Bought 4" Dredge...have questions now

omnicron

Bronze Member
Jun 14, 2012
1,017
409
Caldwell, Idaho
Primary Interest:
Prospecting
Hey guys, Finally bought myself a a 4" dredge. It's a older dredge built by Gold Dredge Builders Warehouse. It was kind of a lot buy, this nice guy had a 4" dredge with air for sale for 1500 but gave me the option to buy everything he had for $2000. I ended up with the 4" dredge, homemade 2" dredge with an keene pump, a mini-highbanker, a gold wheel, 4 wetsuites, 4 regulators and a bunch of tools. All in all I think I did alright.
So on to my questions I guess... The 4" dredge has a Subaru engine, the pump on the engine has 350 (casting?) on it. Is this the gpm's? What kind of preasure should it put out? It has a air compressor also but I don't find any markings on it, looks like t80s but its grey. Last but not least and the most important for me is the sluice, It's not the sluice on their current model, it measures 15" accross. I'm wanting to build my own 3 stage over under sluice with double classifying screen based on this » Double-screen Classification System in Dredging. Unfortantly they are not giving any measurments or such and I havn't found any decent info on other styles. Can anyone here help out a guy out? I need to know stuff like how big of an opening I need for the lower sluice, how far above the raised expanded to put the bottom of the upper plate and so forth. I know that mods with have to be made based on the type of material being ran and so forth. I need a ball park or better yet, exact setting the start at. Here is a pic of my new baby:

IMG_20130210_192316.jpg

Thanks and I'm sure I'll have more questions and will post pics of the other stuff I got if anyone is interested.
 

Sounds like you got a nice buy!

Unless you have signicant experience with this type of sluice, my suggestion would be to run it as is first, & see how it does. then modify it as needed.
 

Keene used to sell a conversion kit to make an over/under, but it soon began to interfere with sales of O/U , so they discontinued it .Can't blame them, too bad though
 

The grey t-80 is a newer model than the blue ones.
I could use another regulator if they all work and 4 is more than you need.
Personally I like the robin subaru engines better than anyother including honda.
Looks like you got a great deal.Call Alan Trees and he can tell you all about that pump and dredge.
You can get his number from gold dredge builders website.
 

The grey t-80 is a newer model than the blue ones.
I could use another regulator if they all work and 4 is more than you need.
Personally I like the robin subaru engines better than anyother including honda.
Looks like you got a great deal.Call Alan Trees and he can tell you all about that pump and dredge.
You can get his number from gold dredge builders website.

Good to know that my pump is an newer model. I am not sure if all the regulators work or not, I'm hoping to run it here this weekend and I'm going to check things out but I wont be lookin for gold.
 

Sounds like you got a nice buy!

Unless you have signicant experience with this type of sluice, my suggestion would be to run it as is first, & see how it does. then modify it as needed.

Thanks for the warning but I have full confidence I can handle it, besides, the place I was working in '12 had very fine gold so I need every advantage I can get!
 

Keene used to sell a conversion kit to make an over/under, but it soon began to interfere with sales of O/U , so they discontinued it .Can't blame them, too bad though

I don't blame them, why kill your main income by selliing upgrades to people!
 

omnicron said:
Thanks for the warning but I have full confidence I can handle it, besides, the place I was working in '12 had very fine gold so I need every advantage I can get!

I think what he's trying to tell ya is you need some experience with that machine befor you start fixing what's not broke!!!!!
The advantage you will have with a over under setup won't even help ya until you have had some basic time dredging
There a lot too learn .alot more than most folks think !
Good luck too ya looks like a good unit and also might just consider buying a newer box from Alan trees
Is more time dredging and finding gold and less time fixing things
Personally I would just run it the way it is.
 

I think what he's trying to tell ya is you need some experience with that machine befor you start fixing what's not broke!!!!!
The advantage you will have with a over under setup won't even help ya until you have had some basic time dredging
There a lot too learn .alot more than most folks think !
Good luck too ya looks like a good unit and also might just consider buying a newer box from Alan trees
Is more time dredging and finding gold and less time fixing things
Personally I would just run it the way it is.

I dredged this last year with a homemade 2.5" suction dredge/highbanker. Did good too. I built a sluice based on Alan Trees' and pop and son's design and stopped the gold loss I was getting with the a52 and dredge riffles. I would love to build that box for my 4" but It wont fit without major mods done to the frame. So, I'm going to build the next best thing.... a over/under box
 

Well sound like your on the way

Over under setup are pretty simple just make sure you give,yourself plenty of flow control to the lower section at times you'll want a little more while other time you'll want it slower .
Personally I,would design it simlar to keenes 3stage box they use now . My only complaint it that you can't see the under sluice without breaking it down .
I meet a lot of people who don't like the keene boxes because,the think they load up the underflow but if look a little closer they really are not loading in most cases
,
But where the box first drops you have a low presure area that gathers sand gravels ect and it looks like its plugged up but if you run your fingers back in the riffle area you'll find it doing like it should ! At least in most cases you will always find folks who will,overload the dredge with sand ect and blame the dredge for there mistakes and lack of dredging knowledge
 

Sounds like you got a good deal. Some things you might consider getting: Replace all "worm gear" hose clamps with good clampco hose clamps, oversize jet-log coupler, digital engine tachometer/hour meter, brass fittings for all air connections, make some way to adjust the angle of your flair.

