Homemade Dredge?

goldmadness14 · Oct 21, 2008

I was considering building a homemade dredge. I see these Keene dredges for thousands of dollars. Isnt a dredge basically just a water pump?

warsawdaddy · Oct 23, 2008

BTW,I haven't seen a question on the size dredge being considered or where most of the dredging will take place.Are you considering a1,2,3,4,5,6,8,10"? I would think a lot research should be done before any construction begins.

kuger · Oct 23, 2008

Another thing I do not understand about your design is your jet tube and explanation is backwards from the truth?The pressure hose from the pump goes into the jet tube at an angle on a REAL dredge.Looking at yours the water is blasted in a straight line.....whats that do??Your suction nozzle although plastic looks right.

Lookin · Oct 23, 2008

Last winter, after considering building my own dredge, I bought a used 3" for about 1/4 the cost of a new one. It has metal parts and I don't believe I could have built it for the cost I gave for it. Considering the cost for an engine and pump, etc, I'd recommend searching for a used one.

With gold getting back down close to $700 and a lot of new dredgers out there who bought a new dredge this past spring realizing that they are not going to get rich prospecting, you can find a lot of great deals right now. Probably even more deals over the next several months. Just take a look on eBay! There are more and more dredges on there and many are going pretty much on the "cheap!"

Not that a homemade one can't be done - I don't think anyone here is saying that it can't be done - I think folks are just recommending to go with a system that has already been engineered to work rather than spending lots of time on hit or miss testing. If I built a homemade dredge, I think I would be running lots of tests to see how much color I am losing out the end of the sluice. In fact, I have done this with my "commercial" dredge that I feel like I "stole"!

At any rate, pissin' matches on this forum don't really help anyone determine what might be best for them to do.

Much gold to you all - homemade or not!

Lookin

flyspekau · Oct 24, 2008

He's got the pressure hose and suction hose backwards is all LOL as you can see in the diagram.

NOTHING ever goes right I dont care how you got things set up, even guys I know with brand new dredges have troubles with mechanics, hell I am on my 3rd dredge now in 3 years from a 2" then a 3" now the 4" all used but payed a lot less then for a new one but payed A LOT replacing and adding stuff , the 4 " after getting the frame stretched so I don't flip it was $200 another $80 in hose another $80 in a good foot valve another $50 for work on the box another $200 to work on leaking pontoons good thing I got the dredge for free oh another $50 for a new motor LOL its still less then a new $3,200 dredge but god the headaches but I am also learning a lot more with this journey.

EggyOG · Oct 24, 2008

He doesn't have the pressure hose and suction hose backwards. It is a diagram for a suction nozzle, and the basic design for that has the pressure hose aimed directly down the middle of the suction hose.

kuger · Oct 24, 2008

EggyOG said:
He doesn't have the pressure hose and suction hose backwards. It is a diagram for a suction nozzle, and the basic design for that has the pressure hose aimed directly down the middle of the suction hose.

I beg your pardon.....look at the last picture,that is wrong.I stated that the suction nozzle was correct.Do you realize there are two different jet systems??

cosmic · Oct 24, 2008

I'm not getting into this.. I would like to make one point.. If you start getting above 2-3" dredges the usual $200 trash pump won't make it.. A dredge pump is a high pressure volute type pump which not only supplies large volume, but also high pressure and high head pressure.. Still the best advice was given, is to buy used and avoid all the expense and aggravation of building someting that doesn't work or not as it should.. Then tweak it the way you want.. Can you build a dredge? Yes. you can, if you have the knowledge, tools and you like to build things.. But you might end up paying much more building and buying tools, than by buying a used dredge is more to the point..Russau and Hoser are highly respected for their knowledge and experience... My advise is to buy used..

EggyOG · Oct 26, 2008

Kuger,
I sell dredges. Yes I know their are two different kinds, but the underlying principle is pretty much the same. In fact, you could use the second set up as a suction nozzle with a length of 5 or 6 feet attached to it and it would work quite well. It has been done before, some studies (admittedly unscientific) actually claim it has greater suction that the jet design and also reduces the amount of plug ups compared to a nozzle. Would I try it? Only if someone else took the time to build it and hand it to me. I built a dredge once, I'll never do it again.

kuger · Oct 26, 2008

I have never heard of that Eggy,I like it if would cut down on plugups!!!! :wink:

Yea,I see no reason to build a dredge when so many used ones are laying around,you just need to keep your eyes open.You have to keep your dredges in tip top condition(work on them in the winter)and keep two or three of EVERY part. :thumbsup:

olga1913-Alaska · Oct 26, 2008

Hello,

An interesting topic but pretty uninspiring playground name calling. Over the years my partner and I have built our highbanker and our dredge. Neither are home made from the ground up. The riffles on the highbanker were cobbled from an old Keene dredge. Other than that we built it. We had very good fine gold recovery.

