BY JUDE COLLEN KENDRICK

 

This is a picture that you will seldom see – me getting up at 5:30 a.m. full of excitement – to vacuum! Yet, I spent some of last summer and almost all of this past winter, doing just that. It wasn’t “dust bunnies” I was after, however; it was gold!

A few Decembers ago, I wrote a Christmas dry-washing article about the Mojave Desert. I said that I had made a portable vack machine to clean off the caliche (cement-like material) shelves that one encounters out in the desert. But it was not until last summer on the Klamath River near Happy Camp in California that I actually used the vack machine for what most people use them for, which is crevicing.

I knew about crevicing, of course, but it just wasn’t my thing. In fact, on several of my surface mining (motorized sluicing) trips there would be lots of prospectors around the creeks crevicing and getting gold. I cannot recall, though, at that time seeing anyone with a vack. They all had store-bought or homemade tools to get the gold out of all the nooks and crannies. On the Klamath, I borrowed a Mack-Vack made by Pro-Mack in Happy Camp, because I did not have the space to bring my motorized sluice along. My little portable vack that I had made was in the “equipment graveyard.” I had brought gad bars and digging tools, so I was set up to crevice. I will admit that I was not very enthusiastic about it at the time. I like to see dirt flying and lots of material running through my equipment. But it did not take long to change that lack of enthusiasm!

The bedrock around the area where I was on the Klamath broke apart fairly easily. I walked around trying to find the right kind of hard-packed gravel between the seams of these massive slabs. I had only used the vack for a while and had only about half of the 5-gallon bucket filled (not much material, I thought). Yet, when I panned it out, there was a beautiful match head-sized nugget. Now, this type of prospecting wasn’t bad at all!

Kay Tabbert and her husband Chuck, both members of The New 49’ers, were in the same area at the time. Chuck was busy dredging while Kay, with only her little hand tools, a whisk broom and dustpan, was crevicing on some bedrock not far downriver from me. All of a sudden I heard Kay calling for Chuck (and anyone else around). So I walked over to see what was going on. I could not believe it. Kay had separated a rock about the size of a melon, and in the crevice, stuck to one side, were 7 beautiful large flakes of gold! Just like that! I could not get back to my area fast enough!

I had dredged for years and I knew just how to spot the places where the water would deposit gold. It was really no different from working in the water – I just did not have to get my hair wet! I was feeling a little impatient, though, as I never did wait to fill up an entire 5-gallon bucket with material using the vack machine. But what I did pan produced great little “clinkers” of Klamath gold.

Unfortunately, I only had about seven days last summer up on the Klamath. But, I had five months this winter to play in the dirt. Lucky for me, I got “hooked” on vacuuming crevices!

I was prospecting Quartzsite, Arizona and the surrounding areas. The desert had a lot of rain this past summer and everyone was hoping that the washes would “pay off!” I decided to sell my beloved “Nick’s Nugget” dry-washer, as I knew I was going to be out prospecting alone a lot. As great as it was, it was too heavy and clumsy for me to manage on my own. I purchased a small dry-washer combo (with the vack option) from my friends Bob and Linda Taylor. This was great. One engine ran both and I could carry everything in one trip.

Hunting for bedrock in the desert is certainly not like on the rivers. It definitely does not expose itself as much. Yet in many places it is not deeply hidden. I was finding many places in washes where people had dug down to bedrock and had not even touched it with a whisk broom. So, guess what I did? They had already done the heavy work. I just sat there and vacked up the gold!

Finding new places to vack was not easy, as I have said. I have known for years, from experience, that the gold in the deserts isn’t always where it is supposed to be. What would look like great bedrock on the rivers often means nothing in the desert, mostly due to the lack of water volume and movement in the deserts. When I arrived at Quartzsite I met up with Al Powell, who is also a New 49’er member that I met briefly while on the Klamath. Al and I were finding “perfect” looking bedrock, in established gold areas, that produced nothing. We were always shocked, because all the “recipes” for gold were there. We could have found more gold in downtown Quartzsite! We were not giving up, however!

I decided to take five days and go off to find a hot spot for Al and me to work. I found a very small ravine below a heavily mined area that had a large section of bedrock exposed. It took two days of pulling “Buick-sized” rocks to work myself down to where I was getting some nice gold. After the fourth day, I showed Al my gold and took him out to the spot so we could clean it out together. Well, I suppose I did my job too well; as except for some small flecks, Al and I vacked all day and got nothing large. “OOPS! Sorry, Al!”

The weather in the desert turned nasty, with off and on heavy rains that went on for days. Consequently, all of the dry-washers around the desert were silenced. The ground in places was damp as deep as eight inches down, which forced people to grab their gold detectors and head out nugget-shooting until things dried out. Yet, Al and I were not held back; we were still out there, in a new area, with our vacks. We didn’t have any trouble bringing up the damp gravel, although the two of us looked like “mud pies” at the end of the day.

I had, from the beginning, been running my vack materials through my dry-washer so I would not have to pan as much concentrate. Even the damp material did not present much of a problem, as Al and I just ran everything through the dry-washer two or three times. I am sure that the people driving by during those wet days who saw the dry-washer running, said to themselves, “They are crazy!” Well, that is a whole other story, but we did have our pretty desert gold to look at all the way back to our desert “sanitarium!”

I would recommend purchasing a vack to anyone, even as a backup to your usual motorized sluice or dry-washer. And, now, when “housework” day comes each week, I won’t dread using the vacuum; I will just be practicing! Good Luck!

