| Lost Password :: Posting Pictures :: Who's Online :: Stats :: Memberlist :: Top Posters :: Search |
 |
| Welcome, Register :: Log In | Welcome to our newest member, jlivings2. |
|
1 people online in the last 1 minutes - 0 members, 0 anon and 1 guests. (Most ever was 55 at 21:51:42 Sun Nov 11 2012) |
| Pages: [ 1 2 3 ] |
| [ Notify ] | [ Print ] | [ Send To Friend ] | [ Watch ] | [ < ] [ > ] |
|
InspectorTom Offline 424 posts  Reply |
Thanks Dave,
You just answered one of my questions in your last post which was; is the entire sluice box adjustable or the screen sections. I run an old 5" Precision without the capability to adjust the sluice. It seems to have been made to "balance" when you crank it up & run water through it.  That's a big heavy classifier on the end too! I will be anxiously awaiting your article... Tom |
|
Dave_Mack Offline 324 posts Administrator  Reply |
Nice looking dredge, Tom! I used an 8-incher just like it for many years, and then a 6-inch version in our group projects -- which is what I refit with a double-screen system and sent to Cambodia.
It is true that Precision worked out the space between the screen and riffles. I was always pretty happy with the way my Precision recovery systems worked as a conventional dredge. I don't think you need to have an adjustable screen when you are talking about just one screen over deeper riffles (like the Precision set-up). But when we start talking about taking things to the next level, and effectively recovering (very) fine gold, I personally believe we have to reduce the flow of water over a shorter set of riffles. To keep a shorter set of riffles from being boiled out by the high-velocity flow necessary to wash larger material (4.5-inch in your case) through the box, you have to classify out the smaller material and direct it to a milder flow (which requires shorter riffles or they pack up). Since we have discovered from endless testing that 1/8-mesh material is processed very effectively by the Le Trap recovery system, the challenge has been how to direct all or most of the minus-1/8 material from a dredge into a Le Trap-type system without too much water-flow. That's where the double-screen concept came from. |
|
beammaker Offline 185 posts Reply |
Dave Mack and retrofit team
Thank you for the advice and the information. I will attempt to call for costs and Mr. Dunn's timeframe. Will probably order the materials shortly, just so I have them before he leaves. Down on a dead computer fan for the last few days. This conversation gets more interesting every day. Thanks Again----------Beammaker |
|
carver2 Offline 72 posts Reply |
Dave, I have a 6" dredge and have added a sump the last 20" of the box with a 1/8" screen over the top. The box is 24" wide, my question is, is there time for the material 1/8" minus to drop into the sump or do I need more screening before it gets to the sump area. I sometimes worry that the velocity of water will keep the very small gold suspended and zip right over the screen area. I wonder if I am over thinking this as gold and heavies drop first. Have added a photo of dredge. Any thoughts or ideas are welcome. Thanks, Will
http://gemcarver.com/will_picture/dredge_photos/IMG_0302.JPG |
|
InspectorTom Offline 424 posts Reply |
Thanks for the feedback Dave,
I remember the 6" Precision on K-15 on a group project in '07. When on K-15 in '09 with my dredge & my partners' 5" I dove down to the "wall" we had going out to fast water & took some samples in 5 gal. buckets. After panning out the samples it was disturbing to see how much fine/flour gold my dredge was discharging! I want to retain that gold! |
|
johnnye4 Offline 220 posts Reply |
I noticed that Keene Engineering has a product called “Miracle Mating”, it’s in their new online PDF catalogue….something to look at also. It appears to do the same thing that Mike Dunn’s product does.
Johnnye4 |
|
johnnye4 Offline 220 posts Reply |
Ok (Miracle Matting).....doesn’t do the same thing, exactly………on the prospectors channel under communicate and then under “mining equipment for sale or trade” (forum)and then under Keene super high banker, Keene engineering had a video and about three quarters of the way through the video the miracle matting was sized up next to a copper penny, the highest point on the matting is about 5/16" high.
Anybody knows the height or depth of this plastic sluice insert of Mike Dunn’s mold. Didn’t see the width of this Keene Miracle Matting but did see it’s sold for $1.80 a foot Yep…different products, but same category of concentrator?!?! Johnnye4 |
|
colo_nuggets Offline 529 posts Reply |
Both types will require different flows of water. Keene's mat is sold by the running inch around 250.00 for a 35 inch by 35 inch and needs about 137.5 gph per inch. Mike Dunns riffles same price 250.00 but thats for a six inch, per section about the same size. Prices could vary on the size of dredge, you would have to talk to him. I would not go changing anything on Daves design. If you have time for experiments before the dredge season is one thing. Making changes and taking it cross country for a season of production dredging to see if it will work is a whole different animal.
|
|
JABsWorld Offline 64 posts Reply |
Hi Dave! Another riffle and classification question! Given a dredge triple sluice box. If I place a 3/8" screen in the center box to classify the material for the side boxes and then placed a 1/8 classification screen with the letrap like riffles underneath for nearly the entire length of the side boxes, what is your opinion as to how effective this approach would be for fine gold recovery? JAB
 |
|
johnnye4 Offline 220 posts Reply |
I couldn’t agree with you more “colo nuggets”, that seems like common sense. So, Mike Dunn’s riffles are same width meaning 35” by 6” for $250.00, does anybody know the length of the riffles on the 5” Dave has?