The dredge was built around a Proline factory jet, Keene pump, and swivel suction nozzle. We have had good luck with this set up.

http://www.fmtravels03.com/Images/PhotoAlbums/NEW STYLE/2008GoldGold/index.html
http://www.fmtravels03.com/Images/PhotoAlbums/NEW STYLE/2008GoldMining/index.html

I had a ball building these machines. They were great diversions for our dark Alaska winters. We have a couple of aluminum boat builders in town so we were able to round up their scrap material for each. I personally preferred to build than to buy used. We had experience on factory machines. We had dredges to reference in town. I read Von Mueller's book on the Spartan dredge.

I would recommend that anyone deciding to build that they first build around a factory jet. If you plan to move any amount of material you will at least want to start with a factory jet. They have evolved into a pretty good product that balances efficiency and durability. You can always build your own later and tinker with either variable. Make improvements with one and it comes at the expense of the other. I would avoid using PVC for a jet or a nozzle. Ten yards of gravel does funky things to factory jets. I would not want to carry around the number of PVC pieces that it would take to run that volume of material.

After building a couple machines I have a much deeper understanding of all of the variables involved with velocity, volume, grade, pressure and water disturbance than if I would have bought a used dredge. This has helped in making informed adjustments in the field.

I am sure there are plenty who disagree with me. I appreciate their views and await their responses. Those that want to be contrary for the sake of being contrary, please keep your comments to yourself because I really like coming here and reading other people’s ideas and accomplishments.

Bruce

russau · Oct 28, 2008

Bruce i did the very same thing as you. i made my own dredge and different equipment. my entire point was that at the end of the dredgeing season the prices for equipment go down and a lot of times this equipment can be bought cheap. sometimes cheaper than buying the parts/material for the job. and most of the time, bypassing makeing mistakes in the design. and for a first timer without knowledge in design or how this equipment works, it would be easier,cheaper and quicker for him to get into the water dredgeing with good results. can someone build their own equipment? ofcourse! a lot of people do! and i, like you have learned a lot from others as i built my equipment. and i also have learned from constructing this equipment, why it works or dont work from this knowledge. ive helped many people design/build equipment. am i the last word on building ,designing equipment? NO! not by a long shot! i still have fun making things and helping others.

flyspekau · Oct 28, 2008

I guess i'm wrong the suction nozzle system can be run from the jet? seems like it would work better up by the nozzle? still learning here thanks guys

Urban Prospector · Oct 28, 2008

Being well versed in hydraulics I figured building a dredge would be a snap. Getting suction from a venturi feed via h2o pump is really pretty easy stuff. What was really difficult for me was getting pontoons that would hold the weight of motor, pump, sluice, sand ,gravel and water that would all be floating above water line and still keep it all light enough to move. Once you start dredging the weight of the water and gravel in the dredge is fluctuating and causing balance problems that change the sluice angle and effect in turn gold retention. Keene and Companies like them have many years of scientific research and good ol fashioned trial and error to help determan weight and balance points.If your making a highbanker dredge combo on legs above the water it's fairly straight forward if you want it to float you mist consider how large a pontoon needed to carry the weight, what that weight will be in pounds of water, sand ,gravel, the machinery and any influences of maintenance/ clearing clogs. The weight must all so be supported at the optimum angle for success. I had most of what I'd needed in the Plant but the project still turned out to be more costly then buying a used unit that was proven ready to run.

Paul in WA · Oct 29, 2008

Be patient & save up some money. There are great deals to be found on used equiptment. I just bought a Keene 4 inch with air that is less than a year old, and looks like brand new for $1500 delivered. You'll sepnd more than that building one. The homemade PVC nozzle won't last long, the gravel will beat the hell out of it. Dredge parts are made of metal for a reason.

Paul