Dredging with a New Type of Dredge
By Steve Lintner
I have been happily dredging with my old 4" dredge for the last 15 years, but when I dredged on the South Fork of the Yuba River I found out, as you get older, its harder and more difficult to drag a dredge up and down the steep rocky drop to the river. I thought to myself, "There has to be a better way to do this without this extreme hardship."
As I was reading a copy of the California Mining Journal, I spotted an ad for a dredge called a Gould-Bazooka. It looked too simple to replace my dredge, but my curiosity was peaked; I had to find out more. The article listed an Internet site, so I looked it up. When I first saw the pictures of the dredge in the water, I had my doubts as to whether it would really work. I then read the write up and the question and answer section and thought, "There must be something to this gadget." I decided to call up the manufacturer (Reggie Gould of Gould Engineering) and talk to him one on one.
I fired every question I could think of at Mr. Gould and he answered most of them. When I stumped him he would merely say, "I just don't know, but I will look in to it and get back to you." I have been dredging for enough years that I figured I could come up with some questions to stump him. We must have talked for over an hour, and then I decided to give my phone bill a rest.
For the next two weeks I kept thinking about the new type of dredge, but was still not sure about it. Then a funny thing happened. I was at a Miners Club Meeting when I heard a guy talking about the Gould-Bazooka. The speaker looked like the same guy I had seen dredging in the Journal picture. Thinking it couldnt really be him; I walked up and asked if he was associated with the product he was talking about. When he said yes, I explained to him that I was the guy who had talked with him for over an hour on the phone recently about his product. He said he had one in the truck, which he had brought to do a "Show and Tell" to the club.
After his presentation, I asked if I could see it work in person. He replied, " Yes," and said we could run it at the next dredging outing. I said that would conflict with my Tuesday and Wednesdays off, and suggested we go to my claim.
We set up a date and I took him to my claim for a day of dredging. The pump and motor are the heaviest items to drag down the hill, so I strap them to my backpack and walk them down. On the second trip, I took Goulds newly designed dredge and hoses and headed down the hill. He didnt appear to be in that good physical shape, so I carried most of the equipment. The device he brought with him was a 2.5" dredge. It was simple to hook up; all it needed was a 1.5" pressure hose between it and the pump. The suction was very strong and I kept plunging the nozzle into the sand and plugging it up. He jumped into the water and held the nozzle skyward and said, "This is how to unplug it". He was right, a big gob of sand shot out the back portion of the dredge. Gould said, "We have to recharge it now because it is full of air." He then plunged it in the water and said, "Now it is ready to go." Before he would let me dredge again he said, "This dredge has quite a bit more suction then you are used to, so you have to let the water mix with the material." I reminded him that I have been dredging for over 20 years and I knew a little bit about dredging. He handed me back the dredge and said, "Go for it." I have to admit it, he was right; you just have to put the nozzle about 2" from the bottom and it will suck the material to it. The biggest problem I encountered was flat rocks. When you put the dredge nozzle over them they fly off the bottom and stick to the end of the nozzle. It took me awhile to get the hang of it, but I was able to fool the flat rocks by dredging the corners of them where they would not lift off the bottom.
The one thing I really liked about the dredge was the way it sucked the gold out of the cracks in the bedrock. You could lay the nozzle across the crack and listen to the material work its way up through the nozzle and into the capture portion. I asked Gould when we should clean up and he said, "It depends on how much black sand you suck up." I decided after dredging for two hours it was time to have a peek. At that point I was curious as to how we were going to get the gold out of the dredge. He said, "Get me a 5-gllon bucket and I will show you how to clean out this baby." He had me turn off the pump and then he merely removed the front nozzle and poured the contents into the bucket. He filled the outer tube again with some more water and poured the remaining contents into the bucket again. He then re-installed the nozzle and said we could continue or we could pan the material in the bucket. I wanted to see if we had gotten any color before I wasted anymore time dredging.
To my amazement we only had two pans full of material, which appeared to be mostly black sand. Panning the black sand is a lot harder then panning the overburden material. The specific gravity of black sand is around 5, where gold is around 19. Even though the black sand is 1/4 the specific gravity of gold, it is still very difficult to pan out without losing the gold. I would usually take this material home and process it with my Blue Bowl, but I wanted to see the gold and figured it was worth losing a few small flakes. I thought it would take forever to get rid of the black sand, but I finally reached a place where the gold started to appear. It was beautiful, gleaming in the sunlight; the whole edge of the pan was covered with gold flakes. As I swished the water around and around in the pan I could see there was a lot of very fine gold mixed with larger flakes of gold. This was a new experience for me, I had never seen this much flour and fine gold. I decided at that point I had to own one of these "critters" for my own.