If the riffles are 48”long, then that’s way too much money to spend, 24 inches is a $1000.00 and 48 inches is $2000.00. Keene matting http://1.bp.blogspot.com/_ZYnj8BHXQsM/StznY9QP5SI/AAAAAAAAAJ8/yFjxYAJtCus/s1600-h/2.5ultramat.jpg Someone tell me my math is wrong please. Johnnye4 |
|
colo_nuggets Offline 529 posts Reply |
To set up a 8ft box with 2 set of panels from Mike will cost you around 500.00. 26 inches wide on my box, I think they are about 3ft long. That will leave you a section for a nugget trap or another panel section. But there is a lot of other things that need to be built in, such as the screen adjustments and such. Im working on a couple of difference box setups for different dredges. One is a Precision Box setup, the other is Daves Cambodia box as I am looking into dredging over there part time. Maybe if your box was 16ft long it could cost that. But at those prices you could get the whole box done if it was 8ft long. My panels are supposed to be done Monday or Tuesday and then shipped out, once I get them I will post some pictures on this thread for you all to see. They are both a work in progress. Scott
|
|
johnnye4 Offline 220 posts Reply |
ya...Im looking at on my triple sluice outfitting the two outer sluices with this matting and leaving the middle sluice normal. All the or a high 90% of the gold I would get made it to the outer sluices, this is what I am adjusting at this time...nope haven’t been lucky enough yet to get bigger nuggets that would make it to the middle sluice.
I am considering running expanded metal all the way down the middle sluice in an attempt to stop the large rocks from building up when I am dredging alone....the triple sluice I can’t adjust separately, all are angled the same. Expanded (middle sluice) metal should help rocks just roll off…I hope. johnnye4 |
|
beammaker Offline 185 posts Reply |
Johnnye4
Can you still plan for 33-50% of your center box set up for an undercurrent? I also trust that my side boxes will catch much of the fines; however, the main center box (with an undercurrent microsluice) is where you could recover a tremendous amount of the fines lost over the season. A center undercurrent would allow you to possibly up the flow through the center box and still be very productive. Thus the increased water flow--with proper screening--should help to keep the larger rocks discharging completely. Then, as Dave said, you would still have room for scalper hungarian riffles at the end of the box to catch any larger sneaky nuggets. Beammaker |
|
a_reg Offline 121 posts Reply |
Hi Dave, You've done a great job on that dredge. It should serve you well on the Rogue. Nice flotation! A single guy like you might want to consider a few topside amenities. Berkeley Engineering offers just the right stuff. Boarding ladder is included. http://www.berkeley-engineering.com/CapeCodder.html My best, Harley |
|
johnnye4 Offline 220 posts Reply |
Beammaker
My center sluice measures 48” long by 16” wide and I loose about 14” at top where the side sluices get there flow and fines from , I need to extend all three of my sluices a good 24” to get more out of my fines. And then I may be able to have a 1 ounce day like Dave Mac did in three hours with that kind of change to my dredge…..diffinently excited for the details from Dave Mac about how to and material for this to happen. Flow is important so care will be given so as not to loose possible fines in center box. I was thinking of 1/2” minus expanded metal for the center sluice the entire length for a temp fix until the boxes can be lengthened and matting can be installed similar to Dave Macs 5” Cambodia dredge, and maybe on the two side sluices at top use the Keene matting for the first 20”. Johnnye4 |
|
Jim_Alaska Offline 2088 posts Administrator  Reply |
Great link Harley, thanks for posting it.
Jim
|
|
colo_nuggets Offline 529 posts Reply |
Dave on the Cambodia style box I noticed you have tried both. A nugget trap at the flare opening on the
8"- for the Klamath, and on the current 5" inch Pro-Mack model at the discharge. Going for the fine gold first on the 5"? Or is that just the way it worked out. Scott |
|
beammaker Offline 185 posts Reply |
DAVE MACK AND JOHNNYE4
Johnney4 I think on my triple I will consider adding the extra main and side box lengths at the head of the system. I do not know the exact depth of the box to get the undercurrent LeTrap idea correctly installed. 24 to 36 inches sounds like a good length though. Then leave the the ends open for scalping riffles for nuggies and nuggets. DAVE MACK: Can you help us out---I believe adding the new box length at the head of the boxes would work with your designs. Just what depth of box??? The nugget trap at the head is--of course--the best first step to getting the high dollar pickers. Thanks--------------BEAMMAKER |
|
colo_nuggets Offline 529 posts Reply |
If the nugget trap is at the head of the box all the very fine gold is thrown back up into the current. Unless you have a long box, 8ft plus I doubt it will settle back out. Big gold is easy. Im thinking that that flow out of the flare needs to drop as low as possible so everything can be adjusted on the screens,as far as water flow goes. Then the fine gold would be caught first. We will find out soon enough.