I run the Keene 3 stage box on a 4" and it can do OK on finer gold with some modification.

Reed Lukens has some good videos on dredge sluice building/tuning on his YouTube channel.

The most common mistake I see people making when running the stock undercurrent Keene boxes when it comes to finer gold is too much throttle. The reality is though, since they are all stock, they have no choice. The undercurrent is buried under the water surface and the 2nd stage riffles take considerable energy/slope to keep from loading.

The most recent change to mine is a screened 2nd stage. The box is now fully screened from 3/8" in the first stage to 3/16" for the 3rd and 1/8" for the second stage. Fines recovery continues to improve but its a work in progress. The next change will be adding another 1"+ to the box elevation to allow for more slope while keeping that undercurrent just out of the water. This will bring the total lift to +3" over stock.

As you can see in the video, the new 2nd stage is catching a lot of heavy fine material that does not drop into the 3rd stage despite relatively low rpm's and shallow box slope. The increased slope should help keep it from loading/packing so much, hopefully. Good luck with your new setup and let us know how it goes.

 

specksandflecks said:
Sounds like you got a good deal. Some things you might consider getting: Replace all "worm gear" hose clamps with good clampco hose clamps, oversize jet-log coupler, digital engine tachometer/hour meter, brass fittings for all air connections, make some way to adjust the angle of your flair.

I run the Keene 3 stage box on a 4" and it can do OK on finer gold with some modification.

Reed Lukens has some good videos on dredge sluice building/tuning on his YouTube channel.

The most common mistake I see people making when running the stock undercurrent Keene boxes when it comes to finer gold is too much throttle. The reality is though, since they are all stock, they have no choice. The undercurrent is buried under the water surface and the 2nd stage riffles take considerable energy/slope to keep from loading.

The most recent change to mine is a screened 2nd stage. The box is now fully screened from 3/8" in the first stage to 3/16" for the 3rd and 1/8" for the second stage. Fines recovery continues to improve but its a work in progress. The next change will be adding another 1"+ to the box elevation to allow for more slope while keeping that undercurrent just out of the water. This will bring the total lift to +3" over stock.

As you can see in the video, the new 2nd stage is catching a lot of heavy fine material that does not drop into the 3rd stage despite relatively low rpm's and shallow box slope. The increased slope should help keep it from loading/packing so much, hopefully. Good luck with your new setup and let us know how it goes.

Video Link: http://youtu.be/t2DkThxLkcM

Keeping the under current out of the water is going to cause too much flow in that box .
And add to the wash down there
Of you will inspect your entire 3rd stage area you will see what I'm seeing in your vidieo
It's washed and the only part that's not is where the box first drops this is caused by the low presure created by the drop
In the box! You will always have a loaded up area in the first part of of the 3rd stage of the box unless your running it wrong
But if you watch the rest of the third stage it should not be as clean as what I'm seeing in your video


I would not run your box this way you can resolve the problems in your second stage area by removing every other riffle in that section!


That box was designed to run with the underflow section in the water and to control the curent in the third stage by closing it off some if needed
When you run the third stage area out of the water it will flow too much even if its closed off most of the way
 

G1sammons said:
Keeping the under current out of the water is going to cause too much flow in that box .
And add to the wash down there
Of you will inspect your entire 3rd stage area you will see what I'm seeing in your vidieo
It's washed and the only part that's not is where the box first drops this is caused by the low presure created by the drop
In the box! You will always have a loaded up area in the first part of of the 3rd stage of the box unless your running it wrong
But if you watch the rest of the third stage it should not be as clean as what I'm seeing in your video

I would not run your box this way you can resolve the problems in your second stage area by removing every other riffle in that section!

That box was designed to run with the underflow section in the water and to control the curent in the third stage by closing it off some if needed
When you run the third stage area out of the water it will flow too much even if its closed off most of the way

Also spec your washing a lot of larger flakes in your second stage with that screen like that !
 

G1 I know you THINK are trying to help here, but you are making some (many) incorrect assumptions. You might assume these are all my own ideas for improving recovery of fine gold when actually they come from those with far far more knowledge than you or I will have for some time yet. Not only have I heeded the advise given to me by those who were dredging before you were born. I have run my own tests over a couple hundred hours nozzle time.

Also there is no point in destroying the stock 2nd stage riffle. They work fine for what they are intended to do. Any miner worth their salt knows you have to tune a box for the majority of gold in the deposit. This hasn't changed in over a hundred years. LEARN TO DO YOUR OWN TESTING IN YOUR OWN DEPOSIT NO MATTER WHAT, PERIOD.

The 3rd stage was not shown in that video, but if you need to see what they are supposed to look like... This is after floating the dredge around and getting it up on the bank so the cons have shifted somewhat but I think you should still get the picture.

