Dredge design suggestions

J

Jaxom

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No, i'm not asking where to get plans from! I'm sure you're all tired of see that asked every few weeks! :) I joined the GPAA back in '03 and '04. Had to let my membership lapse due to budget. (Babies are expensive!) During this time I use to hang out on the GPAA chat room and got tons of wonderful info and links from those guys over there.

But were I disagreed was what size of dredge and wiether I should build my own or not. Just about every one there said I'd be nuts go with anything smaller then 4". I disagree. The one creek I wanna do, and many I've sized up, if used anything that large I'd prob suck them dry!

Now why don't I just go buy a dredge. Well for starters...cost. Secondly and more importantly, they're general purpose. What I mean is they're designed to catch some fine gold and most nuggest. Well, here in the midwest and the land of flour gold.... nugget traps aren't nessary. If I do this right, any pickers I might happen upon, should be caught in miners moss or carpet or ribbed matting.

One of the best suggestions I got over at gpaa chat was being told about the DFS or Damn Fine Sluice. It's exclusivly designed to capture fine flour gold. It's concept comes from the alaskan beach boxes. It uses strickly wire mesh over miners moss with carpet below, above this is a small sheet of ribbed matting. So far it's gotten me some small dust, (nothing I'm even willing to brag about, but it's there). I also managed to get my hands on some rough sketchs of those Alaskan beach boxes as well. That's when I got to thinking...'wouldn't it be nice to get this out on the water...'

To capture fine gold, as I understand it, you need to a)elminate or classify out any larger material that may prevent capture of the fines. b)slow down the water giving the fine gold time to settle out of the flow of water.

So what I came up with is what I like to call a "Double Decker Quad Sluice System". Once I get all the bugs worked out, and I get the final cad design done, I'll post for all to see. Starting at the top, I'd put the boil box up higher on the dredge. (This is one of the tech questions I need answered later). The water and material will flow down from there across a punch plate with 1/4" holes 2'x2' wide. From this first classification water and material will drop down onto a plate with 1/8' holes that's 28" wide 36" long. after this it will flow across a sandwich of screen, miners moss and carpet. What's left will flow down onto the last for or so of the lower sluice box just incase... Underneath the plate I'll have ribbed black mat with very small riffles...mebbe 1/4' tall?

The lower box... Anything larger then 1/4' will hit a second boil box and then flow out on to an even wider plate, say 30-36" and 3' long. Just like the one above, under the plate have ribbed matting with small riffles and mebbe some angle iron attached vertically on the bottom to help spread the water out. Then again the lower half of the second box would have a sandwiched layers of carpet/moss/screen and on the bottom half of lower sluice have some 1/2" riffles. Just in case there's one of those small pickers in the area.

I hope that all made sence...wish I had the cad picture done so we could get a better visual... Now, here's my questions. What size pump to go with? I had thought about this small honda pump I had seen at a local tool store, I believe it's the same pump Keene offers with thier 2" backpack dredge. It rates at 100gpm. And while I'm not an engineer per say, it doesn't take a rocket scientist to realize that by placing the top boil box higher up on the dredge, this will effect the performance... Suggestions?

Pontoons... This is a biggie. More then likely, I'll be dredging by myself (unless I find a dredge partner here! :) ) so I need to keep things light and portable. Pretty much so I can wheel the whole rig into where I wanna go in one trip from my jeep. If I had my way, I'd be making the bottom sluice box 3' wide and 8' long, but I think this might just be too much to handle. Downsizing it to make it more managable, the bottom box will probibly end up 6' long and 30" wide. The question here is...what size pontoons? I've thought about buying those inflatble ones from keen. Think I'd need four total for this, not sure, since I won't know how much this will wiegh untill I'm done building it!

Okay, now I'm ready for any and all suggestions....or am I just nuts?

Jaxxx
 

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russau

Gold Member
May 29, 2005
7,250
6,701
St. Louis, missouri
i printed out your post and itll take some time going over all of the things that you want to do.just quickly, i thought you wanted something light and easy for one person to handel? i like the idea of yours for the muliti-tasking system but your getting way to complicated for the creek. dredge or highbank the material. work it out later at home! the simpler you keep your equipment the easier it is to make it work right! have your finer cleanup equipment at home for when you have time to do your cleanup and have a controlled setup!
 