|
|
beammaker Offline 185 posts Reply |
Coloradonuggets
Point about the trap location well taken. The end works well for Dave and your insite is well understood. THANK YOU. DAVE: Still want to know the overall height needed for the undercurrent spacing. Beammaker |
|
Dave_Mack Offline 324 posts Administrator Reply |
This was quite a lot of work, but here is a much more thorough explanation of the system!
|
|
beammaker Offline 185 posts Reply |
Dave Mack
Thank you very much for this added effort on your part. The presentation and the explanations and picture/diagrams are perfect. You have answered my questions fully for now, and I am confident others will agree. GREAT JOB!!!! Beammaker |
|
Rod_Seiad Offline 632 posts Reply |
"Big gold is easy." COLO Nuggets
Now there is a great attitude, thanks Scott. Dave Mack- You did it again. Just about at the dawn's early light, when hope is nearly lost, out comes a rousing and uplifting article from you on NOT POLITICS but dredging. What a pleasure! Thanks. |
|
johnnye4 Offline 220 posts Reply |
Dave _Mack
On your five inch do you tend to get more fine gold in the last set of letrap style riffles or is it consistent fine gold threw the letrap style setup…this is once you have it all dialed in to production mode? And when you are faced with islands of black sand to suck-up do you change your technique with how much you allow in the nozzle? If yes how?? Wife and I were just on the Rogue River access point #10 on your Rogue map Feb. 11, 2011 and what I saw was islands of fine black sand sticking out of the river everything is covered in a thick black sand coating so…..I am very appreciative of your remarkable designs on dredge gold recovery…have purchased years ago your DVDs/books, and read twice over…what you have on gold recovery, also have been a 49er for years up till recently because of employment or lack of it my membership I am sure is gone, but did do some dredging on the Klamath with some success…But have never been faces with so much black sand…probably from the dam removal that normal dredge technique will not work…its like beach dredging with this much black sand….how would or will you attack this issue? Thanks in advance. Johnnye4 |
|
johnnye4 Offline 220 posts Reply |
Here is a few of the ladders I was able to find on the internet for water use, my favorite is the dog ladders.
The ability to retract the ladder when not in us is ideal….. http://www.overtons.com/assets/images/products/large/35607_L2.jpg http://www.overtons.com/assets/images/products/large/74632_L6.jpg http://www.overtons.com/assets/images/products/large/38805_L2.jpg http://cozywinters.com/popup/Dog-Boat-Ladder2.html http://www.overtons.com/assets/images/products/large/26014_L2.jpg http://www.overtons.com/assets/images/products/large/26014_L1.jpg http://www.overtons.com/modperl/product/details.cgi?r=view&i=26014&cID=SHOPPING johnnye4 |
|
johnnye4 Offline 220 posts Reply |
Found a few ways to make these new riffles:
Thermoforming manual is easy to follow and heat up the plastic with an oven or touch. Here is a web page with the abs sheets to purchase, they are all in mm but with a quick conversion table link it is easy to understand. http://industrial-enclosures.com/html/conversion_mm_inch_2x4b.htm The manual is 2.3mb and is in easy terms to understand. http://www.spartech.com/plastics/vfmanual.pdf Here is the UK link for abs plastic sheets. http://www.polycarbonate-sheet.co.uk/2.5mm_abs_black_smooth_sheet.htm johnnye4 |
|
Dave_Mack Offline 324 posts Administrator Reply |
Here is the full explanation with more images and some diagrams.
|
|
colo_nuggets Offline 529 posts Reply |
     Here's is a couple of pictures of the box Mike Dunn made, this thing is KILLER!! This box came in around 150 160lbs uncrated. 40 to 50lbs lighter than the Keene 3 stage at 210lbs! My measurments of the aluminum pontoons im making is going to be dead on. I am REAL HAPPY with this box. More pictures to come! |
|
RUSTY_HAPPY_CAM Offline 684 posts Reply |
Scott, Your sure gona need a bigger garage if you keep building bigger toys. People would think you live on a river where you could use that stuff.
|
|
colo_nuggets Offline 529 posts Reply |
 Rusty you should see my back yard! I plan on moving back to the country and getting some land again. I have found I like some elbow room between houses. Things are just starting to turn around in the housing market here, but it got rough the past couple of months. Getting some breathing room again. Scott |
| Pages: [ 1 2 3 ] |
| [ Notify ] | [ Print ] | [ Send To Friend ] | [ Watch ] | [ < ] [ > ] |
|
Total Members: 4307 | Register :: Log In :: Administrators The time is 13:29:43 Sat May 25 2013 |
![[Most Recent Quotes from www.kitco.com]](http://kitconet.com/charts/metals/gold/tny_au_en_usoz_2.gif)
|
|
![[Most Recent Quotes from www.kitco.com]](http://kitconet.com/charts/metals/silver/t24_ag_en_usoz_2.gif)