consuming so precious time is used up that would be better spent underwater getting the volume through the dredge. With treating any concentrates its always essential to classify before anything else is done.


The simplest means of reducing down dredge concentrates is to use the dredge itself. Have the classified concentrates (the fines) in a container on the dredge and then run the dredge motor/s at low revs so water is only gently flowing through the sluice box. Add the classified concentrates slowly by hand at the head of the sluice until most of the black sand exits the sluice box. You will visually be able to easily see (by running clear water through the sluice box) when you are overloading the sluice and when you need to stop adding concentrates. I used to do this on a triple sluice dredge I once had by just using one of the side box's to concentrate down the fines.


The above considerations are meant to apply to production dredging where the dredger has to consider such important aspects as the time it takes to do something so viability can be maintained. When it comes to recreation dredging there is a whole different motivation involved. You will often see recreational dredgers with all sorts of fancy equipment for treating concentrates. Recreational dredges often seem to get more fun out of treating concentrates, rather than actually dredging, and this is why you will often see them with all sorts of fancy concentrating equipment (that takes up more time than justifies the few extra flakes they might get by using the equipment).


Its rarely worthwhile in most production dredging project to do any more than use classifying and sluice boxes (and gold pans) to separate out the gold. An exception would be if dredging somewhere like the lower Clutha river in Otago, NZ, where the great bulk of the gold is very fine which is locked in massive amounts of heavy black sands.


Regards,
Rob (RKC)

[oro e lavoro]

Hi Rob

Yes the punchplate,i noticed the inefficiency (lack of open area)because always the first 2 rows or so of the expanded metal section where emptyand then with every row theres more material.Things i liked  on the punch plate where rocks slided well over it and the water entered slowly(lack of open area) in the fines section.So thought keene uses punch plate over fines section because it sloweres waterspeed inside that area(taking the loss of the material that didn,t make it thru the punch plate)
So to have the good efficient classification  i need the wire mesh open area. The correct question i should have asked is:When using wire mesh for the fines section ,is it mandatory to do double classification like mr Mc Cracken style ,to also slow the water in the fines section?Now i have only single classification 8mm wire mesh over the fines section,hope it don,t flushes out the expanded over ribbed mat.(sorry,zero experience with it)

Now for the clean -up sluice.

Normally i never did full clean up in during my dredging stay in Italy,just cleaned up the sluice every evening,put the concentrate of the day in a bucket,wrote a nr .on the lid that corresponds to the place where it was dredged and then panned out everything at home.
Took me 1and a half hours calculated altogether on the 4 inch per dredgeday.
Now it will be (if all works...)the 8 inch and i will team -up with the local goldseeker i got to know during last trip.Think i will have at least 6times the concentrate of the 4 inch('?) and we have to split the gold(flake )Was looking for something to shorten the clean out time. Plan is to do full clean up and splitting every evening,so theres no potential for suspect or similar things.Think i,l go with the sluice in the dredgesluice style,because my sluice has no sidebox for fines,l and will try to imitate the low revs of a motor with a lid that partially covers the suction tip intake.But theres no hurry because i wan,t get it done for this trip (no time)Guess it will be a lot of panning..

Thanks rob

Emilio

[oro e lavoro]

Hi everybody

www.youtube.com/watch?v=RDjDQHFbDjk&feature=youtu.be
 
More later,saluti:emilio

[oro e lavoro]

HI ,i almost forgot,found these mats in shell petrol filling shop.Try them out for a clean up sluice as in the old forum posts (hazelwerdt mats)there where recomended but hard to find.  saluti,emilio

[RKC]

G'day oro e lavoro,

That mat looks perfect. You were lucky to find it.

Regards,
Rob (RKC)