russau

Gold Member
May 29, 2005
7,250
6,701
St. Louis, missouri
1)as far as cost........during the winters dredges go very resonable. almost beating the cost of materials to build it yourself(sometimes!)depending on how handy you are and if you have most of the material already. 2) the dfs sluice(i have one also) is for lesser amounts of water/flow than what a dredge uses. i have extended my DFS sluice another 24 inchs and i made my own flair from ABS plastic for a 2 inch suction nozzel and DFS sluice. i use my pump from my 2 inch proline dredge to supply water to the suction nozzel for pack-in areas.the DFS in stock design, is not long enough to make it work right for a dredge.3) the beach box is a added head ache to make work with the dredge. it is better used seperatly.my beach box is made of aluminum the base of it is 42 inchs wide with a 3 inch lip on 1 end and the 2 sides. it has black ribbed rubber matting the full length.and it has a 1/4 inch punch plate trough that is inclinded across the base. it has a hopper with a 3/8 inch grizzley to screen off the rocks. it is pictured over on www.iowagold.com(i think that site is still up??) but id like to see your project and better yet id like to see some good results from your test when its done.all of them are proven seperate projects, but combinded with the dredge would be a handfull to move/setup. but as a highbanker, it would/should be a lot better. your last paragraph stated about using a 2ftx2ft and a 28in x 36in boxs. these would be toooo wide even for a 4 inch dredge... a 5 inch uses these widths. i started out with a 20 inch wide sluice for a 5 inch dredge then dropped it to a 4 incher and my sluice slowed the material to much and it starved for water.so i made a new 16 inch sluice for my 4 incher.please dont let me dampen your project with my thoughts here. unless you have added water to each of these other sluices,youll starve them and the box will loadup! sure would like to see some pictures of your setup when you get time.
 

Jeffro

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Dec 6, 2005
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By the time you build such a monster, you would be saving money by buying a backpacker of some sort. :)
 

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Jaxom

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Jeffro,

Ya know, yer prob right! But like building a home computer, it might cost more then a Dell on sale, I'd still have that pride of sayin', "I built this!" :)

Russau,

Like some of the ideas and comment there! But let me explain my theories a bit more in detail. My orginal rought pencil sketch was nearly identical to an alaskan beach box. The reason I want it so wide, is to slow the water down. I do agree, I'll be doing my clean up at home. Actually I was thinking about doing the clean ups over the winter, and spend as much time as possible dredging during the warm months. I have a desert fox panner, and have most of the parts to build a small mini clean-up sluice around here minus a smallish pump.

But as I was saying, the orginal design was to just attach a boil box onto it and have that screend down to 1/4" and then let everthing else flow down the sluice. Mind you Alaskan beach boxes are 24" wide and 6' long. Again, the width is to spread the water out and slow it down letting the gold settle out. But once I drew the thing out, I noticed one flaw, if I built this just like those beach boxes, anything that's larger then 1/4" would be dumped right on top of my foot valve! That's where i started thinking I'd have to bring the water back forward again in a second slucie arrangement.

Being protable... While I admit I've never used a dredge before, I've seen enough of the gold fever shows, and talked to enough guys and gals that have. I'm fully aware of what it will take bring one in. Not only do you have the dredge, the motor, hoses, bucket(s), mebbe a lunch, shovel...and so on. What I was thinking if I designed this right, I could attach two large, either wheel barrel or dolly wheels on one end of the dredge and put some type of handle bar on the other, then I could wheel it in all by myself. Stick as much as I can in a back pack and rig some way everything else can be put on the dolly-dredge.

So, if a double decker type arrangement seems awkward, what if I go back to my orginal design? I still would like to go wider, even wider then the beach boxes. Let's say an 30" across, but instead of 6' feet long, say 8-10' long. No that may seem very long, but I could do it by making the sluice in two pieces. Using a couple of latches I could make a sandwitch of them with a large enough pocket (with the boil box being on the bottom) where I could stuff my hoses and other stuff. Again, I'd rig some large wheels to the bottom and a handle bar to the back to make it easier to move. Either way, it's something to concider.

Oh, I just wanna add something else, after I paid off a bunch of bills with my income tax refund, I had enough left, that I was able to buy myself a mig welder. Seems I've got a bunch of little projects that all need welding, and now that I'm not working, i'm thinking of going to school to get my welding certification.

Jaxxx
 

russau

Gold Member
May 29, 2005
7,250
6,701
St. Louis, missouri
a dredge vrs. a highbanker have different setups even though they are using the same principals.the dredge sucks up bigger material and isnt screened off from over the sluice. the highbanker is. the bigger your material the more water you need. also the wider your sluice the more water you need. im not saying that your design wont work! it will if you have plenty of water(big pump/eng.) you would need extra spray bars for each sluice that you install to keep the material from loading up and keep the material flowing. on a highbaker that wouldnt be a problem with setup. on a floating dredge, it would be a rough task to do and keep it floating level, and trying to keep the weight down for one person to handel or muchless float correctly.my beach box incorperates some of these ideas(multi-sluices). as is your setup would be a rough thing to do!but i guess it could be done but only for calm waters without much of a current.
 

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