We dredged until it started to get dark. At that point I didnt pan every cleanup, I just poured the contents into the bucket, which was getting very heavy, so I decided to pan it out and reduce the weight. This was the moment I had been waiting for, when the gold starting appearing in the pan. It was beyond description; with every swirl of the pan I would expose more and more gold. When I started packing out the equipment it all seemed to have gained weight, it was definitely heavier than when I had first hauled it in, but I had brought back some color, so I didnt mind the extra weight.
I drove Gould back to his truck at our meeting spot and, the following week, purchased the 2.5" Gould-Bazooka at the next club meeting. I thought it would be neat to try out his new Tri-jet, so I purchase one of those also.
A year had passed when Gould said he was building a new 4" dredge design and that it wouldnt be available until it was thoroughly tested. I volunteered to help test it, because I was very curious as to why he was changing his design. Finally I just said it, "Why are you changing your design when it works so good?" He said the answer was complicated, but the short answer to the question was that he found the Suction Nozzle was 67% more efficient than the Straight Jet Venture he was using for the 2.5' dredge. The results of Goulds testing were published in the December 2003 issue of the California Mining Journal, after which he had decided to build a 4" dredge and his own 4" Suction Nozzle. I volunteered to weld it together for him, as he might have to make several models to see if the design was right. At first he was reluctant to let me help him, but we had been dredging together for a while, so he finally agreed. I welded the nozzle at a 45-degree angle and installed the Jet right above the weld and parallel to the output flow of water. I called him and asked what to do with the nozzle I had welded together? He said, "Just bring it along with you and I will meet you at the parking lot."
The next week we met at the agreed time and place and headed for the dredge site. I had my doubts as to whether my 5 HP (horsepower) Honda was going to be able to run this dredge with a 30-foot pressure hose. The pressure hose on my old dredge was only 5 feet long, so the 30-foot hose had to create a big pressure drop. When we finally got to the site, I hauled down all the equipment and set it up. The actual dredge he brought was quite a bit different then the 2.5" dredge I had bought from him. The outside tube was the same, but was missing the Straight Jet Venturi at the rear end. The front end of the dredge did not have a nozzle, instead it had a 5-foot length of 4" dredge hose. He asked me for the 4" Suction Nozzle and installed it on the other end of the suction hose. It appeared his design had changed from a suction dredge to a pusher type dredge. The front nozzle was sucking the matter through it, but was pushing it to the input of the dredge. I had brought the 2.5" I had previously bought from him for a backup in case the 4" did not work to expectation. I connected the pressure hose to the dredge and the other end to the pump and started the motor. Just as the motor picked up speed and the hose started to straighten out, a huge stream of water hit me square in the face. I almost fell on my rear end trying to get out of the way of the gushing water. After I stepped back I could see the problem. The hose fitting had slipped off the pump output. I was right about the 1.5" pressure hose being too small; it was building up too much pressure. He assured me that this would work and added another clamp to the hose. He was bent on making this dredge work, so I fired up the motor again. I watched the pressure hose straighten out as the air was being driven out, and then the water started to pour out the rear end of the dredge. I grabbed the handle on the top of the suction nozzle and started dredging. To my amazement the suction was really strong; I could hear the rocks banging in the nozzle and traveling through the dredge. In a short time I had dug a huge hole 4 feet deep and 5 foot in diameter. One thing was certain; this baby could dig, but would it also recover the gold?
I decided to dredge for only an hour and then do a clean up. I shut down the motor and asked Gould how to do a clean up on this new dredge. He laughed and said,"This is a piece of cake to clean up." He removed a 3" plug from the bottom of the dredge and set it over the top of a 5-gallon bucket. He had me start the engine and run it at an idle, and the contents of the dredge starting pouring into the bucket. When the water coming out of the dredge looked clear he asked me to shut down the motor. When I looked into the bucket it was half full of black sand. I could not believe my eyes; we had only been dredging for an hour. We both started panning out the contents in the bucket, but all I could see was black sand. I got to thinking that maybe this dredge was moving too much material and not getting the gold. As I was panning out the last of the black sand, I could see gold covering the bottom of the pan. I guess it does get the gold and move the material.
When we finished doing clean up, we looked at our impressive gold recovery. I decided I had to get one of these dredges; it way outperformed my old dredge and was light as a feather. It was hard to believe that this dredge was a fraction of the size of my old dredge and had recovered even more gold.
Gould said the unit was his proto-type and he didnt have any to sell. It took me awhile, but I finally convinced him to sell me the proto-type. I can honestly say that it is the best recovery dredge I have ever seen or used.
Note: If you would like more information on the dredge, log onto www.gouldeng.com.