 

 
Dave Mack

“Gold recovery systems also trap the other heavy elements — like iron sand. Here follows some helpful information about how to accomplish the final separation.”

 

By Dave McCracken

Using the Le Trap Sluice to make your
final clean-up go faster.

Dave Mack

Because we have so many innovative, active gold dredgers and small-scale miners on the Klamath River, I don’t recall exactly who came up with the original idea of using a Le’ Trap sluice for final cleanup. When I first heard of it, I had reservations. We have been improving the fine gold recovery on our dredges for years. I was afraid the plastic sluice in final cleanup would lose a large percentage of the extra-fine gold that we are now recovering in our dredges. However, upon close inspection, this proved not to be the case.

One of the most time consuming jobs on any serious gold dredging activity is the final cleanup procedure of separating your gold from all of the other heavy black sands and materials which are also recovered by the dredge. My personal operation is utilizing two eight-inch dredges. We are working in an extensive fine-gold paystreak, which requires us to cleanup about two-thirds of our recovery systems at the end of each day. This amounts to about three five-gallon buckets of concentrates to process. In the past, we have utilized spiral wheels and just about every other kind of cleanup device available to process our final concentrates down to our final gold product. Always, with any of these devises, we succeeded in reducing the amount of concentrates down to about a handful, which we would then process with mercury amalgamation.

During the last several years, we have been using a professional shaker table to work our concentrates down. We found that the shaker table was faster than spiral wheels and the other devises we had tried. Even so, with three five-gallon buckets to process, we were spending several hours each day just running our concentrates across the table. Once the concentrates are worked down to a handful-sized amount, the final amalgamation process only takes about a half hour. In other words, the most time consuming job had been to work the concentrates down to just a small amount.

Shortly after we heard that the Le’ Trap sluice was being successfully used, there were other dredgers on the Klamath, dredgers who knew what they were talking about, starting to rave about how fast and effective the sluice was for final cleanup. Lots of people were starting to use the new system. Consequently, we decided to give it a try. We were quite impressed with the results!

Basically, the system is quite easy, and also quite inexpensive. The Le’ Trap sluice retails at about $90. When used in conjunction with a dredge, no further equipment or pumps, etc., are needed, except a garden trowel of some kind to shovel concentrates with.

We start our dredge and run it just over idle speed to get a small amount of water moving through the primary dredge sluicebox. Water flow through the Le’ Trap sluice can be adjusted by engine speed, or by placing any flat objects under the tail end of the sluice. If you do not have enough water flow, you will notice the black sand does not move through the sluice with any regularity. Rather, it tends to pack up and bury the riffles. In this case, you will notice your gold sitting on top of the black sand, rather than inside the riffles.

If you have too much water flow, you will notice that the black sand flies through the box, with little chance to make contact with the riffles. There is plenty of margin for error. Ideally, with the proper water flow, as you feed concentrates into the sluice with a garden trowel, you will watch the black sands work their way down the box in an orderly procession. The flat, smooth section of the box ahead of the riffles allows the pieces of gold to trail along just behind the black sands. And the riffles stay somewhat clean and open. You can watch the flakes of gold wash down and drop into them.

When done properly, you will find 90% of your gold trapped behind the first four or five riffles. A few pieces, just a few, will work their way further down. But, almost none make it all the way out of the Le’ Trap sluice. We were working with several ounces of very fine gold per day; and to test the system, several times we brought all of the tailings home to see what we had lost from the Le’ Trap Sluice. It was never more than a half of one percent of our total gold recovery.

And, really, we didn’t even lose that gold, because it simply ran back into our dredge recovery system.

The Le’ Trap sluice is a one-piece molded unit which has a unique set of very efficient short riffles which seem to suck the gold right out of the water’s current. Cleanup of the sluice is simply a matter of tilting it up and dumping it into a tub or gold pan. The final product ends up not being much more than a handful of gold and your heaviest concentrates. Needless to say, this is much easier to deal with, rather than having to lug several heavy buckets of concentrates up the hill to our vehicles!

The main ingredient that we saved with this new cleanup system is time. We were able to feed the Le’ Trap sluice about twice as fast as our commercial shaker table. And, we only needed to screen the concentrates down through a quarter-inch screen using the Le’ Trap sluice, rather than through a quarter-inch mesh screen, then an eighth-inch screen, and then a 20 mesh screen to use the shaker table. This saved a lot of time in itself.

Plus, the system was so simple to use, we purchased a second sluice and used one on each dredge to cut our cleanup time in half again!

Since it only takes one person to feed the Le’ Trap sluice, we would put everyone else to work with end-of-the-day organizational activities while the concentrates were being run. Things like putting airlines and weight belts away, transferring used gas cans off the dredges, minor equipment repairs, etc. About the time that everything is put away and finished for the day, the concentrates are also finished, and we only have a half-hour of finish-up when we get home. This is a HUGE improvement over our old systems for final cleanup.

While smaller dredges have lesser amounts of concentrates to deal with at the end of the day, the time it takes to work them down usually is considerable, even on a three-inch dredge operation. That is, providing you are recovering worthwhile amounts of gold, especially fine gold. I don’t see any reason why the Le’ Trap sluice could not benefit any dredging operation where the dredge sluice is wide enough to allow the Le’ Trap box to fit inside.

We will be using this system in our operations during this upcoming season, and in future seasons until someone comes up with something better and faster. Anyone want to buy a good commercial shaker table?

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