Also spec your washing a lot of larger flakes in your second stage with that screen like that !
Really? What size flakes? Whats the corey shape factor? WHERE DID THE FLAKES GO? :tongue3::laughing7:



Not trying to hate on ya dude, but I have to laugh at you telling me how to run in a place you have never mined. Hope the dredge hose worked out for ya!:laughing7:
FFR- Your advice is never unwelcome, It just doesn't carry much weight with me ATM.
 

Wrong I could clearly see you third stage expanded metal clearly washed ! WATCH YOUR MOVIE AGAIN AND YOU WILL SEE!

Also iv done a lot of testing and you can't run you underflow out of the water with the plate in any position ! It will flow way to much !
This looks just like what folks do who put life jackets and float under there boxes to keep them out of the water because they think the box should be out of the water
When actually the box was designed to run in the water !
Looks its your box run it how you want but when you go offering advice to someone your fair game
And when you think your to smart to listen to advise from anybody without stopping to look and at least offering a explnation as to why your doing these things
Then your too dum too learn anything
 

Look speck o fleck

What I'm telling you wasn't my observation it was that of the engineer who built that machine your running !
I tried all these thing when I bought my machine and had the opertunity to have a lengthy conversation with the man who designed these and I got myself straightened out!

As for flakes washing out your second stage maybie you don't play in those kinds of areas but most dredgers do .
And 1/8 punch plate it the wrong idea for your last chance ,
Iv pulled larger flakes out of my second stage than the holes in your punch plate !!!!!!!!
That's what I was trying to,explain to ya
But like I said its yours run it how you would like !
But when your offering advise you also have to realize that there not sampling the same materal or working the same area as you
 

Omg speck

Your the fella playing in that crack .lmfao
Now I understand !
I know you think you know way more but buddy iv watched many of your post and not just on treasure net
I remember Reed talking to you when you first started this mod couple years back and it seems to me that most of the experience dredger you have talked with
Weren't recommending these but trying to get you back on track .
Your one of those legends in your own mind
Understand I don't care if you like my advise or not ! Your just a piddle bug your not even a dredge!
 

Omnicron, I talked with someone who was making the double screen system a couple years ago. I was also planning on making the screen decks myself, but wanted the custom underlay which he was having farmed out at the time. I don't recall for sure if it was Mike Dunn (925-825-4653) I spoke with or someone with another shop. I also read about it first on the new 49ers forum. We had a long conversation and he was very helpful in describing the system and offering advice on the best methods to secure the underlay and design the elevation adjustments on the screen decks. The underlay was a bit spendy due to it being cast by a 3rd party in limited numbers at the time.

Anyway I would give him a call or maybe contact Jim Foley through the new 49ers.
 

Can't we just all get along? Seriously guys, I'll tell you the same thing I say to my kids, take it out side and beat the crap out of each other. Just don't do it here!

With that said, guys thanks for the info. I just started cutting the peices for my new box. I bent up a new box and plasma cut the inner peices. My middle divider is going to be
1/8" thick alum. The alum I get from work is tempered, super durable but you can only bend it once, after that it'll break. My plan is to build this in sections just like they did on the new 49's box. I like the idea of being able to clean out in sections that way I can tell what changes need to be made based on were the gold's location in the box. I was wanting to weld up the sides and divider but I still dont know how much space to allow for the under current section. I'm going to make everything adjustable but would like to know a base line to start from.

Specks, you have an over/under box right? Could you give me a measurement from your bottom tray to the divider? How about how long your high grader section is. These are things I cant tell from videos.

Thanks to all who have contributed!!!
 

omnicron said:
Can't we just all get along? Seriously guys, I'll tell you the same thing I say to my kids, take it out side and beat the crap out of each other. Just don't do it here!

With that said, guys thanks for the info. I just started cutting the peices for my new box. I bent up a new box and plasma cut the inner peices. My middle divider is going to be
1/8" thick alum. The alum I get from work is tempered, super durable but you can only bend it once, after that it'll break. My plan is to build this in sections just like they did on the new 49's box. I like the idea of being able to clean out in sections that way I can tell what changes need to be made based on were the gold's location in the box. I was wanting to weld up the sides and divider but I still dont know how much space to allow for the under current section. I'm going to make everything adjustable but would like to know a base line to start from.

Specks, you have an over/under box right? Could you give me a measurement from your bottom tray to the divider? How about how long your high grader section is. These are things I cant tell from videos.

Thanks to all who have contributed!!!

Sorry about that omni !
Just can't stand folks who are that disrespectful to others
I was only offering things iv learned And didn't disrespect any body untill he came down the pipe with his thoughts on how much weight my option carried
When I realized who he was
1 pic is shaped together like it would be dredging .but it will very on you mat carpet ect . The rails on the riffle section are 1" tall
2 pic how long the separation pan is and I didn't measure the scope on the front
3 pic is how long the under riffle sec is
4 pic the front section where the box first drops
5 pic is 1 3/8 front view of the drop section
If ya need more just let me know I have both a brand new box and a older one sitting in the shop
 

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